The effect of the Ce content on the oxidative dehydrogenation of propane over CrOy-CeO2/γ-Al2O3 catalysts

• 作者: Cheng Zuo Man Wu Qingjie Guo
• 来源期刊: 中国化学工程学报（英文版）
• 年，卷（期）: 2020,（12）
• 所属期刊栏目: Catalysis, Kinetics and Reaction Engineering
• 页码范围: 3035-3043
• 页数: 9页
• 语种: 英文

摘要

A series of CrOy (17.5 wt％)-CeO2 (X wt％)/γ-Al2O3 catalysts (X=0, 0.5, 2, 5, 8) with various Ce contents were pre-pared by a wetness impregnation method and were applied to the dehydrogenation of propane to propylene at 550 ℃ and 0.1 MPa. The prepared catalysts were characterized by BET, H2-TPR, O2-TPD, XPS, XRD, SEM-EDS and Raman spectroscopy. Among the prepared catalysts, the 17.5Cr-2Ce/Al catalyst with the largest amount of lattice oxygen exhibited the best catalytic performance for the dehydrogenation of propane to propylene with lattice oxygen. The decreased presence of oxygen defects and reducibility were the factors responsible for the improved dehydrogenation activity of the catalysts. The CeO2 layer could inhibit the evolution of lattice oxygen (O2-) to electrophilic oxygen species (O2-), and the oxygen defects on the catalyst surface were reduced. The inhibited lat-tice oxygen evolution prevented the deep oxidation of propane or propylene, the average COx selectivity de-creased from 24.41％(17.5Cr/Al) to 5.71％(17.5Cr-2Ce/Al), and the average propylene selectivity increased from 60.15％(17.5Cr/Al) to 85.05％(17.5Cr-2Ce/Al).