Flame Synthesis of Zr/ZSM-5 Catalysts with Tunable Acidity for the Oxidative Dehydrogenation of Propane to Propene  

作　　者：DANIEL Samuel FONZEU MONGUEN Cedric Karel WU Lingnan TIAN Zhenyu 

机构地区：[1]Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Thermal Science》2024年第1期268-283,共16页热科学学报（英文版）

基　　金：financial support from the National Natural Science Foundation of China (No. 52161145105/51888103/51976216);Ministry of Science and Technology of China (2017YFA0402800);Beijing Municipal Natural Science Foundation (JQ20017);K.C. Wong Education Foundation (GJTD-2020-07);Recruitment of Global Youth Experts;the financial support of the Belt and Road scholarship;the financial support of the ANSO scholarship;the support of the Chinese Academy of Sciences for the CAS project (Grant No.2018/43)。

摘　　要：Tuning the surface acidity of ZSM-5 catalyst is essential to achieve desired propene selectivity and yield.Here several ratios of Zr were utilized to modify ZSM-5 via flame spray pyrolysis technique coupled with a pulse spray evaporation system.The interaction between Zr and ZSM-5 in the flame influenced the physicochemical and acidity properties of the Zr/ZSM-5.The increasing Zr ratio in ZSM-5 shows coated layers of irregular nano-sized Zr with an increase in crystallite sizes due to the synergetic effect between Zr and ZSM-5.The surface chemical analysis revealed increased lattice oxygen on the Zr modified ZSM-5(1:4) sample compared to other catalysts.The acidity analysis revealed the Lewis and Br?nsted acid distribution in the weak and medium acid sites on the catalyst surface.However,the increase in Zr loading decreased the concentration of Br?nsted acid sites and tuned the catalyst surface to more Lewis acidity,promoting propene selectivity and hindering the over-oxidation of propene.The modified ZSM-5 catalysts were examined in a fixed bed reactor within 300℃-700℃ at a gas hourly space velocity(GHSV) of 6000 mL·g(catalysts)^(-1)·h^(-1) for the oxidative dehydrogenation of propane(ODHP) to propene.Among the catalysts,Zr/ZSM-5(1:4) exhibited the best propene yield, with 57.19% propane conversion and 75.54% selectivity to propene and the highest stability.This work provides a promising strategy for tuning the surface acidity of ZSM-5 with Zr for ODHP applications.

关 键 词：flame synthesis Zr modified ZSM-5 catalyst ODHP surface acidity lattice oxygen 

分 类 号：TQ221.212[化学工程—有机化工] TQ426