DataSheet1_Exploring the mechanistic role of alloying elements in copper-based electrocatalysts for the reduction of carbon dioxide to methane.docx

The promise of electrochemically reducing excess anthropogenic carbon dioxide into useful chemicals and fuels has gained significant interest. Recently, indium–copper (In–Cu) alloys have been recognized as prospective catalysts for the carbon dioxide reduction reaction (CO2RR), although they chiefly yield carbon monoxide. Generating further reduced C1 species such as methane remains elusive due to a limited understanding of how In–Cu alloying impacts electrocatalysis. In this work, we investigated the effect of alloying In with Cu for CO2RR to form methane through first-principles simulations. Compared with pure copper, In–Cu alloys suppress the hydrogen evolution reaction while demonstrating superior initial CO2RR selectivity. Among the alloys studied, In7Cu10 exhibited the most promising catalytic potential, with a limiting potential of −0.54 V versus the reversible hydrogen electrode. Analyses of adsorbed geometries and electronic structures suggest that this decreased overpotential arises primarily from electronic perturbations around copper and indium ions and carbon–oxygen bond stability. This study outlines a rational strategy to modulate metal alloy compositions and design synergistic CO2RR catalysts possessing appreciable activity and selectivity.

将过量人为源二氧化碳电化学还原为高附加值化学品与燃料的愿景，已引发学界广泛关注。近期，铟铜（In–Cu）合金被认为是二氧化碳还原反应（CO2RR）的极具潜力的催化剂，不过该类催化剂的主要产物仍为一氧化碳。由于对In–Cu合金化如何影响电催化过程的认知不足，合成甲烷等深度还原的C1物种仍颇具挑战。本研究通过第一性原理模拟，探究了铟与铜合金化用于CO2RR生成甲烷的效果。与纯铜相比，In–Cu合金可抑制析氢反应，同时展现出更优异的初始CO2RR选择性。在所研究的合金中，In7Cu10表现出最具潜力的催化性能，其相对于可逆氢电极的极限电位为-0.54 V。吸附构型与电子结构分析表明，该过电位降低主要源于铜、铟离子周围的电子扰动以及碳氧键稳定性。本研究提出了一种调控金属合金组分、设计兼具可观活性与选择性的协同型CO2RR催化剂的合理策略。