Decarbonising Energy: the Developing International Activity in Hydrogen Technologies and Fuel Cells

Journal of Energy Chemistry 0 0 0 (2020) 1–11

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Journal of Energy Chemistry

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Review

Decarbonising energy: The developing international activity in hydrogen technologies and fuel cells

∗ John Meurig Thomas a, Peter P. Edwards b, , Peter J. Dobson c, Gari P. Owen d a Department of Materials Science & Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK b King Abdulaziz City for Science and Technology (KACST)-Oxford Centre of Excellence in Petrochemicals and Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR, UK c The Queen’s College, University of Oxford, Oxford OX1 4AW, UK d Annwvyn Solutions (Independent Consultant), Bromley, Kent BR1 3DW, UK

a r t i c l e i n f o a b s t r a c t

Article history: Hydrogen technologies and fuel cells offer an alternative and improved solution for a decarbonised energy Received 11 February 2020 future. Fuel cells are electrochemical converters; transforming hydrogen (or energy sources containing hy-

Revised 31 March 2020 drogen) and oxygen directly into electricity and heat. The hydrogen fuel cell, invented in 1839, permits Accepted 31 March 2020 the generation of electrical energy with a high eﬃciency through a non-combustion, electrochemical pro- Available online xxx cess and, importantly, without the emission of CO 2 at its point of use. Hitherto, despite numerous efforts Keywords: to exploit the obvious attractions of hydrogen technologies and hydrogen fuel cells, various challenges Decarbonisation have been encountered, some of which are reviewed here. Now, however, given the exigent need to ur- Hydrogen Energy gently seek low-carbon paths for humankind’s energy future, numerous countries are advancing the de- Hydrogen Economy ployment of hydrogen technologies and hydrogen fuel cells not only for transport, but also as a means of

Fuel cells the storage of excess energy from, for example, wind and solar farms. Furthermore, hydrogen is also be- Environment ing blended into the natural gas used in domestic heating and targeted in the decarbonisation of critical, Sustainability large-scale industrial processes such as steel making. We brieﬂy review speciﬁc examples in countries such as Japan, South Korea and the People’s Republic of China, as well as selected examples from Europe and North America in the utilization of hydrogen technologies and hydrogen fuel cells. ©2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Sir John Meurig Thomas is one of the founders of solid- Peter P. Edwards FRS ML holds the Statutory Chair of state chemistry and the surface and materials chemistry Inorganic Chemistry at Oxford and is the Co-Director of of solids. He was one of the first chemists in the world to the KACST-Oxford Centre of Excellence in Petrochemicals, use electron microscopy as a chemical tool, which he ini- also at Oxford. He has previously held positions at Birm- tiated in the University of Wales (Bangor) in 1964. He has ingham (Professor of Chemistry and of Materials), Cam- made numerous studies in heterogeneous catalysis and bridge (Lecturer in Chemistry and Director of Studies in made significant contributions to the study of minerals, Chemistry, Jesus College) and Cornell (British Fulbright especially silicates, zeolites and clays as well as graphite Scholar and National Science Foundation Fellow). He was and diamond. For his contributions to geochemistry, a Co-Founder of the first-ever UK Interdisciplinary Research new mineral, Meurigite, was named in his honour. He Centre, that in Superconductivity at Cambridge and the was once head of Physical Chemistry in the University of UK Sustainable Hydrogen Energy Consortium (UKSHEC). Cambridge and Director of the Royal Institution of Great He has been Chair of the European Research Council Ad- Britain. vanced Investigators Award Panel on Chemical Synthesis and Advanced Materials. Edwards is Fellow of the Royal Society; Einstein Professor of the Chinese Academy of Sciences; Member, German Academy of Sciences, Inter- national Honorary Member of the US Academy of Arts and Sciences; International Member of the American Philosophical Society, and Member of the Academia Eu- ropaea. His current major interests include: Targeted reconstruction of plastic waste to hydrogen and starting monomers; converting carbon dioxide to carbon-neutral fuels and Green hydrogen from fossil hydrocarbon fuels.

∗ Corresponding author. E-mail address: [email protected] (P.P. Edwards). https://doi.org/10.1016/j.jechem.2020.03.087 2095-4956/© 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved. 2 J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11

Peter Dobson covers a wide range of disciplines from Box 1 . HYDROGEN TECHNOLOGY: THE NEW LOGISTICS physics and chemistry to materials science and engineering. He has also worked in industry (Philips) as well as academia (Imperial College and Oxford) and was re- Over recent years there has been a trend for an increasing

sponsible for creating and building The Begbroke Sci- amount of on-line shopping with major debates about the ence Park for Oxford University. He has published over

180 papers and 33 patents. He has founded 4 companies social implications of this on communities. Intuitively, this and advised on the formation of 8 more. He was (2009- leads to fewer private car journeys although discussion with 2013) the Strategic Advisor on Nanotechnology to the Re- transport oﬃcials reveals that this is a more complex situa- search Councils in the UK and currently sits on the EPSRC tion than it appears in view of increased deliveries. Neverthe- Strategic Advisory Board on Quantum Technology. He was less, there is an increase in distribution centres and this pro-

awarded the OBE in 2013 in recognition of his contribu- vides a real world example of a use case for a fuel cell pow- tions to science and engineering. He is a Visiting Profes- sor at King’s College London and at UCL. Peter delivers courses at Graduate level in ered vehicles –thefork lift truck for moving goods within the areas of healthcare, biosensors, energy, nanotechnology, manufacturing, innova- the distribution centre and the use of uncrewed air vehicles tion, entrepreneurship and related topics and advises companies and inventors on (UAVs) for “last mile” home deliveries. innovation. Already, there are 25,0 0 0 fuel cell powered fork lift trucks in use in the US [3] . Amazon is investing in this technology [ 4 , 5 ]. Amazon Prime Air is expected to start a drone deliv- Gari Owen was educated at the University of Wales ery service in selected cities by the end of 2019 [6] . There (1967-1973) and worked for 30 years in Government are proposals [7] by several suppliers for hydrogen fuel cell (Home Oﬃce and Ministry of Defence) in research and powered drones for this purpose on the argument that these

development, international programmes and identifying UAVs typically have 3 times the radius (9 times the area cov- new requirements. Since 2003, he has been a Consultant

to Government and Industry in the ﬁelds of defence, se- erage) of an equivalent battery operated vehicle. curity and future technologies. He has also served as an This is an example of how a change in societal behaviour adviser and stakeholder on various EC (FP7 & H2020) pro- leads to the adoption of technology for both technical and grammes. commercial reasons in an unforeseen way.

2. Historical background 1. Introduction Fuel cells are electrochemical converters, transforming hydro- Numerous countries across the world are now urgently en- gen (or hydrogen-containing fuel feedstocks) and oxygen directly, gaged in seeking ways of securing a low-carbon or decarbonised with high eﬃciency, into electricity and heat with only water as energy future for humankind. In particular, the merits of moving the emission product at their point-of-use. The electrochemical away from vehicles powered by fossil fuel internal combustion en- cell is one in which the free energy of combustion of a chemi- gines towards battery-operated vehicles are being strongly advo- cal fuel is directly converted into electrical energy – remarkably, cated and enthusiastically implemented [1] . without the aerial combustion process and the concomitant emis-

In a major study, the US National Academy of Sciences has ad- sion of CO2 . The notion of a fuel cell goes back to the invention dressed many of the challenges of achieving a future dominated by by William R. Grove, a lawyer and amateur electrochemist [ 8 , 9 ]. carbon-free energy [2] . Grove used two platinum electrodes dipping into an electrolyte, In this article we highlight here several vignettes that reflect a at one of which hydrogen underwent the following catalytic re- → → + + − complementary approach; namely, the implementation across the action: 2H2 4H (ads) 4H 4e ; and at the other, the reac- + + + − → globe of hydrogen energy technologies and hydrogen fuel cells as tion: O2 4H 4e 2H2 O. The overall process is then simply: + → a route to the effective decarbonisation of transport, energy and 2H2 O2 2H2 O but with a generated electric current now flow- manufacturing. Our aim is to demonstrate that commendable tech- ing into an external circuit. Grove himself regarded his invention as nological solutions in this area are currently being implemented to a gas cell. And in a famous letter that he wrote to Michael Faraday help redress the adverse environmental effects of our carbon-based in 1842, he described it as a “curious voltaic pile” (see Fig. 1 ). energy sector. We are convinced that the prospects of hydrogen as A useful summary of the different types of fuel cells that have an energy carrier or vector will, if appropriately implemented, ulti- since been developed has been produced by the US Department mately help humankind towards our goal of a low- or zero- carbon of Energy [10] , and a typical widely-used fuel cell is the so-called energy future. proton exchange membrane fuel cell, depicted in Fig. 2 . In addition to discussing the adoption of hydrogen fuel cells for The term “fuel cell” was coined by the industrialist Ludwig transport, we also discuss their uptake as stationary power sources Mond who in 1889 advanced the critical finding that this electro- and domestic systems, and the conversion of natural gas networks chemical oxidation of hydrogen [11] , rather than the oxidation of to a hydrogen mixture as a means of significantly reducing the hydrogen in an aerial combustion process, was the thermodynam- emission of CO2 . We also outline increasing efforts to utilise hydro- ically more efficient process for releasing energy (see later). Since gen in critical, difficult-to-decarbonise, high- CO2 emission manu- hydrogen could be continually fed to the cell, Mond regarded it as facturing industries, e.g. steel-making. There also exist applications a “fuel” and Grove’s electrochemical cell was no longer described that are inherently technically challenging for conventional battery as a battery, but rather as a “fuel cell”. sources, but not for hydrogen fuel cell power applications, partic- The Nobel Prize winning chemist, Wilhelm Ostwald [12] also ularly heavy transport including buses, trucks, rail and maritime realised that, in principle, the electrochemical generation of power applications such as ferries. The increasing large-scale use of fuel was much more efficient than the conventional combustion of fos- cell powered forklift trucks and the proposed used of drones are sil fuels. Ostwald, therefore, speculated that it might be possible to examples of an unfolding revolution in the application of hydro- electrochemically “burn” coal and he further speculated whether gen fuel cell technology in logistics, see Box 1 . The superiority of this would be the 20th century method of choice for generating hydrogen fuel cells in these instances is not in doubt. power. J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11 3

Fig. 1. Copy of Grove’s letter to Faraday 2 (a) in which he describes his “curious voltaic pile” (Copyright ©Royal Institution of Great Britain). After John Meurig Thomas, W.R. Grove and the fuel cell. Philosophical Magazine 92 (2012): 3757–3765 and (b) Grove’s 1839 fuel cell (Wikipedia).

Fig. 2. Simpliﬁed illustration of a modern hydrogen fuel cell (sivVec- Fig. 3. ( Fig. 2 of Royal Society Biographical Memoir of F. T. Bacon). Man’s ﬁrst step tor/Shutterstock). on the moon —the photograph dedicated to Francis Thomas Bacon by the Apollo 11 astronauts. (NASA/Public domain).

2.1. Francis Bacon and fuel cells

A century after the pioneering demonstration by Grove, the epic voyage, a point also deeply appreciated by the astronauts (see first practical hydrogen-oxygen fuel cell was developed by Francis Fig. 3 ) Indeed, President Nixon told Bacon, "Without you Tom, we Thomas Bacon (a direct descendent of the Francis Bacon of Novum wouldn’t have gotten to the moon.” Organum fame), who began his influential studies in fuel cells in That period marked a significant and highly successful advance the mid-1930s [13] . in the precisely targeted application of hydrogen fuel cells in the Notably, his patents for the fuel cell were licensed by the US US. It was, obviously, pursued as a prestige project and cost- Company, Pratt & Whitney, to provide electrical power for the effectiveness was essentially disregarded. Apollo moon mission in 1969. Remarkably, it was largely Bacon’s Bacon gave a memorable Friday Evening Discourse at the Royal work that enabled the Apollo 11 crew to partly power their craft Institution of Great Britain on 12 February, 1960 [14] . During the and also to produce clean, drinking water for them during their course of his presentation he said: 4 J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11

“The efficiency of all heat engines, that is to say, engines in which heat is converted into mechanical work, is governed by Carnot’s cycle; this means that the efficiency is limited in practice by the difference in temperature at which the heat is taken in by the working fluid and the temperature at which it is rejected. It is the possibility of avoiding the Carnot limitation which constitutes the main, but not the only, reason for interest in fuel cells ”. Apart from the merits described extensively elsewhere [15] , Ba- con (who used an alkaline electrolyte in his cell) emphasized that fuel cells operated silently, and that they were independent of the prevailing conditions of the wind or the sun. Interestingly, he also advocated using nuclear reactors to electrolyse water so as to build up adequate storage of hydrogen for future use in fuel cells, an idea put forward again recently (2019) by Rolls Royce plc [16] .

2.2. President George W. Bush and the hydrogen fuel cell

In his State of the Union address on January 28, 2003 [17] , Pres- ident George W. Bush made the following statement : “With a new national commitment, our scientists and engineers will overcome obstacles to taking these (hydrogen fuel cell cars) from laboratory to showroom, so that the ﬁrst car driven by a child born today will be powered by hydrogen and pollution free”. Fig. 4. An idealisation of a hydrogen energy economy in which hydrogen, in association with fuel cells, becomes the principal energy vector connecting production

Whilst, in retrospect, President Bush’s remarks may now ap- to consumption. From P.P. Edwards et al, Energy Policy 36 (2008) : 4356–4362. pear overly optimistic, it must not be forgotten that as early as 1966, General Motors (GM) in the US developed the first fuel cell road vehicle, the Chevrolet Electrovan [18] . The Electrovan was The term is often associated with a cleaner future energy econ- considered the most advanced electric vehicle ever built at the omy, which increasingly relies more heavily on renewable or sus- time. As the first fuel cell powered automotive vehicles, it was tainable rather than fossil energy sources, and in which hydrogen, rated as a major technical achievement in 1966. In 2007, GM as a secondary energy carrier, will be the principal currency for the launched “Project Driveway,” a 119-vehicle fleet of hydrogen fuel transfer of chemical potential energy. One can therefore distinguish cell-equipped Chevrolet Equinoxs that were driven in daily use for between a sustainable hydrogen economy, in which fossil fuels can more than 3 million miles by more than 5,0 0 0 consumers. It was play no part, hydrogen production is achieved without them, and the world’s largest fuel cell vehicle fleet ever assembled at the a transitional hydrogen economy, in which hydrogen will almost time. It eloquently demonstrated the viability of a hydrogen based certainly be generated using fossil fuels (for example, by the steam transportation system. reforming of methane) while an infrastructure for hydrogen production, distribution, and end utilization, for vehicular transporta- 3. International strategies towards hydrogen technologies and tion especially, is established. hydrogen fuel cells A 2008 representation of the essential ingredients of a possible hydrogen energy society or economy is shown in Fig. 4 . We present here a brief overview of several international efforts centred on: 4. Activities and developments in a global context (i) Using hydrogen as a secondary energy vector. Excess electrical power generated from renewable energy sources –such as 4.1. In Japan wind and solar –then being used for the production of hydrogen by electrolysis. This hydrogen can be used for (ii) and (iii) Several years ago the government of Japan had expressed their below, in addition to large-scale industrial processes for ammo- strong intention to implement a Hydrogen Society ( Fig. 5 ). Indeed, nia and steel production. this concept of a hydrogen-based society or economy has been un- (ii) Harnessing hydrogen fuel cells as key energy providers, not der continuous consideration in Japan since 1993 [20] . only for transport (land, air and maritime), but also in station- For more than 30 years in downtown Tokyo and many other ary power sources. Japanese cities, many shopping malls, schools, hospitals and other (iii) Developing the putative conversion of domestic natural gas net- centres of population have been successfully powered by hydrogen works to ones operating solely, or partially, with hydrogen, a fuel cells.

conversion that would massively reduce the emission of CO2 In March 2019, the Fuel Cell and Hydrogen Energy Association into the atmosphere. (FCHEA) published [21] several key facts that reflect the extent of activities being pursued in Japan concerning fuel cell development. In so far as defining what, precisely, is meant by a hydrogen The view expressed in that report is that hydrogen fuel cells, as a society or a hydrogen economy, one of us (Peter P. Edwards), with power source for several modes of transportation as well as sta- colleagues, has previously outlined a possible working definition tionary and other mobile applications, will allow Japan to signif- [19] . icantly diversify and strengthen its national energy infrastructure. A future ‘‘hydrogen energy economy’’ is one in which the dominant In addition, the resulting independence from the fossil-fuel driven role currently played by fossil fuels as an energy vector, especially electric grid that distributed electrical power from hydrogen fuel in personal transportation, would instead be fulfilled by hydrogen, cells achieves would achieve is seen as a route to enable Japan almost invariably associated with the extensive use of fuel cells. to move towards a more self-sustaining, clean and secure energy J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11 5

Fig. 5. Japan‘s Strategic Roadmap towards a hydrogen society after New Energy and Industrial Technology Development Organization (NEDO) from 6 th International Workshop on Hydrogen Infrastructure and Transportation, 11–12 Sep 2018. Originally from METI briefing, June 23, 2014. future. Encouraged by their Prime Minister, Shinz o¯ Abe, the coun- been published and includes (Fig. 8 ibid) specifications of fuel cells try’s aim is to reduce the price of hydrogen fuel to as little as a for business and industry use [24] . fifth of the 2018 price. In this way, Japan aims to reach a target of In December 2019, Japan launched the world’s first liquefied hy- 40,0 0 0 fuel cell electric vehicles on its roads by 2020 and 80 0,0 0 0 drogen transport ship –the Suiso Frontier –with construction ex- by 2030. To support such a large-scale increase, the Japanese Gov- pected to be completed in late 2020. This will be used for ship- ernment also plans to enact new regulatory reforms to accelerate ping hydrogen from Australia and demonstrates a commitment to the construction of hydrogen fuelling stations, up to 320 Nation- the hydrogen society in Japan [25] . However, this raises several wide by 2025. significant issues. A think tank (the Australia Institute) claimed Advanced uses have also been made of stationary power in November 2019 that the projections for Australia’s hydrogen sources that use fuel cells. These operate quietly and have ex- roadmap inflates the market requirement for hydrogen by Japan tremely low undesirable emissions, so that they can be installed and South Korea by a factor of 11. Initially, the hydrogen would more or less anywhere and can be part of a micro-grid configu- be produced in Australia from lignite –brown coal– and a fossil ration and, notably, useful at times of natural disasters for use in fuel-based hydrogen export industry will almost certainly result in off-grid regions. Importantly, they provide power on-site directly to increased Australian emissions. Japan’s main incentives are energy customers without the efficiency losses of long-range grid trans- security and lower domestic emissions. In effect, this can be seen mission. as exporting CO2 emissions to Australia [26]. The Tokyo Metropolitan Government (TMG) aims to develop Brown, coal-based hydrogen production could make it possible a CO2 -free hydrogen power source for extensive use during the to capture and sequester the CO2 in bulk as the by-product of the Tokyo Olympic/Paralympic Games. All official vehicles to be used production process Nevertheless, this does not appear to be a pri- during the Games will be fuel cell powered. Moreover hydrogen ority in the pilot project. If so-called “Green hydrogen” production as a source of energy will be used throughout the event; and hy- from electrolysis using renewable energy is developed, the obvious drogen pipelines are to be installed in the Olympic Village, the ul- issue is thereby raised as to “…whether a drought-stricken country timate aim being that an Olympic “Hydrogen Society” will be one like Australia would be keen on sending fresh water overseas in the of the enduring legacies of the Games. 1 The plan by TMG is to form of hydrogen” [27] . use some hydrogen produced by electrolysis using at least some renewable energy generated at a new facility in Fukushima Pre- fecture [23]. It is intended that hydrogen refuelling stations during 4.2. In China the Games will be installed in industrial areas and districts, so that these may be harnessed to supply domestic electricity and to heat In December 2016, China’s 13th Five-Year Plan included a Na- municipal buildings. The overall aim is to facilitate new business tional Fuel Cell Technology Roadmap, which laid out ambitious tar- models for using hydrogen in residential areas. An excellent review gets for hydrogen fuel cell and hydrogen energy development, pri- of hydrogen technologies and developments in Japan has recently marily for transport. The Roadmap called for over 1,0 0 0 hydrogen- refuelling stations to be in operation by 2030, with hydrogen production mainly coming from renewable resources. In addition, the 1 A s the iconic Bullet Train remains for the 1964 Games [22] . The Games, originally scheduled for 2020 have now been postponed until 2021 as a consequence of the Roadmap set a target for over 1 million fuel cell electric vehicles COVID-19 pandemic. in service by 2030 (See Fig. 6 ). A series of detailed technology road 6 J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11

According to a city development plan, Wuhan, capital city of central China’s Hubei Province, will build itself into a "Hydrogen City" through developing hydrogen energy industry [34] . It is reported that the city is to advance research and development of core technology of hydrogen production, storage and transport, and improve hydrogen infrastructure in the coming years. Grove Hy- drogen Automotive, named in honour of the fuel cell pioneer, is an upmarket automobile producer located in Wuhan.

4.3. In South Korea Fig. 6. China’s development goal for hydrogen refuelling stations (HRS) and fuel cell vehicles (FCV). Data from IPHE Country Update March 2017: China and Society of Automotive Engineers in China (VoodooDot/Shutterstock). In an announcement in January 2019, the Government of South Korea laid out an ambitious roadmap for a hydrogen society. Its stated goals are the production of 6.2 million fuel cell electric vehicles and also the construction of 1,200 refuelling stations across maps for fuel cell vehicles for China may also be found elsewhere the country by 2040 ( Fig. 7 ). Another projection is 630,0 0 0 hydro- [28] . gen fuel cell vehicles on the road by 2030. The plan is for hydrogen In 2018, to overcome the current gaps in the country’s know- to drive a new economic growth engine and turn South Korea into how and fuel cell infrastructure, China began to invest heavily a society fuelled by eco-friendly energy [35] . in foreign hydrogen fuel cell technology. Weichai Power, China’s Sales of the Hyundai Nexo fuel cell vehicle (FCV) passed the largest state-owned diesel engine manufacturer purchased 20 per- 1,0 0 0 mark in 2019 [36] and the company is also opening a se- cent stakes in fuel cell manufacturers Ballard Power Systems ries of hydrogen refuelling stations. Hyundai is also producing a (Canada) and Ceres Power (UK). Air Liquide signed an agree- heavy fuel cell powered truck for possible entry into the US mar- ment with Sichuan Houpu Excellent Hydrogen Energy Technology ket [37] . Daesan Green Energy is constructing one of the largest to build and market hydrogen-refuelling stations in China. Ceres hydrogen fuel cell power plants in the world, and is expected to Power are leaders in solid oxide fuel cell technology. This type of be operational in June 2020 [38] . More than $200 million has been fuel cell is highly efficient and stable, but, unfortunately, requires committed to the 50 MW plant, which will generate electricity for a high operating temperature. However, solid oxide fuel cells are 80,0 0 0 homes [ 39 , 40 ]. well suited for a variety of hydrogen- containing fuels for decen- It is interesting to note that despite energy independence being tralised power generation for homes, offices and other facilities a stated goal of the Government roadmap, that document also pro- such as data centres [29] . nounces that it seeks to “Establish overseas production base” [41] . China initially moved its Government subsidies from battery This appears to be linked with the policy of the Australian gov- electric vehicles to hydrogen fuel cell vehicles, but then announced ernment, which has a programme aimed at becoming as a global all subsidies will be withdrawn to eliminate a “subsidy culture” in supplier of hydrogen in the near future [ 42 , 43 ]. an attempt to promote competition. However, the decision to eliminate subsidies on New Energy Vehicles (to include battery electric and fuel cell vehicles) was reversed on 10 January 2020 [30] . 4.4. In the USA There is a partnership with Toyota, which will supply key fuel cell technology to China’s First Automobile Works (FAW Group), Throughout this paper, there are references to US activities in and Higer Bus. Both are major players in the truck and bus seg- many contexts such as the application of hydrogen fuel cells re- ment. Toyota is also setting up a research institute in Beijing in flecting societal changes (Box 1) to novel methods of hydrogen partnership with Tsinghua University to study car technology us- production (Section 5). Even though the George W. Bush initiative ing hydrogen power and other green technologies. stalled when many experts believed that a broader-based, nearer-

It took only a decade for China to build the world’s largest bat- term energy policy would mark a surer route to the same goals tery electric vehicle market. Now the architect behind that suc- of a low carbon energy future [44], there are now many ongoing cess, Wan Gang (Minister of Science and Technology, 2007–2018), activities, a selection of which are described below. wants to do the same for hydrogen-powered fuel cell electric vehi- As an example of fuel cell development for heavy haulage, the cles. The strategy is captured in a perceptive and strong statement Nikola Motor Company is reinventing trucking by replacing diesel

[31] made by Huang Libin, a spokesman for the Ministry of Indus- heavy-duty trucks with hydrogen fuel cell trucks. It is reported that try and Information Technology (MIIT): Anheuser-Busch has ordered hundreds of hydrogen trucks from Nikola. The deal, for “up to 800” trucks, is 20 times as big as the “Hydrogen fuel cell vehicles and pure electric vehicles with lithium one the beer distributor struck with Tesla [45] . batteries are important technical routes for new energy vehi- In another example [46] , a Toyota and Kenworth venture is de- cles. Pure electric vehicles are more suitable for urban and short- ploying 10 hydrogen fuel-cell semi- trucks at the Ports of Los An- distance passenger travel, while hydrogen fuel cells are more suit- geles and Long Beach in California. The project is being funded in able for long-distance and large commercial vehicles. We believe part by the California Air Resources Board. that hydrogen fuel cell vehicles and pure electric vehicles will co- Refuelling infrastructure is obviously a key issue for the uptake exist and complement each other for a long time to meet the needs of fuel cell vehicles (FCVs). The Fuel Cell Technologies Office (FCTO) of transportation and people’s travel. ” of the United States Department of Energy (DOE) reports that as of January 25, 2018, there are 39 publicly available hydrogen stations It is noteworthy that an unmanned aircraft powered by hy- for fuelling fuel cell vehicles (FCVs) in the United States –35 in drogen fuel finished 10 test flights, significant progress by its de- California, 2 in South Carolina, and 2 in the Northeast. Another 29 veloper, the Commercial Aircraft Corporation of China, in explor- public stations in California and 5 in the Northeast are planned ing new propulsion methods for aircraft [32] . Fuel cells are more [47] . suited as a means of power for aircraft flying at low altitudes since Examples of advanced projects include the following. In May the water exhaust has a potential deleterious effect at higher alti- 2019, NASA announced [48] support for a University of Illinois tudes [33] . (Urbana- Champaign) examination of the use of liquid hydrogen J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11 7

Fig. 7. Road map for the hydrogen economy in South Korea; hydrogen refuelling stations (HRS), fuel cell vehicles (FCV) and industrial and domestic fuel cell (FC) capacity. Data from 28th IPHE Steering Committee Meeting, Pyeong Chang, 2018 and Hankyoreh, January 20, 2019 (metamorworks/Shutterstock image). as fuel cells that generate electricity to propel an aircraft. The su- German companies are actively developing green hydrogen percooled liquid would be used to enable the highly eﬃcient su- technology and are collaborating with companies such as Royal perconducting electrical systems. Dutch Shell plc to bring production to commercial scale to develop Washington State University’s School of Mechanical and Materi- a national hydrogen infrastructure. There is also consideration of als Engineering has received a grant from the U.S. Army to demon- use of hydrogen mixtures in the gas grid and for large-scale indus- strate a liquid hydrogen-powered UAV and refuelling system. The trial processes such as steel making [57] . The incumbent technol- $7.2 million total grant includes researchers from Mississippi State ogy of steel production for the last 200 years leads to the contin-

University, Insitu Inc., and Navmar Applied Sciences Corporation. uous emission of copious amounts of CO2 . Germany has made sig- Insitu, a subsidiary of Boeing, will provide their ScanEagle3® UAV, nificant strides in converting steel production units that normally equipped with a fuel cell-powered electric engine [49]. liberate CO2 to those that liberate only water by using hydrogen It is apparent that these activities are clearly not part of a na- instead of carbon to reduce iron oxide [58-60] . We note also that tional programme as in the earlier George W. Bush initiative but the related Swedish project ‘Hybrit’ ( Hydrogen Breakthrough Iron- rather dispersed and initiated by regional and industry-led pro- making Technology ) is set to produce the ambitious target of so- grammes. A coalition of 19 companies including auto, truck, en- called “zero-carbon steel” from 2020 onwards also by using hydro- ergy, information systems and analytical support have an ambi- gen instead of carbon as the reactant in the reduction of iron ore to tious roadmap on how the US could lead in hydrogen technologies elemental iron [61] . Steel making is a forefront, excellent example [50] . where the use of hydrogen can lead to truly significant decarboni- The roadmap suggests nine actions, including decarbonisation sation in an otherwise highly carbon-intensive industrial process. goals, infrastructure development and reviewing energy sector reg- Up to 1500 radio tower (cellular telephone) sites in Germany ulations to ensure they account for hydrogen. could receive their emergency back-up power from hydrogen fuel Despite laudable activities within the US Department of En- cells. Operators have to ensure a minimum of 72 hours power au- ergy [51] , such as the injection of $40 million in August 2019 tonomy and fuel cells provide a reliable alternative to diesel gen- for a range of hydrogen-related projects [52] , it is unclear if a erators to provide power to critical infrastructure [62] . co-ordinated national strategywill be forthcoming to compete on the same scale as Japan and China. Furthermore, the crisis drivers of the past decades are not immediately apparent. In December 4.6. In the UK; a prediction is realised! 2018, the U.S. became a net oil exporter for first time in 75 years [53] and in August 2017, withdrew from the Paris Climate Accord There have been successful trials of hydrogen fuel cell buses [54] . Therefore, there might not be the same incentive to develop in London since 2003 [63] . These early Mercedes buses only had a “Hydrogen City” like Wuhan [34] . a range of 125 miles but the trials appeared to be successful so it is surprising that there has not been more activity in the area. There was an announcement in May 2019 that 20 double decker 4.5. In Germany fuel cell buses would be introduced to London although the company concerned, Wrightbus went into receivership but has now Germany approved its National Innovation Programme for Hy- (November 2019) been partially rescued. Since the transport sector drogen and Fuel Cell Technologies for a further ten years with EUR is responsible for the highest source of CO2 emissions (33%) in the 1.4 billion of funding, including subsidies for publicly accessible UK [64] , the introduction of fuel cell powered buses would make hydrogen refuelling stations and fuel cell vehicles, to be comple- a valuable contribution in reducing levels of emissions as well as mented by EUR 2 billion of private investment. Germany operates reducing the (recognised) toxicity of the city’s atmosphere. There the first commercial hydrogen-powered train and there is a large are examples of emergency service interest in fuel cell vehicles in annual increase in the number of refuelling stations, with an esti- London with the Metropolitan Police Service in London launching mated 100 by the end of 2019 [55] . a zero-emissions programme and has already started trialling 21 The German automobile industry is embracing hydrogen tech- hydrogen-powered cars [65] . nology through the development of fuel cell vehicles with the Audi There are also plans in the UK to create local regions where company leading this effort. Chairman Bram Schot has stated that there will be a strong emphasis on the use of hydrogen [66] and the reasons behind the move include continuing environmental also, intriguingly, to create methods of turning waste plastic into and humanitarian concerns over the necessary natural resources hydrogen [67] . From December 2020, over 600 homes and busi- for battery production (particularly lithium and cobalt) and doubts nesses in Gateshead UK will receive gas blended with 20% hydro- over electric cars being able to deliver on ever-more demanding gen in a demonstration lasting 10 months, as part of the UK Hy- customer requirements [56] . Deploy hydrogen blending programme [68] . 8 J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11

As far back as 2006, the Hydrogen Energy Group, part of The 80% by 2030 [77] . It is also estimated that if by 2030 the cost of Forum for Renewable Energy Development in Scotland published hydrogen generated from renewable energy falls below $2.20 per an ambitious vision for hydrogen [69] . There have been consid- Kg, it will be competitive to be used in steel making assuming a erable advances and it has indeed been suggested that “Scotland coking coal price of $310 per ton [78] . could have the first 100% hydrogen network in the world”. One major It should also be noted that if renewable energy, rather than achievement is HYSEAS III, a hydrogen fuel cell-powered ferry due electricity generation by burning coal is used for electrolysis, steam for delivery in 2020 for use around the Orkney archipelago [70]. methane reforming, which emits CO2 would still have a consider- The hydrogen will be produced locally by electrolysis using tidal ably lower environmental impact, being only about 3% that of elec- and wind power generation. It could indeed be argued that hydro- trolysis [79] . New catalysts are continually being developed in an gen production in Orkney, now self-sufficient in renewable electri- attempt to replace the use of scarce and expensive platinum in the cal power, is 300 years ahead of Haldane’s more general prediction hydrogen production processes [80] . from 1923 about a future UK hydrogen economy based on renew- Many years prior to current climate change concerns, it is par- able energy [71] . ticularly interesting to note as mentioned earlier that George W. Bush in his State of the Union address, highlighted not only the 5. The grand challenge of the large-scale production of clean use of nuclear (fission) generated electricity for electrolysis of wa- hydrogen ter, but also fusion power [17] as a means of generating clean (i.e.

CO2 -free) hydrogen. By far the largest current source of hydrogen, worldwide, origi- As is the case for New Zealand, Norway is rich in renewable nates from the steam reforming of natural gas and the partial ox- sources of energy thanks to its extensive network of hydroelec- idation of heavy hydrocarbons. Although highly effective and effi- tric schemes. In June 2019, the South Korean President Moon Jae- cient, the steam-reforming industrial process nevertheless entails a in signed a Memorandum of Understanding with Norway to co- significant liberation of CO2 . operate in the field of hydrogen energy so as to capitalise on South Producing cost-competitive, low-carbon - emission clean, Green Korea’s strength in hydrogen-powered vehicles and Norway’s abil- hydrogen in large volumes is without question the greatest barrier ity to produce and supply carbon- free hydrogen [81] . Norway has to developing a truly sustainable or renewable hydrogen energy so- a long history and experience of the use of electrolysis to produce ciety. It is recognized, worldwide, that the large-scale incorporation hydrogen for industrial purposes and recent work describes the de- of hydrogen in numerous technologies and hydrogen fuel cells will velopment of an electrolyzer for high-pressure steam using novel not reach fruition until it becomes possible – routinely –to gen- catalysts [82] . erate large quantities of high purity clean Green hydrogen through Nel Hydrogen (Oslo) is in collaboration with Nikola Motor Com- renewable energy routes with zero (or low) associated CO2 emis- pany (US) in the development of refuelling stations supplying hy- sions from the production process. Once Green hydrogen can be drogen generated locally by electrolysis using renewable sources. routinely produced in massive quantities, it will undoubtedly re- We note also a truly ambitious programme of 700 hydrogen filling place the hydrogen now produced by steam reforming of methane stations is planned for the US and Canada by 2028 [83] . [72] . Other routes to carbon-free, Green hydrogen production include Fuel cell electric vehicles running on hydrogen currently use pyrolysis and microwave-initiated catalytic dehydrogenation or filling stations, which deliver hydrogen at 70 MPa pressure. Very “hydrogen stripping” of hydrocarbons. A preliminary cost estimate few stations, worldwide, currently have hydrogen produced from of thermal catalytic pyrolysis –the decomposition of methane to renewable sources like solar energy. It is, however, encouraging hydrogen and solid carbon (thus, importantly - without CO2 liber- that photovoltaic installations during the past decade have seen a ation) –shows that the cost of producing hydrogen by this process significant increase and as pointed out by Eisenberg et al [2] that is approximately the same as that for steam reforming of methane price points per kWh have become competitive with electrical en- before the cost of sequestration of either CO2 or carbon is incor- ergy obtained from fossil fuels. It is important to note that this porated [84] . Since the cost (both in financial and energy terms) of situation has arisen because of the present day ability to produce capturing and sequestering (gaseous) CO2 is inevitably greater than photovoltaic grade silicon in large quantities –cheaply –in the that for solid, elemental carbon, the thermal decomposition pro- People’s Republic of China as a historical consequence of exten- cess should be less expensive and energy intensive than the steam- sive subsidies. Further advances in the general area of clean Green reforming process. Thus, it is much easier to sequester elemental hydrogen are eagerly anticipated and surely imminent. Dubai Elec- carbon as a stable solid than CO2 as a dilute gas or low tempera- tricity and Water Authority, Expo 2020 Dubai and Siemens are co- ture liquid. The resulting solid carbon produced is also viewed as operating on a joint project that will become the Middle East and a marketable product for application such as fillers [84] or carbon North Africa’s first solar-based hydrogen electrolysis facility [73] . nanotube materials. Of course, there will also be a carbon tax sav- In March 2019, an important agreement was signed between ing, as noted, when the product is sequestered as solid, rather than

New Zealand and Japan [74] . This entailed the involvement of the aerial carbon (CO2 ) through this interesting process. company Halcyon Power which engaged with the Canadian Hydro- A novel pyrolysis technique under investigation, yet to be scaled genics Corporation to install a 1.5 MW hydrogen production facility up, centres on the high temperature pyrolysis of methane, then at the Mokai geothermal power plant in New Zealand. This plant bubbling through a liquid metal (or liquid metal alloy) to allow will start operating in 2020, and it enables geothermal power to be the release of the hydrogen and collection of the solid carbon [85] . used to produce hydrogen by electrolysis of water. When this ini- The Russian company Gazprom have realised that their substan- tiative reaches steady state, there will be a hydrogen supply chain tial European market share is likely to decline without the promise from New Zealand to Japan. New Zealand has also issued a con- of a near zero-emissions fuel. The company has reported a low- sultation paper to use hydrogen as a means of storing some of its temperature plasma thermal methane pyrolysis process, currently renewable energy [75] . being trialled in Tomsk [86] . It should also be noted that consider- Even though electrolyzers have in the past been considered to able variations exist between European countries as to the max- be rather ineﬃcient, rapid progress is being made to make them imum allowable blend-level of hydrogen in the natural gas grid more eﬃcient and hence competitive with other hydrogen genera- e.g. 4% for Switzerland and 12% for the Netherlands, as a conse- tion technologies [76] . It is predicted that the cost to produce hy- quence of national regulatory processes. A more consistent regu- drogen by electrolysis using renewable sources could fall by up to latory framework would be required for a supranational gas grid. J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11 9

This has considerable infrastructure implications and it could be ture and one of the world’s growth markets; it will also provide a more viable to generate hydrogen at a more local level, perhaps by breeding ground for new science and technology, new innovations, electrolysis using renewable energy. new companies, products and employment. Another route to carbon-free hydrogen is the liberation of hydrogen, intriguingly, directly from fossil hydrocarbons themselves, including wax and even petroleum and diesel, using microwave- initiated catalytic dehydrogenation or hydrogen-stripping [87] . This Acknowledgements provides a capability of the on-demand, distributed generation of hydrogen thus reducing the taxing requirements for storage and We are grateful to the following for interesting and construc- transportation of hydrogen either as high-pressure gas or liquid. tive discussions: Professor Harry Gray, Division of Chemistry and This technique might also be applicable to generate hydrogen from Chemical Engineering and the Beckman Institute, California In- other sources such as biomass and lignite and might be another stitute of Technology, Stuart McKay, Energy Team, Scottish Gov- greener route to exploit large lignite deposits such as those found ernment and Alun Rhydderch, Roads and Transport Authority of in Australia. There are several claims that aluminium-based pow- Dubai, UAE, Dr Tiancun Xiao, Dr Benzhen Yao and Professor Jon ders which react with water or any water-based liquid to pro- Dilworth, University of Oxford and Professor Hamid Almegren of duce on-demand hydrogen for power generation without a catalyst KACST, Riyadh, Saudi Arabia. [ 88 , 89 ]. Similar claims are made of silicon [90] and other materi- We are also grateful to Professor Yasuhiro Iwasawa, The Univer- als. General Atomics have been awarded a two year contract from sity of Electro-Communications, Ch ofu,¯ Tokyo and James Hinkley, the US Army do demonstrate a hydrogen on-demand system us- Victoria University of Wellington, New Zealand for drawing our at- ing the company’s aluminium alloy hydrogen generation technol- tention to the roadmap for Japan ( Fig. 5 ) and other data and to ogy [91] . Russian workers have demonstrated similar devices for Katsumi Yokomoto, NEDO, for permitting us to use the image. Pe- application such as chargers for mobile devices [92] . If this tech- ter P. Edwards thanks KACST and EPSRC for continued support. We nology is demonstrated to be viable, this could be transformative are indebted to Linda Webb for her support and professionalism in since it vastly reduces infrastructure requirements for the storage all stages of the preparation of this paper. and transport of hydrogen. Hydrogen may be considered as an “indirect” greenhouse gas since it reacts with the hydroxyl (OH) radical, normally a sink for methane –a potent greenhouse gas [33] . The effect of the loss of Conﬂict of Interest hydrogen through leaks and its potential deleterious environmental effects by reacting with other gases in the atmosphere there- The Authors declare that there is no conﬂict of interest. fore need to be minimised. The Japanese Agency New Energy and Industrial Development Organization (NEDO) is pursuing the development of polymer materials for gas seals and dispensing hoses and improved steels, including stainless steel for hydrogen contain- Appendix I ment. The recent discovery of natural hydrogen, for instance in Mali Recent Advances –Post submission [93] , provides another potential source of hydrogen in the longer An infographic has recently been published since submission term. This fascinating natural phenomenon has been little explored of this paper illustrating the dynamic landscape of hydrogen tech- and considerable research and development would require for ex- nologies to include activities in countries not discussed in this pa- ploration and exploitation of these hydrogen reserves, in much the per [95] . same way as it took a century for a similar development process The availability of low-carbon – green –hydrogen produced for petroleum. economically, sustainably at scale is key to the utilisation of hydrogen. Recent examples include:

6. Concluding remarks EDF are planning to generate hydrogen as part of the UK nuclear power update programme [96] .

The perceived role of hydrogen energy technologies and hydro- Recent work from the US describes research on a novel elec- gen fuel cells in the global energy system has undergone many vi- trolysis method using an alkaline anion exchange membrane (AEM) cissitudes. Excessive early expectations, followed by (perhaps an- and low cost catalysts such as nickel and iron [97]. Other studies ticipated) disillusion, the lack of both policy stability and a long have investigated the electrolysis of low-grade and saline surface term government view have all had their roles in inﬂuencing opin- water, an important considerations in area where water is a scarce ions about the viability of hydrogen technologies and hydrogen resource [98]. fuel cells, as have been cogently described by Stafell et al [94] . Hydrogen storage is an important support technology. Liquid or-

What is indisputable is that the general public is now urgently ganic hydrogen carrier (LOHC) technology is being developed in demanding replacement –even abandonment –of fossil fuels and South Korea as an alternative to compression storage [99]. introduction of renewable non-threatening alternative fuels that can secure the much desired low and ultimately zero-carbon sce- nario worldwide. Indeed “zero-carbon” has become a shibboleth by References certain groups as a ready identiﬁer of a socio-political stance. In summary, it is our view that hydrogen from renewable en- [1] G. Crabtree , Science 6464 (2019) 422–424 . ergy sources can surely be considered as the progenitor of the ul- [2] R. Eisenberg, H.B. Gray, G.W. Crabtree, PNAS ﬁrst published October 7, timate clean and climate-neutral energy systems. 2019. https://doi.org/10.1073/pnas.1821674116 (26 November 2019, date last accessed).

We have endeavoured to demonstrate, by speciﬁc examples, [3] Fuel cell fork lift trucks drive hydrogen into the future. FuelCellsWorks, Octo- that hydrogen technologies and hydrogen fuel cells, in its vari- ber 28, 2019 https://fuelcellsworks.com/news/fuel- cell- forklift- trucks- drive- ous manifestations across the world, are now beginning to play a hydrogen-into-the-future/ (18 November 2019, date last accessed) [4] Why Amazon Invested in Plug Power (AMZN, PLUG). Investopedia, June 25, key role in the path towards a low-carbon future. Hydrogen en- 2019 https://www.investopedia.com/news/why- amazon- invested- plug- power- ergy technology is a key to a sustainable and renewable energy fu- amzn-plug/ (18 November 2019, date last accessed) 10 J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11

[5] Amazon acquires right to buy stake in fuel cell maker Plug Power [32] Hydrogen fuel test plane completes flights. China Daily, March 19, 2019 http: Reuters Technology News, April 5, 2017 https://www.reuters.com/ //www.chinadaily.com.cn/a/201903/19/WS5c90b2c5a3106c65c34ef7c1.html (18 article/us- amazon- com- plug- power/amazon- acquires- right- to- buy- stake- November 2019, date last accessed) in- fuel- cell- maker- plug- power- idUSKBN1771BB (18 November 2019, date last [33] T.K. Tromp , R.L Shia , M. Allen , J.M. Eiler , Y.L. Yung , Science 30 0 (20 03) accessed) 1740–1742 . [6] Amazon Prime Air, Wikipedia, https://en.wikipedia.org/wiki/Amazon _Prime _ [34] "Hydrogen City" to be built in Central China. XinhuaNet, January 21, 2018 Air (16 December2019, date last accessed) http://www.xinhuanet.com/english/2018-01/21/c _ 136913339.htm (18 Novem- [7] Ballard Blog, Hydrogen Powered Drones —Are They Ready to De- ber 2019, date last accessed) liver Your Packages? October 31, 2019 https://blog.ballard.com/hydrogen- [35] South Korean government announces roadmap for hydrogen economy, powered-drones (16 November 2019, date last accessed) Hankyoreh (January 20, 2019) http://english.hani.co.kr/arti/english _ edition/e _ [8] W.R. Grove , On a new voltaic combination, Philosophical Magazine and Journal business/879097.html . (18 November 2019, date last accessed) . of Science 13 (1838) 430–431 . [36] Sales of Hyundai hydrogen fuel cell Nexo pass 1K unit mark in 2019, [9] J.M. Thomas , Philosophical Magazine 92 (2012) 3757–3765 . Green Car Congress (May 21, 2019) https://www.greencarcongress.com/2019/ [10] US Department of Energy Comparison of Fuel Cell Technologies, Febru- 05/20190521-nexo.html . (18 November 2019, date last accessed) . ary 2011 https://www1.eere.energy.gov/hydrogenandfuelcells/fuelcells/pdfs/fc _ [37] Hyundai Debuts Dope Hydrogen-Powered Semi-Truck Concept. Mo- comparison _chart.pdf (18 November 2019, date last accessed) tor1.com, October 28, 2019 https://www.motor1.com/news/379027/ [11] L. Mond , C. Langer , Proceedings of the Royal Society of London 46 (1889) hyundai-hydrogen-semi-truck-concept/ (18 November 2019, date last ac- 296–304 . cessed) [12] W. Ostwald , Zeitschrift für Elektrotechnik und Elektrochemie 4 (1894) [38] Jung Min-hee, Hanwha Energy to Build World’s First ‘Zero-Fine Dust’ Electric 122–125 . Power Station, Business Korea, August 17, 2018 http://www.businesskorea.co. [13] K.R. Williams, Francis Thomas Bacon, 21 December 1904 –24 May 1992, Bio- kr/news/articleView.html?idxno=24387 (16 December 2019, date last accessed) graphical Memoirs of Fellows of the Royal Society 39 (1994) 2–9, doi: 10.1098/ [39] World’s largest fuel-cell power plant construction initiated in rsbm.1994.0 0 01 . South Korea. Hydrogen Digest Daily, August 12, 2019 http://www. [14] F.T. Bacon , Nature 186 (1960) 589–592 . biofuelsdigest.com/hydrogen/2019/08/12/worlds-largest- fuel- cell- power- [15] Advantages and Disadvantages of Hydrogen Fuel Cells https://futureofworking. plant- construction- initiated- in- south- korea/ (18 November 2019, date last com/10- advantages- and- disadvantages- of- hydrogen- fuel- cells/ (18 November accessed) 2019, date last accessed) [40] World’s largest fuel cell power plant located south of Seoul. https://www. [16] Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel, Bloomberg youtube.com/watch?v=maHewUTMuE0 (18 November 2019, date last accessed) (6 December 2019) https://www.bloomberg.com/news/articles/2019- 12- 06/ [41] Korean Government Announces Roadmap to Become the World Leader in the rolls-royce-pitches-nuclear-reactors-as-key-to-clean-jet-fuel . (09 December Hydrogen Economy, FuelCellsWorks (January 17, 2019) https://fuelcellsworks. 2019, date last accessed) . com/news/korean-government- announces- roadmap- to- become- the- [17] President George W Bush, State of the Union Address, January 28, 2003, White world- leader- in- the- hydrogen-economy/ . (18 November 2019, date last House https://georgewbush-whitehouse.archives.gov/infocus/technology/ accessed) . economic _policy200404/chap2.html (18 November 2019, date last accessed) [42] Australia calls for S. Korea’s cooperation on hydrogen economy, YonHap News [18] GM Hydrogen Fuel Cell Vehicles, GM Heritage Center https://www. Agency (March 12, 2019) https://en.yna.co.kr/view/AEN20190312011100320 . gmheritagecenter.com/featured/Fuel _Cell _Vehicles.html (18 November 2019, (18 November 2019, date last accessed) . date last accessed) [43] Australian Hydrogen Strategy Updates, Australian Government, Depart- [19] S.A . Wells, A . Sartbaeva, V.L. Kuznetsov, P.P. Edwards, Encyclopedia of In- ment of Industry, Innovation & Science https://www.industry.gov.au/ organic and Bioinorganic Chemistry, John Wiley & Sons, Ltd, 2011, pp. 1– data- and- publications/australian- hydrogen-strategy-updates (18 November 24. https://doi.org/(18 November 2019, date last accessed), doi: 10.1002/ 2019, date last accessed) 9781119951438.eibc0452 . [44] R.F. Service, Science 305 (5686) (August 12, 2004) 958–961, doi: 10.1126/ [20] , in: Hydrogen Development in Japan, Report from British Embassy, Tokyo, Jan- science.305.5686.958 . uary 2002 . [45] Anheuser-Busch orders hundreds of hydrogen trucks from zero-emission [21] The Fuel Cell and Hydrogen Energy Association (FCHEA), Japan Fuel Cell startup Nikola The Verge, May 3, 2018, https://www.theverge.com/2018/5/3/ Developments, March 11, 2019. http://www.fchea.org/in-transition/2019/3/11/ 17314606/anheuser- busch- budweiser- hydrogen- trucks- zero- emission- startup- japan- fuel- cell- developments (18 November 2019, date last accessed) nikola (27 December 2019, date last accessed) [22] Japan is building a Hydrogen Society. Innovator’s Magazine, July 31, 2018 https: [46] Hydrogen-Powered Kenworth Semi Trucks are Being Deployed in Los An- //www.innovatorsmag.com/japan- is- building- a- hydrogen- society/ (18 Novem- geles and Long Beach, The Drive (April 23, 2019) https://www.thedrive. ber 2019, date last accessed) com/tech/27606/hydrogen-powered-kenworth-semi-trucks-are-being- [23] Hydrogen fuel network to establish Fukushima as Japan’s Center for renewable deployed- at- los- angeles- long- beach- ports . (27 December 2019, date last energy, Energy Storage World Forum https://energystorageforum.com/news/ accessed) . hydrogen- fuel- network- establish- fukushima- japans- center- renewable-energy [47] Fact of the Month #18-01, Fuel Cell Technologies Office (FCTO), US De- (18 November 2019, date last accessed) partment of Energy, January 29, 2018 https://www.energy.gov/eere/fuelcells/ [24] I. Shigeki , K. Sakata , Clean Energy 3 (2019) 105–113 . fact- month- 18- 01- january- 29- there- are- 39- publicly- available- hydrogen- fueling- [25] World’s First Liquefied Hydrogen Carrier Suiso Frontier Launches Building an stations (27 December 2019, date last accessed) International Hydrogen Energy Supply Chain Aimed at Carbon-free Society, [48] NASA Aeronautics Selects Three University Teams for Research Kawasaki announcement (6 December 2019) https://global.kawasaki.com/en/ Help. May 8, 2019 https://www.nasa.gov/aero/nasa-aeronautics- corp/newsroom/news/detail/?f=20191211 _ 3487 . (27 December 2019, date last selects- three- university- teams- for- research- help/ (27 December 2019, date accessed) . last accessed) [26] Is hydrogen the next “clean coal”? The Australia Institute discussion paper, [49] US Army Grant Supports Development of Hydrogen-Powered Unmanned October 2019 https://www.tai.org.au/sites/default/files/P725%20Japan%20Aus% Aerial Vehicle FuelCellsWorks, July 18, 2019 https://fuelcellsworks.com/news/ 20hydrogen%20report%20%5BFINAL%5D.pdf (27 December 2019, date last ac- us- army- grant- supports- development- of- hydrogen- powered- unmanned- cessed) aerial-vehicle/ (27 December 2019, date last accessed) [27] Kawasaki launches the world’s first liquid hydrogen transport ship, New Atlas, [50] Road Map to a US Hydrogen Economy, The Fuel Cell and Hydrogen Energy As- 15December 2019 https://newatlas.com/marine/kawasaki- worlds- first- liquid- sociation (FCHEA) November 6, 2019 https://www.greencarcongress.com/2020/ hydrogen- transport- ship/ (27 December 2019, date last accessed) 03/20200322-h2map.html (23 March 2020, date last accessed) [28] Development potential of hydrogen fuel cell electric vehicles in China Ayako [51] 2019 Annual Merit Review and Peer Evaluation Report https://www.hydrogen. Matsumoto Industry Innovation Dept., Technology & Innovation Studies Div. energy.gov/annual _ review19 _report.html (27 December 2019, date last ac- Mitsui & Co. Global Strategic Studies Institute, Mitsui & Co. Global Strategic cessed) Studies Institute Monthly Report, March 2019 https://www.mitsui.com/mgssi/ [52] Department of Energy Announces $40 Million in Funding for 29 Projects en/report/detail/ __ icsFiles/afieldfile/2019/05/17/1903 _ matsumoto _e.pdf Data to Advance H2@Scale. US Department of Energy, August 15, 2019 from Society of Automotive Engineers of China. (18 November 2019, date last https://www.energy.gov/articles/department- energy- announces- 40- million- accessed) funding- 29- projects- advance- h2scale (27 December 2019, date last accessed) [29] Ceres: Our SteelCell® Technology https://www.cerespower.com/work- [53] U.S. Becomes Net Oil Exporter for First Time in 75 Years. Oil- with- our- steelcell/our- steelcell- technology/ (18 November 2019, date last Price.com, December 6, 2018 https://oilprice.com/Energy/Crude-Oil/ accessed) US- Becomes- Net- Oil- Exporter- For- First- Time- In- 75- Years.html# (27 De- [30] More Great News For Tesla China — MIIT Minister States No Cut In EV cember 2019, date last accessed) Subsidies In July Clean Technica, January 11, 2020 https://cleantechnica. [54] US Notifies UN of Paris Climate Deal Pullout. BBC News, 5 August 2017 https: com/2020/01/11/more-great-news-for-tesla-china-miit-minister-states- //www.bbc.co.uk/news/world- us- canada- 40829987 (27 December 2019, date no- cut- in- ev- subsidies- in- july/?utm _source=marfeelpush (13 January 2020, last accessed) date last accessed) [55] The Future of Hydrogen, Report prepared by the IEA for the G20, Japan, June [31] China to Support Hydrogen and Fuel Cell Vehicles to Go Green. Fuel- 2019 Table 1. Selected hydrogen-related government announcements since CellsWorks, 23 April 2019 https://fuelcellsworks.com/news/china-to-support- early 2018 https://www.iea.org/hydrogen2019/ (18 November 2019, date last hydrogen- and- fuel- cell- vehicles- to- go- green (18 November 2019, date last ac- accessed) cessed) J.M. Thomas, P.P. Edwards and P.J. Dobson et al. / Journal of Energy Chemistry 0 0 0 (2020) 1–11 11

[56] Audi renews hydrogen powertrain development scheme, Autocar (3 May [76] G. Glenk , S. Reichelstein , Nat. Energy 4 (2019) 216–222 . 2019) https://www.autocar.co.uk/car-news/industry/audi-renews-hydrogen- [77] Hydrogen’s Plunging Price Boosts Role as Climate Solution, Bloomberg powertrain- development- scheme . (18 November 2019, date last accessed) . (August 22, 2019) https://www.bloomberg.com/news/articles/2019- 08- 21/ [57] Momentum for green hydrogen picking up in Europe, Renewable Energy cost- of- hydrogen-from-renewables-to-plummet-next-decade-bnef . World, 18 November 2019 https://www.renewableenergyworld.com/2019/ [78] How Hydrogen Could Solve Steel’s Climate Test and Hobble 11/18/momentum- for- green- hydrogen- picking- up- in- europe/?utm _ medium= Coal, Bloomberg, September 2, 2019 https://about.bnef.com/blog/ email&utm _campaign=rew _weekly _newsletter&utm _ source=enl&utm _content= hydrogen-solve-steels-climate-test-hobble-coal/ (07 December 2019, date 2019- 11- 20&eid=291109941&bid=2562284 (18 November 2019, date last last accessed) accessed) [79] Y. Chen , X. Hu , J. Liu , Energies 12 (2019) 3031 . [58] G. Deerberg , M. Oles , R. Schlögl , Chemie Ingenieur Technik 90 (2018) [80] Storing energy in hydrogen 20 times more effective using platinum-nickel 1365–1368 . catalyst, FuelCell Works (November 16, 2019) https://fuelcellsworks.com/news/ [59] R. Schlögl , Chemie Ingenieur Technik 90 (2018) 1369–1373 . storing-energy-in-hydrogen-20-times-more-effective-using-platinum-nickel- [60] T. Wich, W. Lüke, K. Büker, O von Morstein, R. Kleinschmit, M. Oles, R. Achatz, catalyst/ . (18 November 2019, date last accessed) . Chemie Ingenieur Technik (2018) 1369–1373 October 2018 https://doi.org/10. [81] Korea, Norway to cooperate on hydrogen, shipbuilding. The Korea Herald, June 10 02/cite.20180 0 067 . (20 January 2020, date last accessed) . 13, 2019 http://www.koreaherald.com/view.php?ud=201906130 0 0650 [61] How hydrogen could change the face of steel production as we know [82] E. Vøllestad , R. Strandbakke , M. Tarach , D. Catalán-Martínez , M-L. Fontaine , it. en:former, May 29, 2019 https://www.en-former.com/en/hydrogen- D. Beeaff, D.R. Clark , J.M. Serra , T. Norby , Nature Materials 18 (2019) 752–759 . revolution- steel- production/?fbclid=IwAR2c3T62F _j- vJ8jNgfuRGjSMHLQHfilm [83] Nikola Motor Company, Press Release (November 5, 2018) https://nikolamotor. WcP-2sptxkyu4UU69C0sIzCslU (18 November 2019, date last accessed) com/press _releases/nikola-launches-stunning-truck-for-european-market-53 . [62] Hydrogen fuel cells to provide back-up power for German radio tower (18 November 2019, date last accessed) . sites, H2-View, 27 November 2019 https://www.h2-view.com/story/ [84] M. Steinberg , Intern. J. Hydrogen Energy 24 (1999) 771–777 . hydrogen- fuel- cells- to- provide- back- up- power- for- german- radio- tower- sites/ [85] T. Geißler , A. Abánades , A. Heinzel , K. Mehravaran , G. Müller , R.K. Rathnam , (07 December 2019, date last accessed) C. Rubbia , D. Salmieri , L. Stoppel , S. Stückrad , A. Weisenburger , H. Wenninger , [63] 20 fuel cell double decker buses will run in London, Sustainable Bus, 2019 Th Wetzel , Chem. Eng. J 299 (2016) 192–200 . https://www.sustainable- bus.com/news/20- fuel- cell- double- decker- buses- [86] Russia Looks to Hydrogen as Way to Make Gas Greener for Europe, Bloomberg will- run- in- london/ (18 November 2019, date last accessed) (November 8, 2018) https://www.bloomberg.com/news/articles/2018- 11- 08/ [64] Department for Business, Energy & Industrial Strategy, 2018 UK Green- russia- looks- to- hydrogen- as- way- to- make- gas- greener- for- europe . (18 house Gas Emissions, Provisional Figures, Statistical Release: Na- November 2019, date last accessed) . tional Statistics, 28 March 2019, p.6 https://assets.publishing.service. [87] S. Gonzalez-Cortes , D.R. Slocombe , T. Xiao , A. Aldawsari , B. Yao , V.L. Kuznetsov , gov.uk/government/uploads/system/uploads/attachment _ data/file/790626/ E. Liberti , A.I. Kirkland AI , M.S. Alkinani MS , H.A. Al-Megren , J.M. Thomas , 2018- provisional- emissions- statistics-report.pdf (18 November 2019, date last P.P. Edwards , Sci. Rep. 6 (2016) 35315 . accessed) [88] Army Hydrogen Generation Discovery may spur New Industry US Army Re- [65] Met Police trials hydrogen cars as it launches 2050 zero-carbon goal, IET search Laboratory, July 16 2019 https://www.arl.army.mil/www/default.cfm? Engineering & Technology (October 9, 2019) https://eandt.theiet.org/content/ article=3479 (18 November 2019, date last accessed) articles/2019/10/met- police- trials- hydrogen- cars- as- it- launches- 2050- zero- [89] Composition for Generating Hydrogen World Intellectual Property Organisation carbon-goal/ . (18 November 2019, date last accessed) . WO 2019/137743 [66] The North West of England has the industry, infrastructure and innovation to [90] Composition for Generating Hydrogen US Patent Application, US make hydrogen energy a reality, North West Hydrogen Alliance http://www. 2015/0266729A1 nwhydrogenalliance.co.uk/ (18 November 2019, date last accessed) [91] General Atomics Awarded Army Contract for Hydrogen Generation System [67] Peel announces plans for UK’s first plastic waste to hydrogen facility at Prototype FuelCellWorks, November 8, 2019 https://fuelcellsworks.com/news/ Cheshire site, BusinessLive, 14 August 2019 https://www.business-live.co.uk/ general-atomics-awarded-army-contract-for-hydrogen-generation-system- manufacturing/peel- announces- plans- uks- first- 16746723 (18 November 2019, prototype/ (18 November 2019, date last accessed) date last accessed) [92] Russia: Potential next generation of portable hydrogen fuel cells tested in [68] T. Isaac, Clean Energy 3 (2019) 114–125 https://doi.org/10.1093/ce/zkz006 . (23 Moscow https://www.youtube.com/watch?v=woZRHX8Mm5Y (18 November November 2019, date last accessed) . 2019, date last accessed) [69] Hydrogen and Fuel Cell Opportunities for Scotland, The Hydrogen En- [93] A. Prinzhofer , Cissé C.S.T , A.B. Diallo , Inter. J. Hydrogen Energy 43 (2018) ergy Group Report Scottish Executive (August, 2006) https://www2.gov.scot/ 19315–19326 . resource/doc/146634/0038379.pdf . (18 November 2019, date last accessed) . [94] I. Staffell , D. Scamman , A. Velazquez Abad , P. Balcombe , P.E. Dodds , P Ekins , [70] HYSEAS III – The World’s First Hydrogen Powered Sea-Going Car N. Shahd , K.R. WardaI , Energ. Environ. Sci. 12 (2019) 463–491 . Ferry 1 Scottish Hydrogen & Fuel Cell Association, June 18, 2018 [95] Where In The World Are The Hydrogen Trailblazers? [Infographic], Forbes, http://www.shfca.org.uk/news/2018/6/18/hyseas- iii- the- worlds- first- 11 March 2020 https://www.forbes.com/sites/mitsubishiheavyindustries/ hydrogen-powered-sea-going-car-ferry-destination-orkney (18 November 2020/03/11/where- in- the- world- are- the- hydrogen- trailblazers- infographic/ 2019, date last accessed) #1153e88378f8 (14 March 2020, date last accessed) [71] J.B.S. Haldane, On the future of energy (1923). Daedalus; or, Sci- [96] EDF plans vast hydrogen production at UK nuclear plants, ence and the Future (1924), E. P. Dutton and Company, Inc., a paper Recharge, 26 February 2020 https://www.rechargenews.com/transition/ read to the Heretics, Cambridge, on 4 February 1923. Second edition edf- plans- vast- hydrogen-production-at-uk-nuclear-plants/2-1-763048 (11 (1928), London: Kegan Paul, Trench & Co. https://www.thegwpf.com/ March 2020, date last accessed) jbs- haldane- 1923- on- the- future- of- energy/ (18 November 2019, date last [97] D. Li, E.J. Park, W. Zhu, Y Zhou Q.Shi, H. Tian, Y. Lin, A. Serov, B. Zulevi, accessed) E.D. Baca, C. Fujimoto, H.T. Chung, Y.S. Kim, Nature Energy (2020) https://doi. [72] P.P Edwards , V.L. Kuznetsov , W.I.F David , Philosophical Transaction of the Royal org/10.1038/s41560- 020- 0577- x . (14 March 2020, date last accessed) . Society of London A 365 (2007) 1043–1056 . [98] W. Tong, M. Forster, F. Dionigi, S. Dresp, R.S. Erami, P. Strasser, [73] DEWA and Siemens start work on solar-powered hydrogen produc- A.J. Cowan, P. Farràs, Nature Energy (2020) https://doi.org/, doi: 10.1038/ tion facility. PVTech, February 4, 2019 https://www.pv-tech.org/news/ s41560- 020- 0550- 8 . dewa- and- siemens- start- work- on- solar- powered- hydrogen- production- facility [99] KEPO develops Korea’s first hydrogen storage liquid technology, Fuel- (18 November 2019, date last accessed) CellWorks, March 10, 2020 https://fuelcellsworks.com/news/kepco-develops- [74] Hydrogen production facility to be set up at geothermal plant in New koreas- first- hydrogen- storage- liquid- technology/ (13 March 2020, date last ac- Zealand. Think GeoEnergy, April 9, 2019 http://www.thinkgeoenergy.com/ cessed) hydrogen-production-facility-to-be-set-up-at-geothermal-plant-in-new-zealand/ (18 November 2019, date last accessed) [75] Can New Zealand really lead the world in green hydrogen? The SpinOff (September 5, 2019) https://thespinoff.co.nz/business/05- 09- 2019/ can- new- zealand- really- lead- the- world- in- green- hydrogen/ . (18 November 2019, date last accessed) .