催化学报 ›› 2025, Vol. 74: 120-129.DOI: 10.1016/S1872-2067(25)64679-1

• 论文 • 上一篇    下一篇

用杂原子调控Ni单原子催化剂的局部环境以实现高效CO2电还原

王刚a, Imran Muhammada, 阎慧敏a, 李隽a,b,*(), 王阳刚a,*()   

  1. a南方科技大学化学系, 广东省催化化学重点实验室, 广东深圳 518055
    b清华大学化学系, 稀土新材料教育部工程研究中心, 北京 100084
  • 收稿日期:2025-01-07 接受日期:2025-03-04 出版日期:2025-07-18 发布日期:2025-07-20
  • 通讯作者: *电子信箱: junli@tsinghua.edu.cn (李隽),wangyg@sustech.edu.cn (王阳刚).
  • 基金资助:
    国家自然科学基金(22373045);国家重点研发计划(2023YFA1509004);广东省“珠江”人才计划(2019QN01L353);国家自然科学基金单原子催化研究中心(22388102);深圳市科技委(JCYJ20210324103608023);深圳市科技委(KCXST20221021111207017);深圳市科技委(JCYJ20220818100410023)

Regulating the local environment of Ni single-atom catalysts with heteroatoms for efficient CO2 electroreduction

Gang Wanga, Imran Muhammada, Hui-Min Yana, Jun Lia,b,*(), Yang-Gang Wanga,*()   

  1. aDepartment of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
    bDepartment of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China
  • Received:2025-01-07 Accepted:2025-03-04 Online:2025-07-18 Published:2025-07-20
  • Contact: *E-mail: junli@tsinghua.edu.cn (J. Li), wangyg@sustech.edu.cn (Y.-G. Wang).
  • Supported by:
    National Natural Science Foundation of China(22373045);National Key Research and Development Program of China(2023YFA1509004);Guangdong “Pearl River” Talent Plan(2019QN01L353);NSFC Center for Single-Atom Catalysis(22388102);Science, Technology and Innovation Commission of Shenzhen Municipality(JCYJ20210324103608023);Science, Technology and Innovation Commission of Shenzhen Municipality(KCXST20221021111207017);Science, Technology and Innovation Commission of Shenzhen Municipality(JCYJ20220818100410023)

摘要:

电化学CO2还原反应(CO2RR)作为一种有效缓解环境问题和能源危机的技术路径, 其核心在于高效电催化剂的开发. 近年来, 分散在氮掺杂石墨烯载体上的Ni单原子催化剂(SAC)因其在CO2还原为CO过程中表现出的高选择性而受到广泛关注. 然而, Ni活性中心的化学吸附惰性导致其仅在较高过电位下才表现出电化学活性, 这严重制约了其实际应用. 因此, 探索如何提高Ni SAC的电催化CO2RR性能具有重要的研究意义.

本文提出了一种基于杂原子掺杂调控Ni SAC活性中心电子结构以提升CO2电还原性能的策略. 首先, 分别考察P和S杂原子在Ni1/N4C结构中的掺杂方式, 通过形成能计算筛选出两种相对稳定的掺杂构型: Ni1/PN4和Ni1/SN3C, 并利用热力学循环构建Pourbaix图, 证实了其在电化学反应条件下的结构稳定性. 其次, 通过电子结构分析发现, 在未掺杂的Ni1/N4C催化剂上, 由于Ni原子dz2轨道与COOH中间体π*轨道相互作用形成的反键轨道(dz2-π*)*位于费米能级以下, 导致COOH中间体的吸附稳定性较差; 而杂原子掺杂可以诱导Ni原子的dz2轨道显著上移, 使得反键轨道(dz2-π*)*移至费米能级以上, 从而削弱了反键轨道的电子占据, 增强了关键中间体COOH的吸附稳定性. 进一步在全显式溶剂模型, 采用限制性从头算分子动力学的方法, 对Ni1/SN3C催化剂上的CO2电还原反应机理进行了深入研究, 揭示了质子转移过程是该反应的决速步骤, 其动力学能垒随电势负移而降低. 最后通过微观动力学模型评估了电势依赖的CO2电还原反应速率, 并预测了S原子掺杂将使Ni SAC上的CO2还原起始电位从−0.88 V优化至−0.80 V vs. RHE, 催化活性显著提升.

综上所述, 本文通过原子尺度揭示了杂原子掺杂对金属中心电子结构及界面反应动力学的调控机制, 不仅为深入理解催化剂的构效关系提供了理论见解, 同时为高性能电催化剂的设计与优化提供了新的思路和方向.

关键词: Ni单原子催化剂, 杂原子掺杂, CO2电还原, 从头算分子动力学

Abstract:

The Ni single-atom catalyst dispersed on nitrogen doped graphene support has attracted much interest due to the high selectivity in electro-catalyzing CO2 reduction to CO, yet the chemical inertness of the metal center renders it to exhibit electrochemical activity only under high overpotentials. Herein, we report P- and S- doped Ni single-atom catalysts, i.e. symmetric Ni1/PN4 and asymmetric Ni1/SN3C can exhibit high catalytic activity of CO2 reduction with stable potential windows. It is revealed that the key intermediate *COOH in CO2 electroreduction is stabilized by heteroatom doping, which stems from the upward shift of the axial dz2 orbital of the active metal Ni atom. Furthermore, we investigate the potential-dependent free energetics and dynamic properties at the electrochemical interface on the Ni1/SN3C catalyst using ab initio molecular dynamics simulations with a full explicit solvent model. Based on the potential-dependent microkinetic model, we predict that S-atom doped Ni SAC shifts the onset potential of CO2 electroreduction from -0.88 to -0.80 V vs. RHE, exhibiting better activity. Overall, this work provides an in-depth understanding of structure-activity relationships and atomic-level electrochemical interfaces of catalytic systems, and offers insights into the rational design of heteroatom-doped catalysts for targeted catalysis.

Key words: Ni single-atom catalyst, Heteroatom doping, CO2 electroreduction, Ab initio molecular dynamics