University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Fall 2020 TUNING SURFACE PROPERTIES OF TITANIUM DIOXIDE FOR CARBON MONOXIDE OXIDATION OVER COPPER-TITANIUM DIOXIDE Guoqiang Cao University of New Hampshire, Durham Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation Cao, Guoqiang, "TUNING SURFACE PROPERTIES OF TITANIUM DIOXIDE FOR CARBON MONOXIDE OXIDATION OVER COPPER-TITANIUM DIOXIDE" (2020). Doctoral Dissertations. 2538. https://scholars.unh.edu/dissertation/2538 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. TUNING SURFACE PROPERTIES OF TITANIUM DIOXIDE FOR CARBON MONOXIDE OXIDATION OVER COPPER-TITANIUM DIOXIDE BY GUOQIANG CAO Baccalaureate Degree, Mineral Processing Engineering, China University of Mining and Technology, Beijing, China, 2012 Master of Science, Mineral Processing Engineering, China University of Mining and Technology, Beijing, China, 2015 DISSERTATION Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Chemical Engineering September, 2020 This dissertation has been examined and approved in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemical Engineering by: Dissertation Director, Dr. Nan Yi Assistant Professor of Chemical Engineering, UNH Dr. Xiaowei Teng Professor and Chair of Chemical Engineering, UNH Dr. Nivedita Gupta Professor of Chemical Engineering, UNH Dr. Young Jo Kim Assistant Professor of Chemical Engineering, UNH Dr. Gonghu Li Professor of Chemistry, UNH On July 24th, 2020 Original approval signatures are on file with the University of New Hampshire Graduate School. TABLE OF COTENT ACKNOWLEDGMENTS .......................................................................................................... vii LIST OF TABLES ....................................................................................................................... ix LIST OF FIGURES ...................................................................................................................... x ABSTRACT ................................................................................................................................xiv CHAPTER 1 INTRODUCTION ................................................................................................ 1 1.1 CARBON MONOXIDE OXIDATION ............................................................................. 1 1.2 CATALYSTS .................................................................................................................... 4 1.2.1 METAL CATALYSTS ........................................................................................... 4 1.2.2 SUPPORTED METAL CATALYSTS ................................................................... 8 1.2.3 COPPER-METAL OXIDES ................................................................................. 16 1.3 MECHANISM AND KINETICS ..................................................................................... 20 1.3.1 MECHANISM ....................................................................................................... 20 1.3.2 KINETICS ............................................................................................................. 22 1.4 RATIONALES AND OBJECTIVES ............................................................................... 25 CHAPTER 2 EXPERIMENTAL METHODS ........................................................................ 27 2.1 SYNTHESIS OF CATALYSTS ...................................................................................... 27 2.1.1 SYNTHESIS OF Cu-TiO2 CATALYSTS WITH INEQUAL HYDROXYL GROUPS ............................................................................................................... 28 2.1.2 SYNTHESIS OF Cu-N-TiO2 CATALYSTS WITH VARIOUS PHASES .......... 29 iii 2.1.3 SYNTHESIS OF Cu-TiO2 CATALYSTS WITH DIFFERENT CALCINATION GAS....................................................................................................................... 30 2.2 CATALYSTS CHARACTERIZATIONS ....................................................................... 30 2.2.1 INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROSCOPY (ICP-AES) ............................................................................................................. 30 2.2.2 X-RAY POWDER DIFFRACTION (XRD) ......................................................... 31 2.2.3 BRUNAUER-EMMETT-TELLER SURFACE AREA (BET) ............................. 31 2.2.4 LASER RAMAN SPECTROSCOPY (RAMAN)................................................. 31 2.2.5 COPPER DISPERSION ........................................................................................ 32 2.2.6 TEMPERATURE PROGRAMMED SURFACE REACTION (TPR & TPSR) .. 33 2.2.7 X-RAY PHOTOELECTRON SPECTROSCOPY (XPS) ..................................... 34 2.2.8 IN-SITU DIFFUSE REFLECTANCE INFRARED FOURIER TRANSFORM SPECTROSCOPY (IN-SITU DRIFTS) ............................................................... 35 2.3 CATALYTIC PERFORMANCE..................................................................................... 35 CHAPTER 3 EFFECT OF HYDROXYL GROUPS ON CARBON MONOXIDE OXIDATION OVER COPPER-TITANIUM DIOXIDE CATALYSTS ....... 37 3.1 INTRODUCTION ........................................................................................................... 37 3.2 CARBON MONOXIDE OXIDATION ACTIVITY OVER CU-TIO2 CATALYSTS ..... 39 3.3 CHARACTERIZATION OF CU-TIO2 CATALYSTS .................................................... 43 3.3.1 PHYSICAL PROPERTIES ................................................................................... 43 3.3.2 REDOX BEHAVIOURS ....................................................................................... 45 3.3.3 CHEMICAL STATES ANALYSIS ...................................................................... 48 3.3.4 IN-SITU DRIFTS .................................................................................................. 51 iv 3.4 SUMMARY ..................................................................................................................... 53 CHAPTER 4 EFFECT OF PRETREATMENT ON COPPER-TITANIUM DIOXIDE CATALYZED CARBON MONOXIDE OXIDATION ................................... 55 4.1 INTRODUCTION ........................................................................................................... 55 4.2 CARBON MONOXIDE OXIDATION ACTIVITY OVER CU-TIO2 CATALYSTS CALCINED IN DIFFERENT GAS ATMOSPHERE ..................................................... 56 4.3 CHARACTERIZATION OF PRETREATED CU-TIO2 CATALYSTS .......................... 58 4.3.1 PHYSICAL PROPERTIES ................................................................................... 58 4.3.2 REDOX BEHAVIOURS ....................................................................................... 59 4.3.3 CHEMICAL STATES ANALYSIS ...................................................................... 61 4.3.4 IN-SITU DRIFTS .................................................................................................. 65 4.4 SUMMARY ..................................................................................................................... 66 CHAPTER 5 EFFECT OF NITROGEN DOPING ON CARBON MONOXIDE OXIDATION OVER COPPER-TITANIUM DIOXIDE CATALYSTS ....... 68 5.1 INTRODUCTION ........................................................................................................... 68 5.2 CARBON MONOXIDE OXIDATION ACTIVITY OVER CU-N-TIO2 CATALYST ... 70 5.3 CHARACTERIZATION OF CU-N-TIO2 CATALYSTS ................................................ 72 5.3.1 PHYSICAL PROPERTIES ................................................................................... 72 5.3.2 CHEMICAL STATES ANALYSIS ...................................................................... 74 5.3.3 REDOX PROPORTIES ........................................................................................ 79 5.3.4 IN-SITU DRIFTS .................................................................................................. 83 5.4 SUMMARY ..................................................................................................................... 84 v CHAPTER 6 EFFECT OF TITANIUM DIOXIDE PHASES ON COPPER-NITROGEN- TITANIUM DIOXIDE CATALYZED CARBON MONOXIDE OXIDATION ....................................................................................................... 87 6.1 INTRODUCTION ........................................................................................................... 87 6.2 CARBON MONOXIDE OXIDATION ACTIVITY ....................................................... 89 6.3 CHARACTERIZATION OF CU-N-TIO2 CATALYSTS ................................................ 91 6.3.1 PHYSICAL PROPERTIES ................................................................................... 91 6.3.2 CHEMICAL STATES ANALYSIS ...................................................................... 94 6.3.3 REDOX PROPORTIES ...................................................................................... 100 6.3.4 IN-SITU DRIFTS ...............................................................................................