S. Harish, M.Sc
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Exploration of synthetic routes for nano-structured materials: Their applications in catalysis Thesis submitted to BHARATHIDASAN UNIVERSITY for the award of the degree of DOCTOR OF PHILOSOPHY IN CHEMISTRY by S. Harish, M.Sc (Ref. No: 38344/Ph.D.1./Chemistry/F.T/April 2009) ELECTRODICS AND ELECTROCATALYSIS DIVISION CSIR-CENTRAL ELECTROCHEMICAL RESEARCH INSTITUTE KARAIKUDI - 630 006, INDIA (January, 2013) DECLARATION I, Mr S. Harish, hereby declare that the thesis entitled “Exploration of synthetic routes for nano-structured materials: Their applications in catalysis” has been originally carried out by me at Central Electrochemical Research Institute (CSIR–CECRI), Karaikudi, India under the guidance of Dr James Joseph, Principal Scientist, CSIR–CECRI, Karaikudi, India. The content of this thesis or part thereof has not been submitted to any other university or institute for the award of any Degree, Diploma or other similar title. Place: Karaikudi (S. Harish) Date: i CERTIFICATE This is to certify that the thesis entitled “Exploration of synthetic routes for nano- structured materials: Their applications in catalysis” submitted by Mr. S. Harish is a bonafide record of research work done by him for the degree of Doctor of Philosophy under my guidance at CSIR-Central Electrochemical Research Institute (CSIR-CECRI), Karaikudi, India. The content of this thesis or part thereof has not been submitted to any other university or institute for the award of any Degree, Diploma or other similar title. Place: Karaikudi (Dr James Joseph) Date: Research Supervisor ii ACKNOWLEDGEMENTS I wish to express my sincere gratitude to many people who brought my dream of successfully completing this thesis. During this period, I have enjoyed my journey in research and learned from each and every individual whomever I met. I would like to thank my mentor Dr James Joseph, for giving me the opportunity to work on a challenging and interesting research project. My doctoral study would have been very difficult without his intelligent guidance, motivation and constant encouragement. I am grateful to Prof. C. Coutanceau for providing me an opportunity to work in his group at University of Poitiers, France for about six months. I appreciate his constant support during that period. Special thanks to Prof. S. Baranton for helping me in all the experiments during my stay. I also thank my lab mates in Poitiers, France for their scientific discussions and assistance in my research. It was a great experience and memorable days in my research career. I express my sincere thanks to Prof. A. K. Shukla and Dr V. Yegnaraman, former Directors of CSIR-CECRI and also to Dr. Vijayamohanan K. Pillai, Director of CSIR-CECRI for their encouragement, motivation and providing all the necessary facilities required for my research work. I wish to thank Dr K. L. N. Phani, with whom I have started my research career and it is his strong motivation, encouragement and realization of excitement in research every now and then helped me to enroll for Ph.D. My special thanks to Dr J. Mathiyarasu who helped me in different aspects from the date I entered CSIR-CECRI. His constant scientific as well as personal support helped me to join and pursue the doctoral work. I would like to thank Dr A. Ilangovan, Bharthidasan University, Trichy and Dr G. Chandramohan, A. V. V. M. Pushpam college, Poondi who are my doctoral committee members, for illuminating discussions, constant support and encouragement. I am thankful to Dr N. Kalaiselvi and Dr A. S. Prakash for their help in carrying out some experiments related to Li ion battery for my materials and the corresponding scientific discussions. iii My heartfelt thanks are due to Dr C. Sivakumar, Dr S. Senthil kumar and Dr V. Ganesh, Scientists of EEC Division for their friendship and scientific discussions. I am also extending my sincere thanks to all the EEC Division members and my lab mates Mr. C. Jeyabharathi, Mr. T. Nareshkumar, Mr. S. Boopathi, Mr. S. Anandhakumar, Mr. A. V. Narendrakumar, Ms A. Ananthi, Mr. P. Esakki Karthik, Mr I. Maheswaran, Mr T.V. Vineesh, Mr N. Sreekanth, Ms K. Dhanalakshmi and Ms T. Sowmya who have helped me in all possible ways during my research work. Above all, it is my duty to pay sincere thanks to my parents who had not only encouraged me and allowed me to stay away from the home for a longer time which helped me to pursue my research without any hesitation. Importantly, I show my gratitude to almighty for giving a sound health to my parents and also to me. I am also very thankful to all my relatives for their moral support and encouragement throughout. I express sincere thanks to my lecturers Dr K. Subramani and Dr K. Prem Nazir of Islamiah College, Vaniyambadi for their motivation and encouragement. I take this opportunity to thank my good friends Mr. M. S. Chandrasekar, Dr S. Prakash, Mr. K. Firoz Babu, Mr. Gangulibabu, Mr. R. Ravikumar and Dr K. Sundaram for staying with me closely not only during the happy moments but also whenever I am sad, down from my performance and in necessitate time. I also extend heartfelt thanks to all my friends of CSIR- CECRI. Financial support received from the prestigious agencies like Council of Scientific and Industrial Research (CSIR), Department of Science and Technology (DST) and French Embassy in India is greatly acknowledged. It is impossible to thank each and everyone who directly or indirectly helped me during my research career and hence I would like to place a record of gratitude to all those people. (S.Harish) iv Abstract In this thesis, novel synthetic routes in the preparation of nanostrucutred materials and their application in catalysis were explored. Nanostructured materials were synthesized using sol-gel, microwave activation and solid state decomposition methods. These materials were characterized using microscopy, spectroscopy and electrochemical techniques. Sol-gel method was followed to synthesize Au, Ag and AuAg alloy nano sols and their role on catalytic activity in chemical reduction of 4-nitrophenol was explored. Microwave assisted polyol method was studied for synthesize of carbon supported Pt, Ru and PtRu alloy nanoparticles and their electro- catalytic activity towards methanol oxidation. In-situ FT-IR technique was used to explain the mechanism of methanol oxidation. Solid state decomposition of Co 3[Co(CN) 6]2 was investigated to synthesize phase pure Co 3O4 and possible use of Co 3O4 as an anode material in Li ion battery was studied. The interaction between chloro metalates (of Au, Pt, Pd) and cyano metalates (of Fe, Ru) were investigated and this interaction was found to be a key step in the preparation of carbon supported alloy nanoparticles. Cyanogel processing in presence of carbon followed by thermal decomposition was exploited for the formation of carbon supported bimetallic alloy. Carbon supported bimetallic alloys were used as an electrocatalyst in methanol oxidation and oxygen reduction reactions. v ஆV4Kக இத ஆவறிைகயி, மாNபட Gைறயிைன பயப:தி மீ@ அைமEைடய நாேனா ெபாKக தயாZத மN அெபாKகளி விைனJ0 திறக பறி விவZகப: ள>. இெபாKக , கைரச-களி, மீஒலி ஊ0விE மN திம-நிைல சிைதV ேபாற Gைறகைள பயப:தி தயாZகப:, அவறி தைமக அதிநவ ீன எெலரா @ேணாகி, நிறமாைலமானி, மிப0பாV கKவிக ெகா: ஆராயபடன. Au , Ag உேலாக மN Au-Ag உேலாககலைவ நாேனா >க க , கைரச-களி Gைறயி தயாZகப:, அைவக 4- ைநேராஃபீனா ஆசிஜ-ஒ:க விைனJகியாக எ"வித பயப:கிற> எப> ஆராயபட>. காப ேமபரபி நிைலப:தபட Pt, Ru உேலாக மN Pt-Ru உேலாககலைவ நாேனா >க க மீஒலி >ைணெகா: பாலி-ஆகஹா Gைறயி தயாZகப:, அைவக ெமதனா மி-ஆசிஜேநற விைனJகியாக எ"வித பயப:கிற> எப> ஆராயபட>. விைன நிக!விேபா> ேதாN இைடநிைல ெதா0திக , அகசிவE நிறமாைலமானி ெகா: கடறியப:, விைனவழிGைற விளகபட>. திமநிைல சிைதV Gைறைய பயப:தி Co 3[Co(CN) 6]2 அைனVேசமமான> தனித ப8க அைமE ெகாட Co 3O4 ஆக மாறப: அைவ Li - அயனி மிகலனி ேநமிவாயாக ெசயப: திற 0றி> ஆVக ேமெகா ளப:, அவறி ேமபட திறக விZவாக விவZகப: ளன. ைசயேநா-ெஜ Gைறயி 0ேளாேராெமடேல (Au, Pt, Pd ) மN ைசயேனாெமடேல (Fe, Ru) -கR0 இைடயிலான இைடவிைன Pt-Ru மN Pd-Fe நாேனா >க க உKவாக காரண என தக ஆVக Hல நிKபிகப: ள>. ேமP அைவக ெமதனா மி-ஆசிெஜேனற மN ஆசிெஜ ஒ:க விைனJகியாக பயப:தப: ள>. vi List of Abbreviations TOA-Br Tetraoctylammonium bromide MPCs Monolayer- protected clusters SDS Sodium dodecylsulfate CMC Critical Micelle Concentration BPDC 2– 4, 4 ′-biphenyldicarboxylate UV-Vis Ultraviolet visible SPR Surface plasmon resonance FT-IR Fourier Transform Infrared SNIFTIR Subtractively Normalized Fourier Transform Interfacial Infra Red TGA Thermo-gravimetric analysis XRD X-ray diffraction FWHM Full Width at Half Maximum XPS X-ray Photo electron Spectroscopy SAED Selected Area Electron Diffraction TEM Transmission Electron Microscopy SEM Scanning Electron Microscopy EDS Energy Dispersive x-ray Spectroscopy EIS Electrochemical Impedance Spectroscopy 3–APS 3-AminoPropyl trimethoxy Siloxane PEMFC Proton Exchange Membrane Fuel Cell DMFC Direct Methanol Fuel Cell RHE Reversible Hydrogen Electrode vii upd Under Potential Deposition MW Microwave LIBs Li-ion batteries ppm Parts Per Million SEI Solid Electrolyte Interface PB Prussian blue GC Glassy Carbon Pd-HCF Palladium hexacyanoferrate MeOH Methanol fcc face centred cubic viii Table of contents Page No.