Generation of NH3 Selective Catalytic Reduction Active Catalysts from Decomposition of Supported FeVO4

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• 作者：Adrian Marberger ; Martin Elsener ; Davide Ferri ; Amod Sagar ; Karl Schermanz ; Oliver Kr枚cher
• 刊名：ACS Catalysis
• 出版年：2015
• 出版时间：July 2, 2015
• 年：2015
• 卷：5
• 期：7
• 页码：4180-4188
• 全文大小：484K
• ISSN：2155-5435

文摘

The effect of catalyst loading, composition, and calcination temperature on NH₃ selective catalytic reduction (SCR) activity was investigated for metal vanadates of the type Fe_xAl_1鈥搙VO₄ (0 鈮?x 鈮?1, MeVO₄) supported on TiO₂鈥揥O₃鈥揝iO₂ (TWS). The optimized catalyst (4.5 wt % FeVO₄/TWS calcined at 650 掳C) showed an enhanced NO_x reduction activity compared to the reference material 2.3 wt % V₂O₅/TWS. An activation effect was observed above a calcination at 600 掳C and was investigated by means of X-ray diffraction, Brunauer鈥揈mmett鈥揟eller, diffuse reflectance infrared Fourier transform, and X-ray absorption near edge structure analyses. It was shown that the activation is due to the decomposition of FeVO₄. VO_x species disperse and migrate to the support material, while the iron species sinter to Fe₂O₃ particles. We provide strong evidence that the active species responsible for NH₃鈥揝CR in a FeVO₄/TWS catalyst is not FeVO₄ but VO_x species that possess a similar coordination environment to the VO_x species on conventional V-based catalysts. Due to the remarkable effect of the activation upon calcination, a very active and thermally stable SCR catalyst up to 700 掳C was obtained.