物理化学学报

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表面重构调控的氧化物衍生铜电催化CO还原生成乙烯的机理研究

尹婷婷1, 孙一凡1, 吴德印2, 赵刘斌1   

  1. 1 西南大学化学化工学院化学系, 重庆 400715;
    2 固体表面物理化学国家重点实验室, 化学化工学院化学系, 厦门大学, 福建 厦门 361005
  • 收稿日期:2026-07-11 修回日期:2026-08-03 录用日期:2026-08-06
  • 通讯作者: 吴德印, 赵刘斌 E-mail:dywu@xmu.edu.cn;lbzhao@swu.edu.cn
  • 基金资助:
    本工作得到了固体表面物理化学国家重点实验室(厦门大学，编号 202421)开放基金、重庆市自然科学基金(CSTB2023NSCQ-MSX0768)的资助。

Mechanistic study of CO electroreduction to ethylene on oxide-derived copper controlled by surface reconstruction

Tingting Yin1, Yifan Sun1, Deyin Wu2, Liubin Zhao1   

  1. 1 Department of Chemistry, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China;
    2 State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, China
  • Received:2026-07-11 Revised:2026-08-03 Accepted:2026-08-06
  • Contact: Deyin Wu, Liubin Zhao E-mail:dywu@xmu.edu.cn;lbzhao@swu.edu.cn

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摘要： 理解表面结构演化与反应动力学的关系对于设计高性能CO2/CO电还原催化剂至关重要。本工作通过逐层去除氧化亚铜催化剂的晶格氧，构建了四种氧化物衍生铜(OD-Cu)表面。结合微观动力学模型，建立了从CO转化至C2产物的完整反应网络。计算结果表明，各OD-Cu表面在不同施加电位下均可自主选择最有利的偶联机制。具体而言，ECE和EEC机制在Cu2O-0L和Cu2O-1L表面上占据主导。在Cu2O-2L和Cu2O-3L表面上，由于*CO二聚的能垒显著降低至0.24和0.08 eV，使偶联转向CEE机制。在所考虑的C2路径中，含氧中间体的O-H氢化动力学优于C-H氢化，从而促进C-O键断裂并驱动反应通量向脱氧路径汇聚，最终导致乙烯生成占据主导地位。在-0.2 V至-1.2 V的电位范围内，CO还原经历了从电化学控制到脱附控制的动力学转变。值得注意的是，Cu2O-2L表面在吸附C-C偶联形成的C2中间体后发生重构，形成的无序、非均匀结构，显著降低了乙烯脱附能垒，并将脱附控制动力学的触发延迟至更负的电位，从而诱导乙烯生成速率随电位呈指数级增长，相较原始Cu2O表面实现了约六个数量级的提升。本研究从偶联选择性、反应机理及表面重构协同作用的角度，系统揭示了OD-Cu上C2产物生成的原子尺度机制。这些发现为设计高选择性C2电催化剂提供了理论指导。

关键词: 密度泛函理论, CO还原反应, 微观动力学模型, C-C偶联机制, 氧化物衍生铜, 表面重构

Abstract: Understanding the correlation between surface structure evolution and reaction kinetics is pivotal for designing high-performance CO2/CO electroreduction catalysts. In this work, four oxide-derived copper (OD-Cu) surfaces were constructed by progressively removing lattice oxygen from Cu2O. Combined with microkinetic modeling, a comprehensive reaction network from CO conversion to C2 products was established. Computational results indicate that each OD-Cu surface can autonomously select the most favorable coupling mechanism under applied potentials. Specifically, the ECE and EEC mechanisms dominate on the Cu2O-0L and Cu2O-1L surfaces. On the Cu2O-2L and Cu2O-3L surfaces, the barrier for *CO dimerization decreases significantly to 0.24 and 0.08 eV, shifting the coupling toward the CEE mechanism. Among the considered C2 pathways, O-H hydrogenation of oxygenated intermediates is kinetically favored over C-H hydrogenation. This facilitates C-O bond cleavage and drives the reaction flux toward the deoxygenation pathway, ultimately leading to ethylene dominance. Within the potential range of -0.2 to -1.2 V, CO reduction undergoes a kinetic transition from electrochemical control to desorption control. Notably, the Cu2O-2L surface undergoes reconstruction upon adsorbing the C2 intermediate formed via C-C coupling. This process creates a disordered, heterogeneous structure that significantly lowers the ethylene desorption energy barrier and delays the onset of desorption control kinetics to more negative potentials. Consequently, the ethylene production rate increases exponentially with potential, achieving an enhancement of approximately six orders of magnitude compared to the pristine Cu2O surface. This study systematically reveals the atomic-scale mechanisms of C2 product formation on OD-Cu from the perspectives of coupling selectivity, reaction mechanism, and surface reconstruction. These findings provide theoretical guidance for designing highly selective C2 electrocatalysts.

Key words: Density functional theory, CO reduction reaction, Microkinetic model, C-C coupling mechanisms, Oxide-derived copper, Surface reconstruction