Electrocatalytic carbon dioxide reduction reaction (eCO 2 RR) is one of the attractive approaches to CO 2 utilization. Nevertheless, it remains a challenge to prepare highly efficient and selective electrocatalysts to realize deep conversion of multi-carbon products. The absence of active sites due to the reconfiguration of copper-based catalysts leads to migration deactivation during catalysis, rendering low catalytic efficiency. In this work, Cu 2 Se nanowires (NWs) were obtained from the Cu foam. After further electroreduction for 90 s, Ag nanoparticles (NPs) were modified on the flower rod-shaped Cu 2 Se NWs (Ag 2.69% /Cu 2 Se NWs). This interfacial modification strategy, balanced the Cu δ+ active valence state on the surface of the Ag 2.69% /Cu 2 Se NWs, led to a high Faradaic efficiency (FE) of ethanol (∼70 %) at −0.52 V (vs. reversible hydrogen electrode (RHE)). Besides, the Ag 2.69% /Cu 2 Se NWs achieved a high partial current (∼13.9 mA) for ethanol, 18.5 μmol/h ethanol yield and an energy efficiency of 47.1 % in the H-type electrolytic cell. The reaction mechanism was investigated at the molecular level through density functional theory (DFT) calculation. The interface-modified Ag NPs provided stable *COOH intermediates during the reaction process, effectively achieving surface *CO enrichment. Besides, the presence of Ag NPs resulted in the generation of abundant Cu δ+ active species. The *CO migrated to the Cu δ+ active sites to accelerate the asymmetric coupling of *CO and *CHO, which significantly improved the FE of CO 2 electroreduction to ethanol. Our work offers a promising approach for designing Cu 2 Se-based nanowires electrocatalysts for CO 2 reduction with excellent activity and selectivity.
Electrochemical reduction of CO 2 to C 2+ products is a sustainable energy-driven pursuit for high added-value hydrocarbons. Tremendous efforts have been made to copper based electrocatalysts, which are well-known for producing C 2+ products. However, being short of well-defined catalysts with stable Cu δ+ electronic structure hinders its practical application and in-depth understanding. Herein, we developed a facile one-pot approach to prepare Cu δ+ -rich catalyst by doping phosphorus. Enhanced performance and tunable product selectivities are achieved due to the electron donor–acceptor interaction based on phosphorus content in series. C 2 hydrocarbons and alcohols are produced with high (~44.9%) selectivity, in which C 2 H 4 (30.7 ± 0.9%) is dominant at −1.6 V vs reversible hydrogen electrode (RHE). This P-Cu catalyst shows a significantly higher current density (57.2 mA cm −2 ) compared to pristine Cu. In addition, the favorable Cu δ+ is reserved during CO 2 RR contributing to a long-term stability. Experimental results and DFT calculations demonstrate that the Cu δ+ moiety facilitates the adsorption of carbon intermediates, C-C coupling and hence promotes the generation of C 2 H 4 energetically. The well-designed catalyst indicates the profit of electronic structure engineering in designing catalysts for multiple-step chemical conversions.
The use of renewable electricity to drive the electrocatalytic coupling of CO with nitrogen-containing organics offers a promising strategy for producing high-value chemicals. In this work, we conduct a systematic investigation of the coordination effect between iodide and copper oxide to generate Cu δ+ active sites. These Cu δ+ sites enable the electrosynthesis of dimethylacetamide from CO and dimethylamine. Through precise regulation of the electrode surface microenvironment, a dimethylacetamide Faradaic efficiency of 45.6% is achieved at a partial current density of 182.4 mA·cm -2 , with a production rate of 435.9 mmol·g cat. −1 ·h -1 and selectivity approaching 70%. Mechanistic studies reveal that specific adsorption of I - forms an iodide-enriched Cu 0 /Cu + interface that synergistically promotes dimethylacetamide formation by enhancing adsorption of ketene intermediates (*CCO) and facilitating C–N bonds formation. This anion-coordination interfacial engineering strategy demonstrates broad applicability for synthesizing various acetamide derivatives from CO 2 /CO and amine, providing a foundational framework for electrocatalytic C-N coupling in acetamide synthesis.