Efficient epoxidation of propylene over non-noble nickel-based catalyst promoted by alkali metals  

作　　者：Wenqian Li Wanting Li Xinxin Cao Longfei Chen Yibo Qin Yanfeng Zhu Yanfei Zhang Gai Miao Lingzhao Kong Jiong Li Xinqing Chen 

机构地区：[1]State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization,CAS Key Laboratory of Low-carbon Conversion Science and Engineering,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]School of Environmental Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China [4]Shanghai Synchrotron Radiation Facility,Zhangjiang National Lab,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China

出　　处：《Science China Chemistry》2024年第11期3697-3705,共9页中国科学（化学英文版）

基　　金：supported by the National Key Research and Development Program of China (2022YFE0208300);the National Natural Science Foundation of China (22078354, 22108290)。

摘　　要：The application of non-noble metal catalysts in the catalytic direct gas-phase epoxidation of propylene with H2and O2to produce propylene oxide is valuable and challenging. The introduction of alkali metal promoters is one of the effective methods to improve the catalytic activity of catalysts. Herein, a series of alkali metal(Li, Na, K, Rb, and Cs)-promoted Ni/TS-1 catalysts were prepared to deeply understand the effect of alkali metals on the structure-activity relationship for gas-phase epoxidation of propylene. Among them, the Na-Ni/TS-1 catalyst exhibits the highest catalytic activity(propylene conversion of 7.35% and PO formation rate of 157.9 g h^(-1)kg_(cat)^(-1)) and the best stability(long-term stability exceeding 140 h at 200 ℃). X-ray absorption and photoelectron spectroscopy revealed that the electronic structure of Ni can be tuned by the addition of alkali metal promoters.NH3-TPD-MS, CO_(2)-TPD-MS, and C_(3)H_(6)-TPD-MS results indicate that the acidity of the catalyst can also be adjusted by the introduction of alkali metal, whereas the Na-Ni/TS-1 catalyst exhibits the strongest C_(3)H_(6) adsorption capacity. Thus, the suitable acid-base properties, unique electronic properties of Ni species, and the strongest propylene adsorption capacity resulted in improved propylene gas-phase epoxidation activity of Na-Ni/TS-1 catalyst. This study not only provides a new strategy for the practical application of nickel-based catalysts in the gas-phase epoxidation of propylene but also provides insights into the promoting effect of alkali metals.

关 键 词：PROPYLENE EPOXIDATION Ni/TS-1 catalyst alkali metal precipitating agents 

分 类 号：O643.36[理学—物理化学]