In Situ Reconstruction of a Hierarchical Sn-Cu/SnO Core/Shell Catalyst for High-Performance CO Electroreduction.

The electrochemical CO reduction reaction (CO RR) to give C (formate and CO) products is one of the most techno-economically achievable strategies for alleviating CO emissions. Now, it is demonstrated that the SnO shell in Sn Cu catalyst with a hierarchical Sn-Cu core can be reconstructed in situ under cathodic potentials of CO RR. The resulting Sn Cu catalyst achieves a high current density of 406.7±14.4 mA cm with C Faradaic efficiency of 98.0±0.9 % at -0.70 V vs. RHE, and remains stable at 243.1±19.2 mA cm with a C Faradaic efficiency of 99.0±0.5 % for 40 h at -0.55 V vs. RHE. DFT calculations indicate that the reconstructed Sn/SnO interface facilitates formic acid production by optimizing binding of the reaction intermediate HCOO* while promotes Faradaic efficiency of C products by suppressing the competitive hydrogen evolution reaction, resulting in high Faradaic efficiency, current density, and stability of CO RR at low overpotentials.