Electricity-driven CO2 and biomass conversion toward formic acid/formate: microenvironment regulation, hydrogen storage potential, and sustainability assessment

Abstract

Formic acid (FA)/formate (FM) is widely recognized as an important energy carrier and high-value chemical. Through electrocatalysis, abundant carbon sources such as CO2 and biomass can be converted into FA or FM, enabling the valorization of feedstocks into high-value chemicals via a promising approach toward eco-friendly and sustainable development. This review elucidates recent milestones and emerging trends in FA/FM production via CO2 electroreduction and biomass electrooxidation, with a particular emphasis on microenvironment regulation. The intrinsic mechanisms underlying the effects of key factors on activity, selectivity, and energy efficiency are elucidated. In addition, environmental impact, hydrogen-storage capabilities, techno-economic analysis, and life cycle assessment are discussed in detail. Finally, future research directions and optimization strategies are proposed, focusing on feedstock pretreatment, catalyst engineering, and membrane–electrode integration. More importantly, this review also discusses CO2–organic paired electrolysis, proposing several solutions to fundamental constraints. Overall, this review aims to provide systematic guidance for three electrocatalytic pathways toward FA/FM—CO2 reduction, biomass oxidation, and their paired electrolysis—highlighting the pivotal role of microenvironment engineering in electrocatalyst design and reaction optimization, thereby delivering scientific insights to support green energy utilization and sustainable chemical manufacturing.