Synthesis of AuX (X = Ni, Ga, Mo, Zn, and Cr) Alloy Aerogels as High-Performance Electrocatalytic CO₂ Reduction Reaction Catalysts

Abstract

Electrocatalytic CO2 reduction reaction (eCO2RR) into value-added chemicals is highly desirable to mitigate the global warming effect and energy crisis. Metal aerogels, as featured by a self-supporting structure, large specific surface area, outstanding conductivity, and a hierarchical porous structure, are ideal electrocatalysts in eCO2RR. Herein, we report a simple and general strategy for constructing a series of Au-based alloy aerogels which contain Au with another metal including Ga, Ni, Mo, Zn, and Cr, respectively. For the first time, the electrocatalytic activities of AuGa aerogels, AuNi aerogels, and AuMo aerogels for CO2RR were studied in detail. The resultant Au81Ga19 aerogel achieves a 95.2% Faradaic efficiency (FE) at −1.16 V versus reversible hydrogen (vs RHE) in H-cells. Impressively, a total 99.4% FE for C1 products (CO + HCOOH) with a current density of 100 mA cm–2 at −0.6 V vs RHE and a large current density of 228 mA cm–2 can be achieved at −0.9 V with a 72.3% FE for the C1 product in a flow cell. Electrochemical characterization and theoretical calculations further revealed that the outstanding performance of the Au-based aerogels was derived from the large specific surface area, abundant grain boundaries, low interfacial charge transfer resistance, and synergetic effect. Overall, this study provides a promising alternative to engineer alloy aerogel electrocatalysts for highly efficient CO2 electroreduction.

Efficient Electrosynthesis of Urea over Single‐Atom Alloy with Electronic Metal Support Interaction

“…The lattice spacing of 0.326 nm corresponds to (111) planes of CeO 2 , and 0.203 nm and 0.235 nm associated with (200) and (111) planes of Au respectively. [16,17] Corresponding selected-area electron diffraction (SAED) pattern (Figure S3) can be indexed to crystal planes of Au, implying single-atom Cu sites are highly disperse over Cu 1 Au 8 @CeO 2 . Randomly magnified image indicates atomically dispersed Cu sites (marked by yellow circles, Figure 1c) are isolated by surrounding Au atoms, which is originated from Au NPs with atomic vacancies formed by bonding with neighboring Cu atoms.…”

“…Aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) image (Figure 1b) of Cu 1 Au 8 @CeO 2 further validates CuAu SAA with an average size of ~5 nm is well‐anchored onto CeO 2 . The lattice spacing of 0.326 nm corresponds to (111) planes of CeO 2 , and 0.203 nm and 0.235 nm associated with (200) and (111) planes of Au respectively [16,17] . Corresponding selected‐area electron diffraction (SAED) pattern (Figure S3) can be indexed to crystal planes of Au, implying single‐atom Cu sites are highly disperse over Cu 1 Au 8 @CeO 2 .…”

Surface Coordination Environment Engineering on PtxCu1–x Alloy Catalysts for the Efficient Photocatalytic Reduction of CO2 to CH4

“…In summary, the introduction of coalloy catalysts can broaden the light absorption spectrum of TiO 2 support and provide diverse adsorption and activation sites for CO 2 , accordingly promoting the photocatalytic reduction of CO 2 . Composition regulation of metal alloy is a strategy to design the catalysts with high active sites and the desired surface and thus reducing the recombination of charge carriers and enhancing the photocatalytic activity. − However, the impact of alloy coordination environments on the CO 2 adsorption mode at the atomic level is still ambiguous.…”