Comprehensive understanding and rational regulation of microenvironment for gas-involving electrochemical reactions

Abstract

Substantial progress has been made in the understanding of gas-involving electrochemical reactions recently for the sake of clean, renewable, and efficient energy technologies. However, the specific influence mechanism of the microenvironment at the reaction interface on the electrocatalytic performance (activity, selectivity, and durability) remains unclear. Here, we provide a comprehensive understanding of the interfacial microenvironment of gas-involving electrocatalysis, including carbon dioxide reduction reaction and nitrogen reduction reaction, and classify the factors affecting the reaction thermodynamics and kinetics into gas diffusion, proton supply, and electron transfer. This categorization allows a systematic survey of the literature focusing on electrolyzer-level (optimization of the device, control of the experimental condition, and design of the working electrode), electrolyte-level (increase of gas solubility, regulation of proton supply, and substitution of anodic reaction), and electrocatalyst-level strategies (promotion of gas affinity, adjustment of hydrophobicity, and enhancement of conductivity), aiming to retrieve the correlations between the microenvironment and electrochemical performance. Finally, priorities for future studies are suggested to support the comprehensive improvement of next-generation gas-involving electrochemical reactions.