Catalysts, Vol. 15, Pages 623: Preparation of Cu-La Bimetallic Catalysts by Electrodeposition for the Electrocatalytic Promotion of CO2 to CH4

Catalysts doi: 10.3390/catal15070623

Authors:
Caidong Du
Wenwei Wu
Jiangtao Shang
Keyi Xiang

Methane (CH4) has attracted much attention regarding its use in electrochemical carbon dioxide reduction reaction (CO2RR) due to its high mass-energy density; however, the uneven adsorption of intermediates on copper sites by conventional Cu-based catalysts limits the selective production of CH4. The introduction of a second metal can effectively regulate the adsorption energy of intermediates on the Cu site. In this paper, a method of alloying Cu with oxyphilic metals (M) using rapid electrodeposition is presented; the synergistic effect of the bimetal effectively directed the reaction pathway toward CH4. The best Faraday efficiency for methane occurred in the optimized Cu30La20 electrode, reaching 66.9% at −1.7 V vs. RHE potential. In situ infrared testing revealed that the *CHO intermediate—a critical species for the electrocatalytic conversion of CO2 to CH4—was detected on the Cu30La20 catalytic electrode. However, no *CHO intermediate was observed on the Cu20La30 electrode. Instead, the characteristic peak of the *OCCHO intermediate associated with C-C coupling emerged on the Cu20La30 catalyst. This indicates that the adsorbed oxygen-containing groups on lanthanum sites reacted with carbon-containing groups on copper sites to form C2 products, serving as the primary reason for the shift in reduction products from methane to ethylene.

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