Nanoporous Silver-Modified Lacoo3-Delta Perovskite For Oxygen Reduction Reaction

Substantial progress has been made in developing perovskite-based catalysts for oxygen reduction reaction (ORR). This article reported an ORR electrocatalyst composed of nanoporous Ag (NP-Ag) and LaCoO3-delta (LC) perovskite oxide and designed to take advantage of the bi-continuous NP structure and high electrocatalytic performance of perovskite oxides. The triple-phase boundaries (TPBs) formed by NP-Ag and LC provided active sites for the electrocatalytic reactions. Further annealing promoted the interaction between NP-Ag and LC, which induced the formation of more Co3+ and surface oxygen vacancies, as proved by multiple characterizations. When the mass ratio of LC and NP-Ag was 1:2 (LC/Ag-1/ 2-A), the catalyst showed the best ORR performance with a relatively high half-wave potential, and only attenuated by 4% after 5,000 cycles of accelerated durability testing. Besides, it delivered significant bifunctionality towards both ORR and OER, bearing comparison with the reported perovskite-based electrocatalysts. This work demonstrated a novel route for extending the application of NP metals and facilely designing efficient bifunctional electrocatalysts. (C) 2021 Elsevier Ltd. All rights reserved.