离子液体修饰Cu2O疏水界面促进电催化CO2还原生成多碳产物

The ionic liquid-modified Cu2O hydrophobic interface promotes the electroreduction CO2 to multi-carbon products

中文关键词: 电催化还原二氧化碳  离子液体  多碳产物  正丙醇

英文关键词: electrocatalytic reduction of CO2, ionic liquids, multi-carbon products, n-propanol

中文摘要:

      电催化二氧化碳（CO2）还原技术可以将CO2转化为高附加值多碳（C2+）产物，对实现碳中和与资源循环具有重要意义。然而，电极表面CO2传质缓慢和C-C耦合困难导致C2+产物的选择性低。本研究采用离子液体（IL）界面修饰策略构建疏水性Cu2O基复合催化剂（Cu2O/IL）。利用IL的阳离子基团稳定*CO关键中间体，协同Cu的C-C偶联能力，实现二者协同催化促进C2+产物转化。实验结果表明，在优化电流密度和IL修饰量的条件下，Cu2O/IL催化剂在流动池反应器中表现出显著增强的C2+产物选择性。在200-500 mA cm-2的高电流密度范围内，C2+产物的总法拉第效率最高达到80.1%，其中C3产物正丙醇法拉第效率最高达到7.65%，较未修饰催化剂提升1.5倍。通过实验及表征分析，揭示IL修饰层通过调控电极表面微环境、稳定*CO中间体与促进C-C耦合的协同作用机制。该研究为设计高效CO2电还原催化剂提供了新的界面工程策略与理论支持。

英文摘要:

      Electrocatalytic carbon dioxide (CO2) reduction technology can convert CO2 into high-value-added multi-carbon (C2+) products, which is crucial for achieving carbon neutrality and sustainable resource utilization. However, slow CO2 mass transfer on electrode surface and C-C coupling kinetics lead to low selectivity of C2+ products. In this study, an ionic liquid (IL) interface modification strategy was employed to construct a hydrophobic Cu2O-based composite catalyst (Cu2O/IL). The hydrophobic property of IL was utilized to stabilize *CO intermediate by its cationic group, promoting C-C coupling for C2+ products generation. Experimental results demonstrated that the Cu2O-IL catalysts exhibited significantly enhanced C2+ products selectivity in a flow cell under different current densities and IL modification amounts. Within the high current density range of 200-500 mA cm-2, the total FE of C2+ products achieved 80.1%, with the C3 product n-propanol FE achieving 7.65% which was a 1.5-fold enhancement over the unmodified catalyst. Experiments and characterization analysis revealed that the IL modification stabilized the *CO intermediate and promoted the C-C coupling kinetics. This work provides a new interface engineering strategy for design of efficient CO2 electroreduction catalysts.