砷中毒商业V_2O_5-WO_3/TiO_2催化剂的再生方法

Regeneration Method of Arsenic Poisoned Commercial SCR Catalyst

基于商业V_2O_5-WO_3/TiO_2脱硝催化剂,通过将催化剂浸渍在砷标准溶液中,制备了砷中毒催化剂。用不同浓度FeCl_3溶液清洗,通过活性测试并结合X射线衍射(XRD)、比表面积测定(BET)、原位漫反射傅里叶变换红外光谱(in situ DRIFTS)的表征技术对As中毒催化剂再生前后的微观结构、表面酸性变化、脱硝活性进行了对比研究,探索FeCl_3对砷中毒催化剂的再生效果与机理。结果表明,20 mg/mL的FeCl_3溶液对催化剂的再生效果较好,恢复了催化剂被砷堵塞的小孔,增加了比表面积和孔体积,降低了平均孔径,同时增强了催化剂表面的Bronsted酸和Lewis酸酸位的强度和酸量,延长了催化剂的吸附饱和时间,350-400℃时催化剂的脱硝活性恢复到80.07%以上。

Based on commercial V2O5-WO3/TiO2 catalyst, Arsenic poisoned catalyst was sinmlated by impregnating the catalyst in arsenic standard solution, then the catalysts were regenerated by cleaning the catalyst with FeCl3 solution, the changes of physico-chemical properties between poisoned and regenerated catalyst were investigated by characteristics techniques, like BET specific surface area measurement, X-ray diffraction（XRD）, In-situ diffuse reflectance infrared spectrometry [in situ DRIFTS）, and the catalytic performance for SCR catalysts were explored comparatively. The results showed that 20 mg/mL FeCl3 solution for catalyst regeneration effect is best, small pores which blocked by arsenic was cleaned, the specific surface area and pore volume were increased, the average pore diameter was reduced, meanwhile, FeCl3 solution enhanced the intensity of both BrФnsted acid Sites and Lewis acid sites and increased the amount of acid, prolonged the time of the catalyst adsorption saturation, increased the denitration catalyst activity to more than 80.07%.