Ag-Cu aerogel for electrochemical CO conversion to CO.

The current strategy of electrocatalytic CO reduction reaction (eCORR) to generate useful chemicals and hydrocarbons is supposed to effectively mitigate the greenhouse effect. The practical application for eCORR in aqueous solutions, however, still was encumbered by its high overpotential, low activity and poor selectivity due to CO mass transfer and intermediate stability. Electrocatalytic materials with reduced overpotential and high efficiency and selectivity are exploited for further development. Herein, Ag and Cu precursors were co-reduced to generate Ag-Cu bimetallic aerogel after further freeze drying. Compared with Ag aerogel, the optimal AgCu can effectively decrease overpotential, improve selectivity and current density, and keep electrochemical stability. At -0.89 V vs. RHE, the Faraday efficiency reached 89.40% and the CO partial current density of -5.86 mA cm was obtained. The intrinsic property of metal aerogel (hydrophobic, hierarchical porous structure, conductivity), presence of rich grain boundaries and geometric effect and the introduction of Cu leading to improvement of adsorption between the catalyst and the *COOH intermediate in AgCu, contribute to the enhanced performance. Furthermore, the strategy of constructing metal aerogel will improve metal catalyst performance towards eCORR and pave way for further industrial applications.