Preparation of trimetallic electrocatalysts by one-step co-electrodeposition and efficient CO reduction to ethylene.

Use of multi-metallic catalysts to enhance reactions is an interesting research area, which has attracted much attention. In this work, we carried out the first work to prepare trimetallic electrocatalysts by a one-step co-electrodeposition process. A series of Cu-X-Y (X and Y denote different metals) catalysts were fabricated using this method. It was found that CuLaCs (the content ratio of Cu, La, and Cs in the electrolyte is 10 : 1 : 1 in the deposition process), which had an elemental composition of CuLaCs in the catalyst, formed a composite structure on three dimensional (3D) carbon paper (CP), which showed outstanding performance for CO electroreduction reaction (CORR) to produce ethylene (CH). The faradaic efficiency (FE) of CH could reach 56.9% with a current density of 37.4 mA cm in an H-type cell, and the partial current density of CH was among the highest ones up to date, including those over the catalysts consisting of Cu and noble metals. Moreover, the FE of C products (CH, ethanol, and propanol) over the CuLaCs catalyst in a flow cell reached 70.5% with a high current density of 486 mA cm. Experimental and theoretical studies suggested that the doping of La and Cs into Cu could efficiently enhance the reaction efficiency a combination of different effects, such as defects, change of electronic structure, and enhanced charge transfer rate. This work provides a simple method to prepare multi-metallic catalysts and demonstrates a successful example for highly efficient CORR using non-noble metals.