High dispersion dendritic fibrous morphology nanospheres for electrochemical CO2 reduction to C2H4

Abstract

The electrochemical CO2 reduction to specific multi-carbon product on copper-based catalysts is subjected to low activity and poor selectivity. Herein, catalyst structure, morphology, and chemical component are systematically studied for bolstering the activity and selectivity of as-prepared catalyzers in this study. Dendritic fibrous nano-silica spheres favor the loading of active species and the transport of reactant from the central radial channel. Cu/DFNS with high dispersion active sites are fabricated through urea-assisted precipitation way. The coexistence of Cu(I)/Cu(II) induces a close combination of Cu active sites and CO2 on the Cu/DFNS interface, promoting the CO2 activation and CC coupling. The Cu–O–Si interface (Cu phyllosilicate) can improve CO2 and CO attachment. Cu/DFNS show the utmost Faradaic efficiency of C2H4 with a value of 53.04% at −1.2 V vs. RHE. And more importantly, in-situ ATR-SEIRAS reveals that the CC coupling is boosted for effectively producing C2H4 as a consequence of the existence of *COL, *COOH, and *COH intermediates. The mechanism reaction path of Cu/DFNS is inferred to be *CO2 → *COOH → *CO → *CO*COH → C2H4. Our findings will be helpful to gain insight into the links between morphology, texture, chemical component of catalyzers, and electrochemical reduction of CO2, providing valuable guidance in the design of more efficient catalysts.