Chinese Journal of Catalysis ›› 2019, Vol. 40 ›› Issue (6): 819-825.DOI: 10.1016/S1872-2067(18)63196-1

• Special Column on the 11th National Conference on Environmental Catalysis and Eco-Materia • Previous Articles     Next Articles

Electronic interaction between single Pt atom and vacancies on boron nitride nanosheets and its influence on the catalytic performance in the direct dehydrogenation of propane

Xiaoying Suna, Meijun Liua, Yaoyao Huanga, Bo Lic, Zhen Zhaoa,b   

  1. a Institute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang 110034, Liaoning, China;
    b State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China;
    c Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China
  • Received:2018-09-20 Revised:2018-11-07 Online:2019-06-18 Published:2019-04-26
  • Contact: 10.1016/S1872-2067(18)63196-1
  • Supported by:

    This work was supported by the National Science Foundation of China (91545117), the Natural Science Foundation of Liaoning Province (201602676), the Fundamental Research Funds for Colleges and Universities in Liaoning Province (LQN201703), and the Startup Foundation for Doctors of Shenyang Normal University (BS201620).

Abstract:

The electronic metal-support interaction (EMSI) is one of most intriguing phenomena in heterogeneous catalysis. In this work, this subtle effect is clearly demonstrated by density functional theory (DFT) calculations of single Pt atom supported on vacancies in a boron nitride nanosheet. Moreover, the relation between the EMSI and the performance of Pt in propane direct dehydrogenation (PDH) is investigated in detail. The charge state and partial density of states of single Pt atom show distinct features at different anchoring positions, such as boron and nitrogen vacancies (Bvac and Nvac, respectively). Single Pt atom become positively and negatively charged on Bvac and Nvac, respectively. Therefore, the electronic structure of Pt can be adjusted by rational deposition on the support. Moreover, Pt atoms in different charge states have been shown to have different catalytic abilities in PDH. The DFT calculations reveal that Pt atoms on Bvac (Pt-Bvac) have much higher reactivity towards reactant/product adsorption and C-H bond activation than Pt supported on Nvac (Pt-Nvac), with larger adsorption energy and lower barrier along the reaction pathway. However, the high reactivity of Pt-Bvac also hinders propene desorption, which could lead to unwanted deep dehydrogenation. Therefore, the results obtained herein suggest that a balanced reactivity for C-H activation in propane and propene desorption is required to achieve optimum yields. Based on this descriptor, a single Pt atom on a nitrogen vacancy is considered an effective catalyst for PDH. Furthermore, the deep dehydrogenation of the formed propene is significantly suppressed, owing to the large barrier on Pt-Nvac. The current work demonstrates that the catalytic properties of supported single Pt atoms can be tuned by rationally depositing them on a boron nitride nanosheet and highlights the great potential of single-atom catalysis in the PDH reaction.

Key words: Propane, Direct dehydrogenation, Platinum, Boron nitride, Single atom catalysis, Density functional theory, Electronic metel-support interaction