Simultaneous Activation of Different Coordination Sites in Single-Phase FeCoMo3O8 for the Oxygen Evolution Reaction

Publication Name

ACS Energy Letters

Abstract

ABMo3O8 is an emerging oxygen evolution reaction (OER) electrocatalyst, exhibiting dual coordination sites for transition metals with good conductivity. However, it is unclear which sites are active for the OER and how to activate them both. Herein, we demonstrated experimentally that only tetrahedral (Td) Co sites are highly active in Co2Mo3O8, and octahedral (Oh) sites are activated by introducing Fe. Various synchrotron X-ray based spectroscopies confirmed the allocation of Co2+ at Td and Fe2+ at Oh sites. The dual activation of different sites improved the OER efficiency with overpotentials of 308 mV@10 mA cm-2 and 361 mV@100 mA cm-2. This unique structure with corner-shared Td Co and Oh Fe in high spin states increases the active site numbers, produces synergistic effects, optimizes the adsorption of intermediates, and creates an unobstructed spin channel for electron transfer. This work provides an effective strategy to design a pair of OER catalysts by coordination engineering.

Open Access Status

This publication is not available as open access

First Page

4506

Last Page

4513

Funding Number

AHY100000

Funding Sponsor

Australian Research Council

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Link to publisher version (DOI)

http://dx.doi.org/10.1021/acsenergylett.3c01747