Ce/Ce Ion Redox Shuttle Stabilized Cu for Efficient CO Electroreduction to CH.

The CO electroreduction reaction has advantages in clean and pollution-free carbon conversion, but it still faces challenges in carbon utilization efficiency and improving the selectivity of C products. Although the dynamic Cu state is known to favor the C-C coupling process, the suitable Cu species for electrocatalytic reduction of CO are difficult to maintain under the conditions of strong reduction and large current. Herein, we propose a Ce doping strategy to stabilize the Cu state (Ce/CuO) during the CORR process, which enables a high Faradaic efficiency of 60 % for multi-carbon products (40 % for CH, 14 % for CHCHOH, and 6 % for CHCOOH), and 25 h stability at -1.2 V versus the reversible hydrogen electrode. In situ infrared spectroscopy, in situ X-ray photoelectron spectroscopy combined with density functional theory calculations reveal that the Cu is stabilized by the redox ion pairs of Ce, which reduces the energy barrier of *CO coupling, and improves the Faraday efficiency of electrocatalytic CO reduction of CH. This work provides a new idea to make full use of lanthanide variable value metals for advanced catalysis and clean energy conversion.