Highly Efficient CO2 Electroreduction on ZnN4-based Single-Atom Catalyst

The electrochemical reduction reaction of carbon dioxide (CO2RR) to carbon monoxide (CO) is the basis for the further synthesis of more complex carbon-based fuels or attractive feedstock. Single-atom catalysts have unique electronic and geometric structures with respect to their bulk counterparts, thus exhibiting unexpected catalytic activities. A nitrogen-anchored Zn single-atom catalyst is presented for CO formation from CO2RR with high catalytic activity (onset overpotential down to 24 mV), high selectivity (Faradaic efficiency for CO (FECO) up to 95% at -0.43V), remarkable durability (> 75h without decay of FECO), and large turnover frequency (TOF, up to 9969 h(-1)). Further experimental and DFT results indicate that the four-nitrogen-anchored Zn single atom (Zn-N-4) is the main active site for CO2RR with low free energy barrier for the formation of *COOH as the rate-limiting step.