以改性TiO_2-SnO_2为载体的SCR脱硝催化剂性能

Catalytic performance of the SCR catalyst supported on modified TiO_2-SnO_2 carrier

研究以共沉淀法制备TiO_2-SnO_2复合载体,浸渍负载活性组分CeO_2制成SCR脱硝催化剂。以NH3为还原剂,在适当的模拟烟气的实验条件下,考察了不同载体催化剂在150~400℃内对脱硝性能的影响。实验结果表明,经过改性的TiO_2-SnO_2复合载体改性对催化剂的脱硝性能有较大的影响,SnO_2的加入大大提高了Ce/TiO_2的脱硝效率,并可以在一定程度上抵抗SO2带来的毒害和钝化作用。此外,利用BET、XRD和SEM等表征手段,研究载体改性对催化剂微观结构的影响。表征结果显示,SnO_2的掺杂可在一定程度上促进载体及催化剂比表面积的增加,复合载体TiO_2-SnO_2对于活性组分CeO_2有着更好的分散性,活性组分CeO_2以高度分散的形式存在或呈无定型状态存在于复合载体TiO_2-SnO_2的表面,未出现团聚的现象。

Selective catalytic reduction（ SCR） catalysts were synthesized using the co-incipient method and modified binary-oxide supported TiO_2-SnO_2 was loaded with CeO_2（ active component）. The support effect on the NO removal efficiency was investigated using a propitiate,simulated flue gas and NH_3 as a reducing agent,between 150 ～ 400 ℃. This result indicated that the modified binary-oxide supported TiO_2-SnO_2 had a marked influence on the NO removal efficiency; introduction of SnO_2 can significantly improve the NO removal efficiency of Ce / TiO_2 and enhance the resistance of Ce / TiO_2 to SO_2. A series of microstructure characterizations（ BET,XRD,and SEM） revealed that the introduction of SnO_2 greatly increased the BET specific surface. Moreover,the active component（ CeO_2） was shown to have improved dispersibility on the modified binary-oxide supported TiO_2-SnO_2,and possibly existed as an amorphous phase.