Nanoscale Cu–Ag Heterostructures for CO2 Reduction to C2+ Products

Abstract

The electrochemical reduction of CO₂ (CO₂RR) to value-added chemicals represents a critical strategy for mitigating carbon emissions and promoting energy sustainability. This study focuses on enhancing the CO₂ reduction performance of copper-based catalysts through silver doping, with the specific objective of improving C₂₊ product selectivity and suppressing C₁ products. We report the delicate synthesis of three distinct CuAg Janus nanostructures using a coreduction method involving metal precursors for nucleation and growth. Compared to Cu NPs, CuAg Janus 1:0.02 exhibits significantly superior selectivity for both C₂H₄ (∼50%) and multicarbon products (∼70%) at −1.2 V vs RHE in CO₂RR. X-ray photoelectron spectroscopy (XPS) analysis reveals that the CuAg Janus nanostructure facilitates an electron transfer process, significantly influencing the catalytic activity and product selectivity of the CO₂ reduction reaction. In-situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy spectra indicate that CuAg Janus nanoparticles promote the formation of *CHO and *COCHO, which are key intermediates in the production of C₂H₄ and enhancement of C–C coupling. This study provides an effective strategy for designing advanced tandem catalysts, paving the way for the widespread application of the CO₂RR in addressing environmental and energy challenges.