Investigating the CrOx/Al2O3 dehydrogenation catalyst model: II. Relative activity of the chromium species on the catalyst surface
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- 作者：Vladimir Z. Fridman ; Vladimir.Fridman@clariant.com ; Rong Xing
- 关键词：Dehydrogenation ; CrOx/Al2O3 catalyst ; Relative activity ; Chromium species ; Equilibrated
- 刊名：Applied Catalysis A: General
- 出版年：2017
- 出版时间：25 January 2017
- 年：2017
- 卷：530
- 期：Complete
- 页码：154-165
- 全文大小：2419 K
- 卷排序：530
文摘
The relative activity of five surface Cr species was evaluated by selecting model catalysts. The redox aluminum-chromium-chromate(s) were found active in the formation of C1–C3 hydrocracking byproducts and coke. Initial operation of the fresh CrOx/Al2O3 catalyst at the dehydrogenation-regeneration mode caused non redox Cr3+ on α-Cr2O3 originally inactive on the fresh catalyst to be very active in the equilibrated one, likely due to the surface restructuring of unstable chromium species. A reaction chemistry pathway for the thermal conversion of mono-/poly-aluminum chromate(s) and physically deposited CrO3 into the aluminum-chromium-chromate(s) was proposed.