Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2017 Electrocatalytic conversion of biorenewable feedstocks for electricity and chemicals cogeneration in anion exchange membrane fuel cells Neeva Benipal Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Chemical Engineering Commons Recommended Citation Benipal, Neeva, "Electrocatalytic conversion of biorenewable feedstocks for electricity and chemicals cogeneration in anion exchange membrane fuel cells" (2017). Graduate Theses and Dissertations. 15259. https://lib.dr.iastate.edu/etd/15259 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Electrocatalytic conversion of biorenewable feedstocks for electricity and chemicals cogeneration in anion exchange membrane fuel cells by Neeva K. Benipal A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Chemical Engineering Program of Study Committee: Wenzhen Li, Major Professor Jean-Philippe Tessonnier Robert C. Brown Eric W. Cochran Wenyu Huang The student author and the program of study committee are solely responsible for the content of this dissertation. The Graduate College will ensure this dissertation is globally accessible and will not permit alternations after a degree is conferred. Iowa State University Ames, IA 2017 Copyright © Neeva K. Benipal, 2017. All rights reserved. ii To my both grandfathers, Raghbir S. Benipal and Surjit S. Gill iii TABLE OF CONTENTS LIST OF FIGURES ..................................................................................................................... viii LIST OF SUPPLEMENTARTY FIGURES .................................................................................. xi LIST OF TABLES ........................................................................................................................ xii LIST OF SUPPLEMENTARY TABLES .................................................................................... xiii NOMENCLATURE .................................................................................................................... xiv ACKNOWLEDGMENTS ........................................................................................................... xvi ABSTRACT ............................................................................................................................... xviii CHAPTER 1 BACKGROUND AND SIGNIFICANCE OF THE RESEARCH ........................... 1 1.1 Introduction ........................................................................................................................... 1 1.2 Biorefinery ............................................................................................................................ 3 1.3 Electro-biorefinery: Fuel Cells .............................................................................................. 5 1.4 Selective catalytic oxidation of polyols and sugars .............................................................. 9 1.5 Research Objectives ............................................................................................................ 12 1.6 References ........................................................................................................................... 13 CHAPTER 2 REVIEW OF ELECTROCATALYTIC CONVERSION OF BIO- BASED DERIVED GLYCEROL TO CHEMICALS .................................................................. 18 2.1 Abstract ............................................................................................................................... 18 2.2 Introduction ......................................................................................................................... 19 2.3 Electrocatalytic oxidation of alcohols ................................................................................. 21 2.3.1 Glycerol: a model polyol compound ............................................................................ 22 2.3.2 Thermodynamics .......................................................................................................... 24 2.3.3 Electrode material (electrocatalysts) ............................................................................ 26 2.3.4 Electrode potential and current density ........................................................................ 27 2.3.5 Electrolyte pH ............................................................................................................... 28 2.3.6 Proposed oxidation mechanism and current understanding gaps ................................. 29 2.4 Conclusions and future directions ....................................................................................... 34 2.5 References ........................................................................................................................... 35 iv CHAPTER 3 CARBON NANOTUBE SUPPORTED PDAG NANOPARTICLES FOR ELECTROCATALYTIC OXIDATION OF GLYCEROL IN ANION EXCHANGE MEMBRANE FUEL CELLS ................................................................................ 41 3.1 Abstract ............................................................................................................................... 42 3.2 Introduction ......................................................................................................................... 43 3.3 Experimental ....................................................................................................................... 47 3.3.1 Chemicals ..................................................................................................................... 47 3.3.2 Catalyst synthesis and physical characterizations ........................................................ 47 3.3.3 Electrocatalytic oxidation of glycerol and reaction intermediates in a three-electrode cell ................................................................................................................ 48 3.3.4 Electrocatalytic oxidation of glycerol in anion exchange membrane – direct glycerol fuel cells (AME-DGFCs) .............................................................................. 49 3.3.5 Product analysis of glycerol oxidation in AEM-DGFC ............................................... 50 3.4 Results and discussion ......................................................................................................... 51 3.4.1 Physical characterization of mono and bimetallic Pd and Ag electrocatalysts ...................................................................................................................... 51 3.4.2 Electrocatalytic oxidation of glycerol study of Pd/CNT, PdAg/CNT, PdAg3/CNT, and Ag/CNT in half-cell .................................................................................. 57 3.4.3 Electrocatalytic oxidation of glycerol study of Pd/CNT, PdAg/CNT, and PdAg3/CNT in single-cell ............................................................................................... 58 3.4.4 Glycerol oxidation product distribution in AEMFCs on Pd/CNT, PdAg/CNT, and PdAg3/CNT................................................................................................. 59 3.4.5 Electrocatalytic oxidation of glycerol oxidation intermediates in half- cell ......................................................................................................................................... 61 3.4.6 Electrocatalytic oxidation of glycerol oxidation intermediates in single cell ......................................................................................................................................... 66 3.4.7 Proposed reaction pathway for glycerol oxidation over PdAg/CNT ............................ 66 3.5 Conclusions ......................................................................................................................... 68 3.6 Acknowledgements ............................................................................................................. 69 3.7 References ........................................................................................................................... 70 3.8 Supplementary Information ................................................................................................. 74 v CHAPTER 4 ELECTROCATALYTIC OXIDATION OF MESO-ERYTHRITOL IN ANION-EXCHANGE MEMBRANE ALKALINE FUEL CELL WITH PDAG/CNT CATALYST ............................................................................................................. 77 References ................................................................................................................................. 89 Supplementary Information ....................................................................................................... 92 4.1 Experimental ....................................................................................................................... 92 4.1.1 Chemicals ..................................................................................................................... 92 4.1.2 Electrocatalytic oxidation of meso-erythritol and intermediates in