催化学报 ›› 2022, Vol. 43 ›› Issue (7): 1830-1841.DOI: 10.1016/S1872-2067(21)64027-5

• 论文 • 上一篇    下一篇

MXene负载的非贵金属单原子催化剂催化CO氧化反应

朱纯a,b, 梁锦霞a,b,*(), 王阳刚b, 李隽b,c,#()   

  1. a贵州大学化学与化工学院, 贵州贵阳550025
    b南方科技大学化学系, 广东深圳518055
    c清华大学化学系, 有机光电子与分子工程教育部重点实验室, 北京100084
  • 收稿日期:2021-12-12 接受日期:2021-12-30 出版日期:2022-07-18 发布日期:2022-05-20
  • 通讯作者: 梁锦霞,李隽
  • 基金资助:
    国家自然科学基金(21963005);国家自然科学基金(21763006);国家自然科学基金(22033005);陕西省催化重点实验室开放课题(SXKLC-2017-01);广东省催化重点实验室(2020B121201002);广东省“珠江人才计划”(2019QN01L353);贵州大学自然科学基金([2021]40);贵州大学自然科学基金([2020]32)

Non-noble metal single-atom catalyst with MXene support: Fe1/Ti2CO2 for CO oxidation

Chun Zhua,b, Jin-Xia Lianga,b,*(), Yang-Gang Wangb, Jun Lib,c,#()   

  1. aSchool of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, Guizhou, China
    bDepartment of Chemistry, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
    cDepartment of Chemistry, Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China
  • Received:2021-12-12 Accepted:2021-12-30 Online:2022-07-18 Published:2022-05-20
  • Contact: Jin-Xia Liang, Jun Li
  • About author:Jun Li (Department of Chemistry, Tsinghua University) was invited to join the 5th and 6th Editorial Board of Chin. J. Catal. He received a PhD degree from Chinese Academy of Sciences in 1992 and then did postdoctoral research in Siegen University (Germany) and The Ohio State University (USA) from 1993 to 1997. He then worked as a Research Scientist, Senior Research Scientist, and Chief Scientist at The Ohio State University and Pacific Northwest National Laboratory (USA). He later joined the faculty at Tsinghua University as a ChangJiang Chair Professor. He works in the field of relativistic quantum chemistry, computational catalysis and cluster science, with more than 400 publications and some 40000 citations.
  • Supported by:
    National Science Foundation of China(21963005);National Science Foundation of China(21763006);National Science Foundation of China(22033005);Open Fund of Shaanxi Key Laboratory of Catalysis(SXKLC-2017-01);Guangdong Provincial Key Laboratory of Catalysis(2020B121201002);Guangdong “Pearl River” Talent Plan(2019QN01L353);Natural Science Foundation of Guizhou University([2021]40);Natural Science Foundation of Guizhou University([2020]32)

摘要:

单原子催化剂是一类新型的环境友好催化材料, 在能源有效利用和环境保护中发挥着至关重要的作用. 发展廉价高效的贵金属催化剂具有十分重要的科学意义和实用价值. 近年来, 非贵金属部分或者全部取代贵金属的研究也备受关注, 成为催化领域的研究热点之一. MXene是由MAX相刻蚀得到的新型类石墨烯结构. MAX相的分子式为Mn+1AXn (n = 1, 2, 3), 其中M代表前过渡金属, A代表主族元素, X代表C和/或N元素. 由于M‒X具有较强的化学键能, A具有较活泼的化学活性, 因此, 可以通过选择性刻蚀作用将A从MAX相中移除, 从而得到类石墨烯的2D结构—MXene. 各类MXenes二维材料因具有广泛的应用价值和较好的物理化学性能而引起了人们的广泛关注, 尤其在单原子催化方面, MXenes表现出巨大的应用潜力.

本文选取氧功能化的Ti2C (Ti2CO2) MXene二维材料为载体, 系统研究了其负载的金属单原子催化剂(SACs)的稳定性和催化活性. 通过筛选周期表第8‒11族过渡金属M1/Ti2CO2 (M = Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, Au), 筛选出了一种新的非贵金属单原子催化剂Fe1/Ti2CO2, 发现其对CO氧化反应具有极高的催化活性. 基于密度泛函理论(DFT)计算, 使用VASP从头算模拟软件对上述体系进行了结构优化以及性质的计算, 选取了广义梯度近似(GGA)中的PBE泛函, 采用投影缀加平面波(PAW)方法描述体系中电子-离子的相互作用. 计算结果表明, O2和CO分子易于在Fe1/Ti2CO2表面的Fe1单原子上吸附活化. 基于O2和CO分子不同的吸附构型, 对Fe1/Ti2CO2催化CO氧化包括Langmuir-Hinshelwood (L-H), Eley-Rideal (E-R), Mars-van Krevelen (MvK), 三分子Eley-Rideal (TER)和三分子Langmuir-Hinshelwood (TLH)可能的五种反应机理进行了理论研究. 结果表明, L-H, E-R, Mvk, TER和TLH反应的决速步骤均为形成第一个CO2分子的过程, 其活化能分别为0.95, 0.77, 2.27, 0.98和0.20 eV, 而第二个CO2分子的生成反应势垒都很低. 根据计算得到的不同反应路径及其反应能, TLH机理的决速步势垒低至0.20 eV, 表明CO氧化在Fe1/Ti2CO2表面的反应极易通过TLH机理进行. 另外, 对反应过程中Fe单原子价态的分析发现, 铁单原子的高反应活性与其在CO氧化反应过程中的价态变化促进反应过程中的电子转移有关. 上述研究表明, Fe1/Ti2CO2 MXene是一类非常有潜力的二维非贵金属低温单原子催化剂材料.

关键词: 单原子催化剂, 密度泛函理论, Ti2CO2 MXene, CO氧化反应

Abstract:

MXenes have attracted considerable attention owing to their versatile and excellent physicochemical properties. Especially, they have potential applications as robust support for single atom catalysts. Here, quantum chemical studies with density functional theory are carried out to systematically investigate the geometries, stability, electronic properties of oxygen functionalized Ti2C (Ti2CO2) supported single-atom catalysts M1/Ti2CO2 (M = Fe, Co, Ni, Cu Ru, Rh, Pd, Ag Os, Ir, Pt, Au). A new non-noble metal SAC Fe1/Ti2CO2 has been found to show excellent catalytic performance for low-temperature CO oxidation after screening the group 8-11 transition metals. We find that O2 and CO adsorption on Fe1 atom of Fe1/Ti2CO2 is favorable. Accordingly, five possible mechanisms for CO oxidation on this catalyst are evaluated, including Eley-Rideal, Langmuir-Hinshelwood, Mars-van Krevelen, Termolecular Eley-Rideal, and Termolecular Langmuir-Hinshelwood (TLH) mechanisms. Based on the calculated reaction energies for different pathways, Fe1/Ti2CO2 shows excellent kinetics for CO oxidation via TLH mechanism, with distinct low-energy barrier (0.20 eV) for the rate-determining step. These results demonstrate that Fe1/Ti2CO2 MXene is highly promising 2D materials for building robust non-noble metal catalysts.

Key words: Single-atom catalyst, Density functional theory, Ti2CO2 MXene, CO oxidation