Recent Advances in Design of Electrocatalysts for High-Current-Density Water Splitting

TL;DR

This paper reviews recent progress in designing electrocatalysts capable of high-current-density water splitting, emphasizing multiscale strategies and key factors influencing performance for industrial green hydrogen production.

Contribution

It provides a comprehensive summary of recent advances, highlighting design strategies and key factors affecting high-current-density electrocatalysts for water splitting.

Findings

Catalyst activity and stability are influenced by local reaction environment.

Multiscale design strategies are effective for developing high-current-density catalysts.

Recent catalysts achieve industrially relevant current densities (>200 mA cm-2).

Abstract

Electrochemical water splitting technology for producing "green hydrogen" is important for the global mission of carbon neutrality. Electrocatalysts with decent performance at high current densities play a central role in the industrial implementation of this technology. The field has advanced immensely in recent years, as witnessed by many types of catalysts have been designed and synthesized which work at industrially-relevant current densities (> 200 mA cm-2). Note that the activity and stability of catalysts can be influenced by their local reaction environment, which are closely related to the current density. By discussing recent advances in this field, we summarize several key aspects that affect the catalytic performance for high-current-density electrocatalysis, including dimensionality of catalysts, surface chemistry, electron transport path, morphology, and catalyst-electrolyte interplay. We highlight the multiscale design strategy that considers these aspects comprehensively for developing high-current-density catalysts. We also put forward out perspectives on the future directions in this emerging field.