Reaction Free Energy

JACS: Why does the CO₂RR catalyst become increasingly coarse with each reaction? Adsorbed hydrogen provides a new explanation

In the electroreduction of CO₂, the Cu catalyst undergoes simultaneous reaction and reconstruction: the smooth surface gradually roughens, Cu atoms migrate, dissolve, and redeposit, ultimately forming low-coordination clusters. These new structures alter the active sites, directly affecting CO₂ activation, CO coupling, and the formation of multi-carbon products. Previously, Cu reconstruction was often attributed to CO adsorption or reduction potential, but this is insufficient to explain the continuous surface changes occurring over a wide potential range. A JACS paper by the team of Ling Chongyi, Wang Jinlan, and Li Qiang from Southeast University proposes that hydrogen adsorption is the key precursor: it first weakens the Cu–Cu bond and loosens the lattice, then allows intermediates such as CO and COOH to further trigger Cu atom migration and cluster formation.