Journal
ACS CATALYSIS
Volume 10, Issue 16, Pages 9129-9135Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.0c01642
Keywords
density functional theory; graphene; microkinetic model; oxygen reduction reaction; single-atom catalyst
Categories
Funding
- U.S. Department of Energy (DOE) through the Office of Basic Energy Sciences (BES), Catalysis Science Program [DE-FG02-05ER15731]
- National Energy Research Scientific Computing Center (NERSC) [DE-AC02-05CH11231]
- Center for Nanoscale Materials (CNM) at the Argonne National Laboratory [DE-AC02-06CH11357]
- UW-Madison
- Advanced Computing Initiative
- Wisconsin Alumni Research Foundation
- Wisconsin Institutes for Discovery
- National Science Foundation
- Alexander von Humboldt Foundation
Ask authors/readers for more resources
Graphene-based single-atom catalysts are promising alternatives to platinum-based catalysts for fuel cell applications. Different transition metals have been screened using electronic structure methods by estimating onset potentials from the most endergonic elementary reaction step. We calculate onset potentials for the oxygen reduction reaction on metal atoms embedded in N-substituted graphene di-vacancies by virtue of first-principles-informed microkinetic analysis. We find that for more oxophilic metals (Cr, Fe, Mn, and Ru), purely thermodynamic models systematically underestimate onset potentials. Furthermore, the oxophilic metals (Cr, Fe, Mn, and Ru) are oxidized under reaction conditions, leading to an increase in activity compared to their reduced state. Importantly, coadsorbed OmHn species actively participate in the reaction, which requires a dynamic treatment of spectator species. These findings highlight the limitations of thermodynamic analyses for electrocatalytic processes, which commonly assume the same oxidation state for each metal, and show that deviations between computational and experimental onset potentials cannot be solely attributed to the shortcomings of the electronic structure methods.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available