溶胶-凝胶法制备颗粒状催化剂低温SCR脱硝性能

Characteristics of low-temperature selective catalytic reduction deNO_x catalyst powder by sol-gel method

采用溶胶凝胶法制备了Mn-Ce/TiO2催化剂,并将其用于低温NH3选择催化还原NO的反应（NH3-SCR）,考察了反应温度、空速、氧气浓度、氮氧化物浓度和氨氮比等反应条件对催化剂性能的影响.结果表明,NO入口浓度为800 ～1 600 mg/m3时,催化剂活性受NO初始浓度的影响较小.反应温度和氨氮比对NO转化率影响显著,100 ～ 150℃温度范围内,NO转化率随温度升高快速上升;当[NH3]/[NO]＜1.1时,随着[NH3]/[NO]的增加,NO转化率很快上升.反应体系中适当的O2浓度可促进NO还原为N2.空速大于10 000 h-1时,NO转化率随着空速的增大而降低.

A manganese and cerium oxide catalyst was prepared by the sol-gel method and used for the low- temperature selective catalytic reduction （SCR） of NO with NH3. The influences of reaction temperature, space velocity, concentration of O2 and nitrogen oxide, and ammonia nitrogen ratio on the conversion of NO over Mn- Ce/TiO2 were investigated. The results showed that the change of the concentration of NO did not affect the con- version of NO when the concentration ranged from 800 mg/m3 to 1 600 mg/m3. Reaction temperature and ammo- nia nitrogen ratio had significant effect on the conversion of NO. When the reaction temperature was 100 ～ 150℃, the conversion of NO increased along with the reaction temperature. When the ammonia nitrogen ratio was smaller than 1. 1, the conversion of NO increased along with the ammonia nitrogen ratio. Proper concentra- tion of O2 promoted the reduction of NO to N2. When space velocity was greater than 10 000 h^-1, NO conversion decreased with increasing space velocity.