Tailoring the * CO and * H Coverage for Selective CO2 Electroreduction to CH4 or C2 H4.

In the electrochemical CO2 reduction reaction (CO2 RR), the coverages of * CO and * H intermediates on a catalyst surface are critical for the selective generation of C1 or C2 products. In this work, we have synthesized several Cux Zny Mnz ternary alloy electrocatalysts, including Cu8 ZnMn, Cu8 Zn6 Mn, and Cu8 ZnMn2 , by varying the doping compositions of Zn and Mn, which are efficient in binding * CO and * H adsorbates in the CO2 electroreduction process, respectively. The increase of * H coverage allows to promotion of the CH4 and H2 formation, while the increase of the * CO coverage facilitates the production of C2 H4 and CO. As a result, the Cu8 ZnMn catalyst presented a high CO2 -to-CH4 partial current density (-418 ± 22 mA cm-2 ) with a Faradaic efficiency of 55 ± 2.8%, while the Cu8 Zn6 Mn catalyst exhibited a CO2 -to-C2 H4 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.