Integration of Cobalt Phthalocyanine, Acetylene Black and Cu2O Nanocubes for Efficient Electroreduction of CO2 to C2H4

A tandem catalyst, Cu₂O NCs-C-Copc, consisting of acetylene black, cobalt phthalocyanine (Copc) and Cu₂O nanocubes was developed for efficient converting of CO₂ to C₂H₄. We propose the Cu₂O NCs-C-Copc mechanism suppressing side reactions and simultaneously enriching CO. Here, we report faradaic efficiencies of C₂H₄ formation of up to 58.42 % at −1.1 V vs. RHE in 0.1 M KHCO₃ and 70.31 % at −0.76 V vs. RHE in 1.0 M KOH.

Abstract

Suppressing side reactions and simultaneously enriching key intermediates during CO₂ reduction reaction (CO₂RR) has been a challenge. Here, we propose a tandem catalyst (Cu₂O NCs-C-Copc) consisting of acetylene black, cobalt phthalocyanine (Copc) and cuprous oxide nanocubes (Cu₂O NCs) for efficient CO₂-to-ethylene conversion. Density-functional theory (DFT) calculation combined with experimental verification demonstrated that Copc can provide abundant CO to nearby copper sites while acetylene black successfully reduces the formation energies of key intermediates, leading to enhanced C₂H₄ selectivity. X-ray photoelectron spectroscopy (XPS) and potentiostatic tests indicated that the catalytic stability of Cu₂O NCs-C-Copc was significantly enhanced compared with Cu₂O NCs. Finally, the industrial application prospect of the catalyst was evaluated using gas diffusion electrolyzers. The of Cu₂O NCs-C-Copc can reach to 58.4 % at −1.1 V vs. RHE in 0.1 M KHCO₃ and 70.3 % at −0.76 V vs. RHE in 1.0 M KOH. This study sheds new light on the design and development of highly efficient CO₂RR tandem catalytic systems.

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