Regulating the coordination environment of Ru single-atom catalysts and unravelling the reaction path of acetylene hydrochlorination

• Published in: Green energy & environment 2023-08, Vol.8 (4), p.1141-1153
• Main Authors: Yang, Yang, Zhao, Chaoyue, Qiao, Xianliang, Guan, Qingxin, Li, Wei
• Format: Article
• Language: English
• Subjects: Acetylene hydrochlorination; Coordination environment; DFT calculations; Ru-based catalyst; Single-atom catalyst
• ISSN: 2468-0257; 2468-0257
• DOI: 10.1016/j.gee.2022.01.006

In this work, DFT calculations were used firstly to simulate the nitrogen coordinated metal single-atom catalysts (M-Nx SACs, M = Hg, Cu, Au, and Ru) to predict their catalytic activities in acetylene hydrochlorination. The DFT results showed that Ru-Nx SACs had the best catalytic performance among the four catalysts, and Ru-Nx SACs could effectively inhibit the reduction of ruthenium cation. To verify the DFT results, Ru-Nx SACs were fabricated by pyrolyzing MOFs in-situ spatially confined metal precursors. The N coordination environment could be controlled by changing the pyrolysis temperature. Catalytic performance tests indicated that low N coordination number (Ru–N2, Ru–N3) exhibited excellent catalytic activity and stability compared to RuCl3 catalyst. DFT calculations further revealed that Ru–N2 and Ru–N3 had a tendency to activate HCl at the first step of reaction, whereas Ru–N4 tended to activate C2H2. These findings will serve as a reference for the design and control of metal active sites. We have controllably constructed Ru-Nx SACs with different N coordination environment, which was conducive to the structure-performance relationship study and exhibited enhanced catalytic performance compared with traditional carbon-supported RuCl3 catalyst. This work provided a reference for the design and control of metal active sites. [Display omitted] •DFT calculations were used to simulate activity of M-Nx SACs (M = Hg, Cu, Au, Ru).•Ru-Nx SACs were fabricated via an in situ spatially confined Ru atoms using ZIF-8.•The N environment of Ru-Nx SACs could be regulated by changing pyrolysis temperature.•Ru–N2 and Ru–N3 SACs exhibited outstanding C2H2 conversion and stability.•Ru–N2 and Ru–N3 tended to activate HCl first whereas Ru–N4 tended to activate C2H2.