关键词: 沉淀剂;共沉淀法;Mn-Ce/TiO2;脱硝性能

Abstract: Mn-Ce/TiO2 catalysts were prepared by coprecipitation method using NH4OH,(NH4)2CO3 and NaOH as precipitants,and the catalysts were characterized by XRD,BET,NH3-TPD and XPS.The effect of precipitant on SCR denitrification of Mn-Ce/TiO2 catalyst was discussed.The results show that Mn-Ce/TiO2 catalyst prepared with NH4OH as precipitant exhibits the best low temperature denitrification activity compared with (NH4)2 CO3 and NaOH.When the space velocity is 16000 h-1 and the loading of the active component is 15;,the NO removal rate of the catalyst is above 85; at 80 ℃.This is mainly due to the fact that the manganese oxide in the catalyst is mainly in the amorphous state;its pore structure is more refined,the pore size is smaller and the larger pore volume provides favorable conditions for the uniform loading of the active component;The catalyst has more weak acid sites and moderate acid sites,and has good redox resistance,which is favorable for the adsorption and oxidation of NO and NH3,which effectively promotes the low temperature SCR denitrification activity of the catalyst.

Key words: Mn-Ce/TiO2 catalysts were prepared by coprecipitation method using NH4OH,(NH4)2CO3 and NaOH as precipitants,and the catalysts were characterized by XRD,BET,NH3-TPD and XPS.The effect of precipitant on SCR denitrification of Mn-Ce/TiO2 catalyst was discussed.The results show that Mn-Ce/TiO2 catalyst prepared with NH4OH as precipitant exhibits the best low temperature denitrification activity compared with (NH4)2 CO3 and NaOH.When the space velocity is 16000 h-1 and the loading of the active component is 15;,the NO removal rate of the catalyst is above 85; at 80 ℃.This is mainly due to the fact that the manganese oxide in the catalyst is mainly in the amorphous state;its pore structure is more refined,the pore size is smaller and the larger pore volume provides favorable conditions for the uniform loading of the active component;The catalyst has more weak acid sites and moderate acid sites,and has good redox resistance,which is favorable for the adsorption and oxidation of NO and NH3,which effectively promotes the low temperature SCR denitrification activity of the catalyst.