Abstract:

Copper-based electrocatalysts have great potential to produce high-value products in CO₂ reduction reaction (CO₂RR), offering a promising way to achieve negative carbon emissions. Additionally, achieving ampere-level currents is crucial for realizing the industrialization of multi-carbon (C₂₊) products. However, the C₂₊ selectivity at industrial current densities remains unsatisfactory due to complex electron transport processes and inevitable side reactions. Herein, we developed a carbon-modification strategy aimed at optimizing the local environment and regulating the adsorption of intermediates at Cu active sites. Our findings demonstrated the effectiveness of Cu-C_x catalysts (where 'x' denoted the atomic percentage of C in the catalysts) in facilitating CO₂RR for producing C₂₊ products. Especially, over Cu-C_6%, the current density could reach to 1.25 A∙cm^-2 at -0.72 V vs. RHE (versus reversible hydrogen electrode) in a flow cell, and the Faradaic efficiency (FE) of C₂H₄ and C₂₊ products could reach to 54.4% and 80.2%, respectively. In situ spectral analysis and density functional theory (DFT) calculations showed that the presence of C regulated the adsorption of ^*CO on Cu surface, reduced the energy barrier of C—C coupling, thus promoting the production of C₂₊ products.

Key words: CO₂ reduction, Electrocatalysis, Multi-carbon products, Green chemistry, Ampere-level current