Evaluating the Impact of Doping and Interface Engineering on CO2-to-CO Conversion Selectivity in Cu-Based Electrochemical Catalysts

Doping and interface engineering are both pivotal strategies for enhancing the selectivity of CO 2 reduction catalysts. However, as these strategies have often been explored independently, the question of which is more effective or whether their effects can be synergistically combined remains open. Given that doping and interfaces serve as crystallographic defects, they can be engineered to coexist within the same crystal structure. In this study, we strategically introduced both defects into a copper catalyst by modulating the indium content during crystal growth. Our investigation into the electrochemical performance of these catalysts for CO conversion reveals that while doping consistently enhances conversion selectivity, the presence of Cu/In interfaces disrupts this trend. The most promising catalyst, with 3% indium doping, demonstrated an impressive CO selectivity of 95.38±1.5% and a partial current density of -2.25 mA cm - ² at -0.8 V vs. Reversible Hydrogen Electrode (RHE). This research provides critical insights into the complex interplay between doping and interface engineering, offering a new pathway for the rational design of highly selective CO 2 reduction catalysts.