Strained Lattice Gold-Copper Alloy Nanoparticles for Efficient Carbon Dioxide Electroreduction

Electrocatalytic conversion of carbon dioxide (CO₂) into specific renewable fuels is an attractive way to mitigate the greenhouse effect and solve the energy crisis. Au_nCu_100-n/C alloy nanoparticles (Au_nCu_100-n/C NPs) with tunable compositions, a highly active crystal plane and a strained lattice were synthesized by the thermal solvent co-reduction method. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) results show that Au_nCu_100-n/C catalysts display a subtle lattice strain and dominant (111) crystal plane, which can be adjusted by the alloy composition. Electrochemical results show that Au_nCu_100-n/C alloy catalysts for CO₂ reduction display high catalytic activity; in particular, the Faradaic efficiency of Au₇₅Cu₂₅/C is up to 92.6% for CO at -0.7 V (vs. the reversible hydrogen electrode), which is related to lattice shrinkage and the active facet. This research provides a new strategy with which to design strong and active nanoalloy catalysts with lattice mismatch and main active surfaces for CO₂ reduction reaction.