Copper-on-nitride enhances the stable electrosynthesis of multi-carbon products from CO<sub>2</sub>.

Liang, Zhi-Qin; Zhuang, Tao-Tao; Seifitokaldani, Ali; Li, Jun; Huang, Chun-Wei; Tan, Chih-Shan; Li, Yi; De Luna, Phil et al. · Nat Commun · 2018

basic_science · Level V

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Abstract

Copper-based materials are promising electrocatalysts for CO2 reduction. Prior studies show that the mixture of copper (I) and copper (0) at the catalyst surface enhances multi-carbon products from CO2 reduction; however, the stable presence of copper (I) remains the subject of debate. Here we report a copper on copper (I) composite that stabilizes copper (I) during CO2 reduction through the use of copper nitride as an underlying copper (I) species. We synthesize a copper-on-nitride catalyst that exhibits a Faradaic efficiency of 64 ± 2% for C2+ products. We achieve a 40-fold enhancement in the ratio of C2+ to the competing CH4 compared to the case of pure copper. We further show that the copper-on-nitride catalyst performs stable CO2 reduction over 30 h. Mechanistic studies suggest that the use of copper nitride contributes to reducing the CO dimerization energy barrier-a rate-limiting step in CO2 reduction to multi-carbon products.