Enhanced CO<sub>2</sub> Electrochemical Reduction Performance over Cu@AuCu Catalysts at High Noble Metal Utilization Efficiency.

Dai, Sheng; Huang, Tzu-Hsi; Liu, Wei-I; Hsu, Chia-Wei; Lee, Sheng-Wei; Chen, Tsan-Yao; Wang, Ya-Chen; Wang, Jeng-Han et al. · Nano Lett · 2021

basic_science · Level V

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Abstract

The electrochemical CO<sub>2</sub> reduction reaction (CO<sub>2</sub>RR) represents a viable alternative to help close the anthropogenic carbon cycle and convert intermittent electricity from renewable energy sources to chemical energy in the form of value-added chemicals. The development of economic catalysts possessing high faradaic efficiency (FE) and mass activity (MA) toward CO<sub>2</sub>RR is critical in accelerating CO<sub>2</sub> utilization technology. Herein, an elaborate Au-Cu catalyst where an alloyed AuCu shell caps on a Cu core (Cu@AuCu) is developed and evaluated for CO<sub>2</sub>-to-CO electrochemical conversion. Specific roles of Cu and Au for CO<sub>2</sub>RR are revealed in the alloyed core-shell structure, respectively, and a compositional-dependent volcano-plot is disclosed for the Cu@AuCu catalysts toward selective CO production. As a result, the Au<sub>2</sub>-Cu<sub>8</sub> alloyed core-shell catalyst (only 17% Au content) achieves an FE<sub>CO</sub> value as high as 94% and an MA<sub>CO</sub> of 439 mA/mg<sub>Au</sub> at -0.8 V (vs RHE), superior to the values for pure Au, reflecting its high noble metal utilization efficiency.