Electronic Structure Tuning in Cu–Co Dual Single Atom Catalysts for Enhanced COOH* Spillover and Electrocalytic CO₂ Reduction Activity

Abstract

AbstractThe development of efficient electrocatalysts for CO2 reduction to CO is challenging due to competing hydrogen evolution and intermediate over‐stabilization. In this study, a Cu–Co dual single‐atom catalyst (CuCo‐DSAC) anchored on carbon black was synthesized via scalable pyrolysis. The catalyst achieves 98.5% CO Faradaic efficiency at 500 mA cm−2, maintaining > 95% selectivity across a 400 mV window with < 6% decay over 48 h, which is superior to the corresponding single‐atom control samples. In situ spectroscopy and DFT calculations reveal a synergistic mechanism: Co sites activate CO2 and stabilize *COOH intermediates, while adjacent Cu sites facilitate CO desorption by lowering the energy barrier through charge redistribution. This dynamic buffer system mitigates active‐site blocking and suppresses HER by weakening H adsorption. The electronic interplay between Cu and Co optimizes intermediate energetics, enabling industrial‐level performance. This work demonstrates the potential of tailored dual‐site architectures for complex electrocatalytic processes, offering a promising approach to overcoming traditional limitations.