催化学报 ›› 2023, Vol. 50: 249-259.DOI: 10.1016/S1872-2067(23)64476-6

• 论文 • 上一篇    下一篇

金属掺杂SnO2电化学还原CO2制甲酸的计算研究

刘赵春a, 宗雪b, Dionisios G. Vlachosb, Ivo A. W. Filota,*(), Emiel J. M. Hensena,*()   

  1. a埃因霍温理工大学化学工程与化学系, 无机材料化学实验室, 荷兰
    b特拉华大学特拉华能源研究所, 化学与生物分子工程系, 美国
  • 收稿日期:2023-04-26 接受日期:2023-06-25 出版日期:2023-07-18 发布日期:2023-07-25
  • 通讯作者: *电子信箱: I.A.W.Filot@tue.nl (I. A. W. Filot), e.j.m.hensen@tue.nl (E. J. M. Hensen).

A computational study of electrochemical CO2 reduction to formic acid on metal-doped SnO2

Zhaochun Liua, Xue Zongb, Dionisios G. Vlachosb, Ivo A. W. Filota,*(), Emiel J. M. Hensena,*()   

  1. aLaboratory of Inorganic Materials Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
    bDepartment of Chemical and Biomolecular Engineering, The Delaware Energy Institute, University of Delaware, 221 Academy St., Newark, DE 19716, USA
  • Received:2023-04-26 Accepted:2023-06-25 Online:2023-07-18 Published:2023-07-25
  • Contact: *E-mail: I.A.W.Filot@tue.nl (I. A. W. Filot), e.j.m.hensen@tue.nl (E. J. M. Hensen).

摘要:

CO2电化学还原为甲酸(HCOOH)作为可再生氢的液体载体, 有助于可再生能源的转变. 本文使用密度泛函理论和微观动力学模拟研究了SnO2电极上CO2高效催化还原为HCOOH的要求. 表面羟基化是实现高活性的先决条件, 预测的电流密度与实验值的趋势相同. 所得到的羟基化表面对HCOOH的产生具有高选择性, 析氢反应的贡献可以忽略不计. 机理研究结果表明, 反应首先将吸附的CO2加氢为羧酸盐(COOH), 然后进一步加氢获得所需产物. 通过采用常用元素(Bi, Pd, Ni和Cu)对表面进行掺杂, 确定Bi掺杂可以显著提高电流密度. 根据该机理中的两个关键步骤建立了Brønsted-Evans-Polanyi关系. 总之, 羧酸盐的形成是速率控制步骤. 将两个质子化步骤的自由能作为两个描述符, 分析了CO2还原活性, 结果表明Bi掺杂SnO2电极具有最高活性.

关键词: CO2还原, 甲酸, SnO2, 助剂, 密度泛函理论

Abstract:

Electrochemical reduction of CO2 to formic acid (HCOOH) can contribute to the renewable energy transition as a liquid carrier of renewably hydrogen. Here, we investigated the catalytic requirements of SnO2 electrodes for efficient CO2 reduction to HCOOH using density functional theory and microkinetics simulations. Hydroxylation of the surface is a prerequisite to achieve a high activity with predicted current densities in agreement with experiment. The resulting surface is selective to HCOOH production with a negligible contribution of the hydrogen evolution reaction. Mechanistically, it is found that the reaction proceeds via hydrogenation of adsorbed CO2 to carboxylate (COOH), which is then further hydrogenated to the desired product. Doping of the surface by commonly used elements (Bi, Pd, Ni and Cu) identifies Bi as the preferred promoter to substantially improve the current density. Brønsted-Evans-Polanyi relations are established for the two key steps in the mechanism. Overall, carboxylate formation is the rate-controlling step. The CO2 reduction activity is analyzed in terms of two descriptors, namely the free energies for the two protonation steps, showing that Bi presents the highest activity.

Key words: CO2 reduction, Formic acid, SnO2, Promoters, Density functional theory