Electrochemistry: Redox Chemistry and Electrocatalysis - Experimental and Simulation Investigations into Novel Mechanisms for the Oxygen Reduction Reaction
Abstract
Fuel cells generate electricity via the electrochemical oxidation of a fuel (typically hydrogen or methanol) and the electrochemical reduction of oxygen. Fuel cells are crucial Army technologies because they can power land and air vehicles as well as provide personal power to soldiers. However, the oxygen reduction reaction (ORR), is the half-reaction that limits the overall efficiency of fuel cells due to the complexity of the 4e-/4H+ electrochemical reaction. The last 15 years have not seen a significant advance in the performance of ORR catalysts. Thus, a paradigm shift is necessary for ORR catalyst design. Here, we are proposing a systematic investigation to determine if it is possible to design an electrocatalytic system to change the mechanism of the ORR. We are going to investigate novel bi-metallic catalysts that have a unique affinity for the different key intermediates that occur during oxygen reduction. This work will be a combination of novel experimental and simulation techniques to probe ORR mechanisms for bi-metallic catalysts. Specifically, we will develop new scanning probe electroanalytical techniques and new simulation models for unraveling mechanistic insights and rate determining steps of the ORR. In this proposal, our objectives are to: (1) Employ numerical deconvolution of Surface Interrogation - Scanning Electrochemical Microscopy (SI-SECM) data to determine if adsorbed protons and oxygenated species co-exist on a catalytic surface. (2) Develop micro-kinetic modeling of voltammetry data to determine ORR mechanisms and rate-determining steps. (3) Design insitu electrochemical characterization techniques to investigate ORR mechanisms under elevated temperatures. If we are successful, this work holds the potential to make transformative advances in ORR catalysis. This is a very challenging problem because progress in ORR activity has been stymied for decades even though significant research efforts have been devoted to it. In addition, the work plan includes developing new electroanalytical, experimental, and computational tools that will provide broad benefits to the electrocatalysis community.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 12, 2022
- Source ID
- W911NF2210293
Entities
People
- Kevin C Leonard
Organizations
- Army Contracting Command
- United States Army
- University of Kansas