Abstract
Guided by computational Pourbaix screening and high-throughput experiments aimed at the development of precious-metal-free fuel cells, we investigate rutile CoSb2O6 as an electrocatalyst for oxygen reduction in 1 M sulfuric acid. Following 4 h of catalyst conditioning at 0.7 V vs RHE, operation at this potential for 20 h yielded an average current density of -0.17 mA cm-2 with corrosion at a rate of 0.04 nm hour-1 that is stoichiometric with catalyst composition. Surface Pourbaix analysis of the (111) surface identified partial H coverage under operating conditions. The Sb active site has an HO∗ binding free energy of 0.49 eV, which is near the peak of the kinetic 4e- ORR volcano for transition-metal oxides in acidic conditions. The experimental demonstration of operational stability and computational identification of a reaction pathway with favorable energetics place rutile CoSb2O6 among the most promising precious-metal-free electrocatalysts for oxygen reduction in acidic media.
Original language | English |
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Journal | ACS Energy Letters |
Volume | 7 |
Issue number | 3 |
Pages (from-to) | 993-1000 |
Number of pages | 8 |
ISSN | 2380-8195 |
DOIs | |
Publication status | Published - 2022 |