Active hydrogen-controlled CO2/N2/NOx electroreduction:From mechanism understanding to catalyst design

The development of renewable-energy-powered electrocatalysis meets the need for the sustainable society. With water as the proton source, it enables efficient production of chemicals and fuels from renewable resources like CO2, N2, and NOx under ambient conditions. Hydrogen generated via water dissociation is a crucial participant in transforming reactants into desired products, but it also serves as a direct source of undesired reactions when in excess. In this review, we first present an overview of the functional mechanisms of active hydrogen in the electroreduction of CO2/N2/NOx. We then introduce a range of methods to enhance our understanding of these mechanisms. Furthermore, a detailed discussion of design strategies aimed at regulating active hydrogen in the reduction of CO2/N2/NOx is provided. Finally, an outlook on the critical challenges remaining in this research area and promising opportunities for future research is considered.