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 -0.43 V), remarkable durability (>75 h 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-N4 ) is the main active site for CO2RR with low free energy barrier for the formation of *COOH as the rate-limiting step.