Advances in Catalyst and Reactor Design for CO2 Electroreduction to Methanol

Abstract

The electroreduction of CO2 to methanol constitutes an attractive strategy for sustainable energy storage and carbon recycling. Methanol is not only a versatile chemical feedstock but also a liquid energy carrier compatible with existing infrastructure. However, the multi-step proton-electron transfer process and competing reaction pathways significantly limit methanol selectivity and production rates. This review provides a critical overview of recent progress in CO2-to-methanol electro-conversion, including both the direct CO2 reduction reaction and the indirect CO reduction reaction pathway. We focus on mechanistic insights, emphasizing key intermediates such as CO*, CHO*, and CH3O*, and identify structure-activity relationships through operando characterization and density functional theory calculations. The discussion spans a wide range of catalyst platforms, from molecular complexes, single-atom catalysts, and nanoclusters to alloy materials, and explores strategies such as tandem catalysis and interface engineering to increase selectivity and efficiency. We further explore developments in gas-fed flow cells and membrane-electrode assemblies that enable high-rate, stable operation. Finally, we highlight current limitations in catalyst design and system integration and outline emerging strategies to enable scalable and carbon-neutral methanol electrosynthesis.