SAPO-34提升铁钒基催化剂抗碱性能研究

采用浸渍法制备Fe-VO_x/SAPO-34和Fe-VO_x/TiO₂脱硝催化剂,探究SAPO-34分子筛与TiO₂两种载体负载铁钒基氧化物催化活性及抗碱性能的差异。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、氨气程序升温脱附(NH₃-TPD)、氢气程序升温还原(H₂-TPR)、原位红外漫反射(in-situ DRIFTs)等表征手段对催化剂的骨架结构、表面物化性质、氧化还原能力以及对反应气体的吸脱附情况进行分析。结果表明:SAPO-34分子筛内部特定的孔道结构和稳定的骨架,有利于活性组分在载体上均匀分散,降低碱金属对表面活性中心的物理覆盖作用;同时其表面丰富的酸位点能够作为碱金属捕获位,保护催化剂表面的活性中心,保证催化剂的吸附-反应过程能够正常进行,从而使Fe-VO_x/SAPO-34表现出良好的抗碱金属能力。

Alkali Resistance of Iron Vanadium Based Oxides by SAPO-34

Fe-VO_x/SAPO-34 and Fe-VO_x/TiO₂ catalysts were prepared by impregnation method to explore the catalytic activity and alkali metal resistance of SAPO-34 molecular sieve and TiO₂ supported iron vanadium-based oxides. The catalysts were characterized by means of XRD, XPS, NH₃-TPD, H₂-TPR and in-situ DRIFTs. The results show that: the specific pore structure and stable skeleton in SAPO-34 molecular sieve are conducive to the uniform dispersion of active components on the carrier and reduce the physical coverage of alkali metals on the surface active centers; at the same time, the rich acid sites can be used as alkali metal capture sites to protect the active center on the catalyst surface and ensure the normal adsorption reaction process of the catalyst, so that Fe-VO_x/SAPO-34 shows good alkali metal resistance.