催化学报

催化学报 ›› 2022, Vol. 43 ›› Issue (7): 1860-1869.DOI: 10.1016/S1872-2067(21)64011-1

• 论文 • 上一篇    下一篇

氧官能团MXenes用于电催化合成氨的理论筛选

高怡静a,b,c,†, 张世杰b,†, 孙翔b,†, 赵伟b, 卓涵b, 庄桂林b, 王式彬b, 姚子豪b, 邓声威b, 钟兴b, 魏中哲b, 王建国b,*()   

  1. a浙江师范大学含氟新材料研究所, 浙江省含氟专用品绿色合成与应用工程实验室, 浙江金华321004
    b浙江工业大学化工学院, 工业催化研究所, 绿色化学合成国家重点实验室培育基地, 浙江杭州310032
    c浙江师范大学物理化学研究所, 先进催化材料教育部重点实验室, 浙江金华321004
  • 收稿日期:2021-10-22 接受日期:2021-12-11 出版日期:2022-07-18 发布日期:2022-05-20
  • 通讯作者: 王建国
  • 作者简介:第一联系人：

    †共同第一作者

  • 基金资助:
    国家自然科学基金(21878272);国家自然科学基金(21625604);山东省自然科学基金(ZR2020ZD35)

Computational screening of O-functional MXenes for electrocatalytic ammonia synthesis

Yijing Gaoa,b,c,†, Shijie Zhangb,†, Xiang Sunb,†, Wei Zhaob, Han Zhuob, Guilin Zhuangb, Shibin Wangb, Zihao Yaob, Shengwei Dengb, Xing Zhongb, Zhongzhe Weib, Jian-guo Wangb,*()   

  1. aZhejiang Engineering Laboratory for Green Syntheses and Applications of Fluorine-Containing Specialty Chemicals, Institute of Advanced Fluorine-Containing Materials, Zhejiang Normal University, Jinhua 321004, Zhejiang, China
    bInstitute of Industrial Catalysis, College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, Zhejiang, China
    cKey Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China
  • Received:2021-10-22 Accepted:2021-12-11 Online:2022-07-18 Published:2022-05-20
  • Contact: Jian-guo Wang
  • About author:First author contact:

    †Contributed equally to this work.

  • Supported by:
    National Natural Science Foundation of China(21878272);National Natural Science Foundation of China(21625604);Natural Science Foundation of Shandong Province(ZR2020ZD35)

RichHTML

200

PDF

230

摘要：

电催化合成氨技术以绿色可再生的电能为驱动力, 通过在室温条件下改变外加电压来克服速控步能垒, 被认为是一种取代哈伯工艺的潜在选择. 然而, 该技术存在法拉第效率较低、氨气产率不高等问题. 因此, 设计高效的电合成氨催化剂是目前亟待解决的关键问题. 氧官能团的二维过渡金属碳化物和氮化物(MXenes)由于具有独特的几何结构、高导电性和表面易调变等特点, 在全水解、碳转化、氧还原或固氮等电催化过程中应用十分广泛. 其中, 表面氧官能团不饱和覆盖的MXenes材料的电催化合成氨性能较好, 这是因为适量的氧空位能够调节活性中心的电荷分布, 从而优化关键中间体的结合强度; 同时, 氧空位的存在为反应提供了足够的活性位点. 然而, 氧官能团MXenes家族庞大, 种类众多, 如何从中筛选出合适的合成氨电催化剂尚且缺乏理论指导.

本文设计了一系列氧官能团的二维过渡金属碳化物和氮化物(MXenes)作为合成氨电催化剂, 并通过密度泛函理论从稳定性、选择性和活性角度出发提出了一套较完善的筛选流程. 以纯MXenes表面覆盖17/18氧官能团所需的极限电位来判断氧官能团MXenes的稳定性. 通过对催化剂上氮气分子和氢原子的吸附行为进行比较来证明其选择性. 通过比较潜在热力学决速步的吉布斯自由能(包括GN2-NNH, GNH-NH2和GNH2-NH3)快速获得反应所需的极限电位, 可以快速筛选出最佳催化剂. 在此基础上, 通过吉布斯自由能计算, 完整分析了Nb3C2Ox上电催化合成氨的反应机理并利用催化性能来验证筛选的准确性. 计算结果表明, Nb3C2Ox催化剂上的热力学决速步为*NH2加氢, 吉布斯自由能仅上升了0.45 eV, 与筛选结果一致. 此外, 结合套索算法, 回归了氧官能团MXenes电催化合成氨性能Gx的表达式, 探寻了催化活性来源. 同时, 由吸附能组成的描述符被证明是描述热力学决速步吉布斯自由能的重要变量.

关键词: 电催化合成氨, 氧官能团MXenes, 密度泛函理论, 套索算法, 吉布斯自由能

Abstract:

The nitrogen reduction reaction (NRR) using new and efficient electrocatalysts is a promising alternative to the traditional Haber-Bosch process. Nevertheless, it remains a challenge to design efficient catalysts with improved catalytic performance. Herein, various O-functional MXenes were investigated as NRR catalysts by a combination of density functional theory calculations and least absolute shrinkage and selection operator (LASSO) regression. Nb3C2OX has been regarded as a promising catalyst for the NRR because of its stability, activity, and selectivity. The potential-determining step is *NH2 hydrogenation to *NH3 with a limiting potential of -0.45 V. Furthermore, via LASSO regression, the descriptors and equations fitting the relationship between the properties of O-functional MXenes and NRR activity have been proposed. This work not only provides a rational design strategy for catalysts but also provides machine learning data for further investigation.

Key words: Electrocatalytic ammonia synthesis, O-functional MXenes, Density functional theory, Least absolute shrinkage and selection operator regression, Gibbs free energy