SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 57 ›› Issue (5): 39-49.DOI: 10.1016/j.cjche.2022.08.014

• Full Length Article • 上一篇    下一篇

Mechanistic insights into propylene oxidation to acrolein over gold catalysts

Bin Lin, Wenyao Chen, Nan Song, Zhihua Zhang, Qianhong Wang, Wei Du, Xinggui Zhou, Xuezhi Duan   

  1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • 收稿日期:2022-04-13 修回日期:2022-08-02 出版日期:2023-05-28 发布日期:2023-07-08
  • 通讯作者: Nan Song,E-mail:cuiky@ecust.edu.cn;Xuezhi Duan,E-mail:xzduan@ecust.edu.cn
  • 基金资助:
    This work was financially supported by the Research Fund for National Key Research and Development Program of China (2021YFA1501403), the National Natural Science Foundation of China (22208094, 22038003, 21922803, 22178100), the Innovation Program of Shanghai Municipal Education Commission, the Program of Shanghai Academic/Technology Research Leader (21XD1421000) and the Shanghai Science and Technology Innovation Action Plan (22JC1403800).

Mechanistic insights into propylene oxidation to acrolein over gold catalysts

Bin Lin, Wenyao Chen, Nan Song, Zhihua Zhang, Qianhong Wang, Wei Du, Xinggui Zhou, Xuezhi Duan   

  1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2022-04-13 Revised:2022-08-02 Online:2023-05-28 Published:2023-07-08
  • Contact: Nan Song,E-mail:cuiky@ecust.edu.cn;Xuezhi Duan,E-mail:xzduan@ecust.edu.cn
  • Supported by:
    This work was financially supported by the Research Fund for National Key Research and Development Program of China (2021YFA1501403), the National Natural Science Foundation of China (22208094, 22038003, 21922803, 22178100), the Innovation Program of Shanghai Municipal Education Commission, the Program of Shanghai Academic/Technology Research Leader (21XD1421000) and the Shanghai Science and Technology Innovation Action Plan (22JC1403800).

摘要: Direct epoxidation of propylene with H2/O2, being the dream reaction for propylene oxide (PO) production, has raised wide scientific and industrial interests. Fundamentally understanding the formation mechanism of acrolein, as the main by-product of this epoxidation process, is very important to achieve the high yield of PO. In this study, we perform the spin-polarized density functional theory (DFT) calculations to investigate the reaction pathway from propylene to acrolein over two representative Au surfaces, that is, Au(1 1 1) and Au(1 0 0), which incorporates propylene adsorption, methyl hydrogen activation and acrolein formation. The results show that the oxygenated species (mainly O*, OH* and OOH*) are able to stabilize the adsorption of propylene to decrease the energy barrier for its activation. It is demonstrated that the OOH* on Au(1 1 1) surface emerges as the most easily formed oxygenated species via the H-assisted O2 dissociation, which is also the most active for the cleavage of methyl C-H bond in propylene. Furthermore, three pathways of acrolein formation activated by O*/OH*/OOH* are analyzed, in which O* is found as the key species to form acrolein. Finally, Bader charge analysis was conducted to explore the reasons behind the promotion effect of the oxygenated species. The insights reported here could be valuable in the design and optimization of gold catalysts for the direct epoxidation of propylene.

关键词: Acrolein formation, Oxygenated species, DFT calculations, Au surfaces, Reaction mechanism

Abstract: Direct epoxidation of propylene with H2/O2, being the dream reaction for propylene oxide (PO) production, has raised wide scientific and industrial interests. Fundamentally understanding the formation mechanism of acrolein, as the main by-product of this epoxidation process, is very important to achieve the high yield of PO. In this study, we perform the spin-polarized density functional theory (DFT) calculations to investigate the reaction pathway from propylene to acrolein over two representative Au surfaces, that is, Au(1 1 1) and Au(1 0 0), which incorporates propylene adsorption, methyl hydrogen activation and acrolein formation. The results show that the oxygenated species (mainly O*, OH* and OOH*) are able to stabilize the adsorption of propylene to decrease the energy barrier for its activation. It is demonstrated that the OOH* on Au(1 1 1) surface emerges as the most easily formed oxygenated species via the H-assisted O2 dissociation, which is also the most active for the cleavage of methyl C-H bond in propylene. Furthermore, three pathways of acrolein formation activated by O*/OH*/OOH* are analyzed, in which O* is found as the key species to form acrolein. Finally, Bader charge analysis was conducted to explore the reasons behind the promotion effect of the oxygenated species. The insights reported here could be valuable in the design and optimization of gold catalysts for the direct epoxidation of propylene.

Key words: Acrolein formation, Oxygenated species, DFT calculations, Au surfaces, Reaction mechanism