Simultaneous High Current Density and Selective Electrocatalytic CO-to-CH through Intermediate Balancing.

The electrochemical reduction of CO to CH is promising for carbon neutrality and renewable energy storage but confronts low CH selectivity, especially at high current densities. The key challenge lies in promoting *CO intermediate and *H coupling while minimizing side reactions including C-C coupling and H-H coupling, which is particularly difficult at high current density due to abundant intermediates. Here we report a cooperative strategy to address this challenge using Cu-based catalysts comprising Cu-N coordination polymer and CuO component that can simultaneously manage the key intermediates *CO and *H. A fast CO-to-CH conversion rate of 3.14 mmol cm h is achieved at 1,300 mA cm with a Faradaic efficiency of 51.7 %. In situ spectroscopy and theoretical calculations show that the increased Cu-Cu distance in the Cu-N coordination polymer component favors multistep *CO hydrogenation over the dimerization, and the CuO component ensures an adequate supply of *H, together contributing to the selective CO-to-CH conversion at high current densities. This work develops a cooperative strategy for the electrosynthesis of CH with simultaneous high current density and high selectivity by rational catalyst design, paving the way for its applications.