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

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 *CO_L, *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.