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利用自行研制的全自动催化剂活性评价装置和原位漫反射红外光谱仪 ,分别考察了Ag的负载量和形态、氧浓度及水蒸气添加对Ag/Al2 O3 催化剂上C3 H6选择性催化还原NO性能的影响 .结果表明 ,Ag的最佳负载量为 4 %～ 6 % ,此时粒径为 15nm左右的银簇粒子均匀地分散在Al2 O3 载体表面 .在GHSV =5 0 0 0 0h-1和θ =4 30～ 5 5 0℃条件下 ,4 %Ag/Al2 O3 上NO转化率可达 90 %以上 .反应过程中有机含氮化合物及NO2 的生成 ,导致NO和NOx 转化率间产生差异 .当氧浓度为 7%时 ,催化剂对NO选择性还原的催化活性最高 .水的添加阻碍了活性中间物种NCO及其前驱体的形成 ,导致催化剂的平均活性下降
The catalytic activity of selective catalytic reduction of NO3 on Hg / Al2O3 catalyst was investigated by means of automatic catalyst activity evaluation device and in-situ diffuse reflectance infrared spectrometer. The effects of Ag loading, oxygen concentration and water vapor addition on the selective catalytic reduction of NO3 .The results show that the optimal loading of Ag is 4% ~ 6%, at this time the silver particles with particle size of about 15nm are uniformly dispersed on the surface of Al 2 O 3 carrier.When GHSV = 500h -1 and θ = 4 The conversion of NO over 4% Ag / Al 2 O 3 can reach more than 90% under the temperature of 30-550 ℃ .The formation of organic nitrogen compounds and NO 2 during the reaction leads to the difference of NO and NO x conversion rate When the oxygen concentration is 7%, the catalyst has the highest catalytic activity for the selective reduction of NO. The addition of water hinders the formation of the active intermediate species NCO and its precursor, resulting in a decrease in the average activity of the catalyst