Tailoring the *CO and *H Coverage for Selective CO2 Electroreduction to CH4 or C2H4

Abstract In the electrochemical CO 2 reduction reaction (CO 2 RR), the coverages of * CO and * H intermediates on a catalyst surface are critical for the selective generation of C 1 or C 2 products. In this work, we have synthesized several Cu x Zn y Mn z ternary alloy electrocatalysts, including Cu 8 ZnMn, Cu 8 Zn 6 Mn, and Cu 8 ZnMn 2 , by varying the doping compositions of Zn and Mn, which are efficient in binding * CO and * H adsorbates in the CO 2 electroreduction process, respectively. The increase of * H coverage allows to promotion of the CH 4 and H 2 formation, while the increase of the * CO coverage facilitates the production of C 2 H 4 and CO. As a result, the Cu 8 ZnMn catalyst presented a high CO 2 ‐to‐CH 4 partial current density (−418 ± 22 mA cm −2 ) with a Faradaic efficiency of 55 ± 2.8%, while the Cu 8 Zn 6 Mn catalyst exhibited a CO 2 ‐to‐C 2 H 4 partial current density (−440 ± 41 mA cm −2 ) with a Faradaic efficiency of 58 ± 4.5%. The study suggests a useful strategy for rational design and fabrication of Cu electrocatalysts with different doping for tailoring the reduction products.