Zhang Yue, Mo Yirong, Cao Zexing
State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemistry Engineering, Xiamen University, Xiamen 361005, China.
Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, North Carolina 27401, United States.
ACS Appl Mater Interfaces. 2022 Jan 12;14(1):1002-1014. doi: 10.1021/acsami.1c20230. Epub 2021 Dec 22.
Developing efficient and inexpensive main group catalysts for CO conversion and utilization has attracted increasing attention, as the conversion process would be both economical and environmentally benign. Here, based on the main group element Al, we designed several heterogeneous frustrated Lewis acid/base pair (FLP) catalysts and performed extensive first-principles calculations for the hydrogenation of CO. These catalysts, including Al@N-Gr-1, Al@N-Gr-2, and Al@CN, are composed of a single Al atom and two-dimensional (2D) N-doped carbon-based materials to form frustrated Al/C or Al/N Lewis acid/base pairs, which are all predicted to have high reactivity to absorb and activate hydrogen (H). Compared with Al@N-Gr-1, both Al@N-Gr-2 and Al@CN, especially Al@N-Gr-2, containing Al/N Lewis pairs exhibit better catalytic activity for CO hydrogenation with lower activation energies. CO hydrogenation on the three catalysts prefers to go through a three-step mechanism, i.e., the heterolytic dissociation of H, followed by the transfer of the hydride near Al to CO, and finally the activation of a second H molecule. Other IIIA group element (B and Ga)-embedded N-Gr-2 materials (B@N-Gr-2 and Ga@N-Gr-2) were also explored and compared. Both Al@N-Gr-2 and Ga@N-Gr-2 show higher catalytic activity for CO hydrogenation to HCOOH than B@N-Gr-2. However, the CO hydrogenation path on Ga@N-Gr-2 tends to follow a two-step mechanism, including H dissociation and subsequent hydrogen transfer. The present study provides a potential solution for CO hydrogenation by designing novel and effective FLP catalysts based on main group elements.
开发高效且廉价的主族元素催化剂用于一氧化碳（CO）的转化和利用已引起越来越多的关注，因为该转化过程在经济和环境方面都具有优势。在此，基于主族元素铝（Al），我们设计了几种非均相受阻路易斯酸碱对（FLP）催化剂，并对CO加氢反应进行了广泛的第一性原理计算。这些催化剂，包括Al@N-Gr-1、Al@N-Gr-2和Al@CN，由单个Al原子和二维（2D）氮掺杂碳基材料组成，形成受阻的Al/C或Al/N路易斯酸碱对，预计它们对吸收和活化氢（H）都具有高反应活性。与Al@N-Gr-1相比，Al@N-Gr-2和Al@CN，特别是含有Al/N路易斯对的Al@N-Gr-2，在较低活化能下对CO加氢表现出更好的催化活性。三种催化剂上的CO加氢反应倾向于通过三步机理进行，即H的异裂解离，随后Al附近的氢化物转移至CO，最后活化第二个H分子。还探索并比较了其他嵌入IIIA族元素（B和Ga）的N-Gr-2材料（B@N-Gr-2和Ga@N-Gr-2）。Al@N-Gr-2和Ga@N-Gr-2对CO加氢生成甲酸（HCOOH）的催化活性均高于B@N-Gr-2。然而，Ga@N-Gr-2上的CO加氢路径倾向于遵循两步机理，包括H解离和随后的氢转移。本研究通过设计基于主族元素的新型高效FLP催化剂，为CO加氢提供了一种潜在的解决方案。
