2021 Annual Meeting

(371b) Mechanistic Understanding of Electrochemical Processes in Alkaline Environments

Authors

Schimmenti, R. - Presenter, University of Wisconsin-Madison
Murray, E. A., University of Wisconsin-Madison
Mavrikakis, M., University of Wisconsin - Madison
Alkaline fuel cells (FCs) have attracted attention for potential applications in energy production technologies. The higher stability of non-precious metals in alkaline environment offers the possibility to synthesize cheaper electrocatalysts, lowering the overall cost of FCs [1]. However, non-precious metals are considerably less active than more commonly used PGM-electrocatalysts. As a result, successful deployment of high-performance alkaline precious metal-free FC remains a challenge. Mechanistic understanding of electrocatalytic processes could greatly contribute to the design of improved electrocatalysts. At present, comprehensive mechanistic models capable of capturing the in situ nature of the catalytic active site in alkaline environment are still lacking.

In this contribution, we utilize electronic-structure calculations to unravel complex reaction mechanisms in alkaline environments. We will focus on two technologically-relevant reactions, the oxygen reduction reaction (ORR) on Au(100) and the ammonia oxidation reaction (AOR) on Pt(111). By using solvent-, coverage-, and potential-cognizant static and molecular dynamics simulations in conjunction with microkinetic models, we are going to shed light on the following key questions i. “What is the origin of the remarkable activity of Au(100) for ORR in alkaline environment?”[2] and ii. “What is source of Pt deactivation in the AOR?” [3-7].

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[6] Herron J. A., Ferrin P., Mavrikakis M., J. Phys. Chem. C, 119, 14692–14701 (2015).

[7] Elnabawy A., Herron J. A., Karraker S., Mavrikakis M., J. Catal. (2021), in press.