铁基催化剂的微波水热处理对其SCR脱硝性能的影响

利用微波对共沉淀制备的铁铈钛复合氧化物催化剂前驱体进行水热处理,探讨了微波水热处理对铁基催化剂低温SCR脱硝性能的优化;并对微波水热处理条件的影响进行了正交分析.结果表明:对铁基催化剂前驱体进行微波水热处理,可提高其低温SCR脱硝性能,使其脱硝温度窗口向低温偏移;且微波水热处理的低温优化效果与催化剂中Fe/Ti摩尔比密切相关,Fe/Ti摩尔比越小,微波水热处理的低温优化越强;微波加热方式和微波辐射时间会影响微波水热处理对铁基催化剂SCR脱硝性能的低温优化;在相同微波辐射时间条件下,当P30逐渐变为P80,微波水热处理对铁基催化剂低温SCR脱硝的促进作用降低;在P30条件下,微波辐射15min使铁基催化剂具有最佳低温SCR脱硝活性.

Effect of microwave hydrothermal treatment for iron-based catalyst on its selective catalytic reduction of NO with NH3

Microwave was used to hydrothermally treat the precursors of iron-cerium-titanium mixed oxide catalysts prepared by co-precipitation.The optimization of microwave hydrothermal treatment on the low-temperature NH3-SCR activity over iron-based catalyst were investigated in a fixed-bed quartz tube reactor,and the influences of microwave hydrothermal treatment conditions were also studied through the orthogonal experiment.The results indicated that microwave hydrothermal treatment could improved the low-temperature NH3-SCR activity of iron-based catalyst,and made its reactive SCR temperature window shift to the low-temperature region.Meanwhile,the promotional effect of microwave hydrothermal treatment on low-temperature NH3-SCR activity is closely related to the molar ratio of Fe and Ti in the mixed oxide catalyst.When the molar ratio of Fe and Ti is smaller,the promotion of microwave hydrothermal treatment is higher.The microwave heating method and the microwave radiation time played an important role on the promotion of low-temperature NH3-SCR activity over iron-based catalyst.Under the same microwave radiation time,when the microwave heating method was changed from P30to P80,the promotion of microwave hydrothermal treatment on low-temperature NH3-SCR activity over iron-based catalyst gradually decreased.Under the condition of P30,iron-based catalyst showed the highest NH3-SCR activity after being treated by microwave radiation for 15min.