Catalyst design and reactor engineering for electrochemical CO2 reduction to formate and formic acid

The potential for directly converting CO₂ to valuable liquid fuels utilizing green and renewable electricity has sparked significant interest in CO₂ electroreduction (CO₂RR). In recent years, CO₂ conversion to formate/formic acid (HCOO⁻/HCOOH) has witnessed fast growth due to its economic and technological viability combined with the development of highly selective catalysts and practical electrolyzes. In this review, we summarize and discuss recent advances in HCOOH generation from CO₂ reduction in terms of (1) the rationale behind choosing HCOOH as a CO₂ electroreduction product, (2) mechanistic pathways to form HCOOH, (3) novel electrocatalyst developments for enhanced HCOOH production, and (4) electrolyzer designs that tackle practical challenges in scalability, reaction rate, and product impurities. Finally, a brief outlook on future opportunities in this field is offered to accelerate the industrialization of CO₂RR to HCOOH.