Beyond catalytic materials: Controlling local gas/liquid environment in the catalyst layer for CO2 electrolysis

Electrochemical reduction of CO2 to value-added chemicals using renewable electricity provides a promising strategy to achieve sustainable fuel production and carbon neutrality. Along with the development of electrocatalysts, flow cells with gas-diffusion electrodes (GDEs) have been used to reach commercially viable current densities for CO2 electrolysis, while the local environment and CO2 mass transport in the electrodes remain to be elucidated. In this review article, we highlight some insights into the microenvironment in the catalyst layer for CO2 electrolysis, including typical mass transport models for CO2 reduction in H-type cells and GDE flow cells, the effect of a hydrophobic microenvironment on CO2 mass transport and catalytic performance, and the formation of a gas/liquid balance and solid-liquid-gas interfaces for CO2 electrolysis. The insights and discussions in this article can provide important guidelines on the design of catalysts, electrodes, and electrolyzers for CO2 electrolysis, as well as other gas-involving electrocatalytic reactions. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Electrochemical reduction of CO2 to value-added chemicals using renewable electricity is crucial for sustainable fuel production and carbon neutrality. This review highlights insights into the microenvironment in the catalyst layer for CO2 electrolysis, providing important guidelines for the design of key components in CO2 electrolysis.