Transfer learning aided high-throughput computational design of oxygen evolution reaction catalysts in acid conditions

Sluggish oxygen evolution reaction(OER)in acid conditions is one of the bottlenecks that prevent the wide adoption of proton exchange membrane water electrolyzer for green hydrogen production.Despite recent advancements in developing high-performance catalysts for acid OER,the current electrocatalysts still rely on iridium-and ruthenium-based materials,urging continuous efforts to discover better performance catalysts as well as reduce the usage of noble metals.Pyrochlore structured oxide is a family of potential high-performance acid OER catalysts with a flexible compositional space to tune the electrochemical capabilities.However,exploring the large composition space of pyrochlore compounds demands an imperative approach to enable efficient screening.Here we present a highthroughput screening pipeline that integrates density functional theory calculations and a transfer learning approach to predict the critical properties of pyrochlore compounds.The high-throughput screening recommends three sets of candidates for potential acid OER applications,totaling 61 candidates from 6912 pyrochlore compounds.In addition to 3d-transition metals,p-block metals are identified as promising dopants to improve the catalytic activity of pyrochlore oxides.This work demonstrates not only an efficient approach for finding suitable pyrochlores towards acid OER but also suggests the great compositional flexibility of pyrochlore compounds to be considered as a new materials platform for a variety of applications.

Tungsten Blue Oxide as a Reusable Electrocatalyst for Acidic Water Oxidation by Plasma-Induced Vacancy Engineering

In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials with intrinsically poor electrocatalytic activity can be turned into active electrocatalysts that drive the acidic oxygen evolution reaction(OER)effectively.This development is achieved through ultrafast plasma sputtering,which introduces abundant oxygen vacancies that reconstruct the surface electronic structures,and thus,regulated the surface interactions of electrocatalysts and the OER intermediates.Using tungsten oxide(WO_(3))as an example,we present a broad spectrum of theoretical and experimental characterizations that show an improved energetics of OER originating from surface oxygen vacancies and resulting in a significantly boosted OER performance,compared with pristine WO_(3).Our result suggests the efficacy of using defect chemistry to modify electronic properties and hence to improve the OER performance of known materials with poor activity,providing a new direction for the discovery of acid-stable OER catalysts.