铜-铈/ZSM-5分子筛催化剂制备及脱硝性能研究

氮氧化物是大气主要污染源之一,危害人体健康,并引发酸雨。随着环保法规的升级,氮氧化物排放浓度的限值要求越来越高。这要求脱硝工艺尤其是脱硝催化剂必须进一步提高脱硝性能。以ZSM-5分子筛为载体,以铜、铈为活性组分,制备脱硝催化剂活性组分;用铝胶将脱硝催化剂活性组分附着在蜂窝状陶瓷上,得到脱硝催化剂。与ZSM-5分子筛相比,脱硝催化剂活性组分增加了4.73%的铜（以CuO质量分数计）和5.40%的铈（以CeO₂质量分数计）,比表面积由287.04 m²/g降到275.05 m²/g,孔容、孔径未发生变化,酸性增强,晶型基本保持不变。脱硝催化剂最佳反应条件：反应时间≥60 min,反应温度≥250 ℃,空速≤10 200 h^-1。脱硝催化剂在最佳反应条件下的脱硝效率约为85%。脱硝催化剂能适应较低的反应温度,并且具有较高的脱硝效率。

Study on preparation and denitration performance of Cu-Ce/ZSM-5 zeolite catalyst

Nitrogen oxide is one of the main air pollution sources,which is harmful to human health and causes acid rain. With the upgrading of environmental protection regulations,the limit of NO_x emission concentration is becoming lower and lower.It requires the denitration process,especially the denitration catalyst,to further improve the denitration performance. Using ZSM-5 molecular sieve as carrier,copper and cerium as active components,the active components of denitration cata-lyst were prepared.The active components of denitration catalyst were attached to honeycomb ceramics with aluminum glue to obtain denitration catalyst.Compared with ZSM-5 molecular sieve,the active component of denitration catalyst increased by 4.73% of Cu（calculated by the mass fraction of CuO） and 5.40% of Ce（calculated by the mass fraction of CeO₂）,and the spe-cific surface decreased from 287.04 m²/g to 275.05 m²/g,and the pore volume and the pore size remained unchanged,and the acidity increased,and the crystal form remained basically unchanged.The optimal reaction conditions of denitrification cata-lyst were that reaction time was more than or equal to 60 min,temperature was more than or equal to 250 ℃,and airspeed was less than or equal to 10 200 h^-1.The denitration efficiency of the catalyst was about 85% under the optimum reaction conditions.The catalyst could adapt to lower reaction temperature and had higher denitration efficiency.