γ-Al_2O_3负载多金属复合催化剂选择性催化还原烟气脱硝

γ-Al_2O_3 Supported Multi-Metal Composite Catalyst for SCR Denitrification of Flue Gas

以γ-Al_2O_3作为载体,先后负载CeO_2,MnC_2O_4,Fe(NO_3)_3,CrO_3,Ni(NO_3)_2,NH_4VO_3等多种金属组分制备γ-Al_2O_3负载多金属复合催化剂,并用于模拟烟气的选择性催化还原脱硝。通过SEM和XRD技术对催化剂进行了表征。表征结果显示:Fe,Mn,Cr的添加能增加催化剂的低温催化活性、提高催化剂的N2选择性;γ-Al_2O_3对活性金属氧化物的负载效果良好。实验结果表明:各金属化合物的最佳加入量为w(MnC_2O_4·2H_2O)=2 0%,w(Fe(NO_3)_3·9H_2O)=1 5%,w(CrO_3)=10%,w(Ni(NO_3)_2·6H_2O)=5%,w(NH_4VO_3)=10%,w(CeO_2)=5%,w(γ-Al_2O_3)=35%;以在最佳正交实验条件下制得的γ-Al_2O_3负载多金属复合物为催化剂,在脱硝反应温度为205℃的条件下,NO转化率为96.7%;γ-Al_2O_3负载多金属复合催化剂经5次重复使用,NO转化率仍可稳定在94%左右。

The γ-Al2O3 supported multi-metal composite catalyst was prepared by loading CeO2,MnC2O4,Fe（NO3）3,CrO3,Ni（NO3）2 and NH4VO3 on γ-Al2O3,and was used for SCR denitrification of the simulated flue gas. The catalyst was characterized by SEM and XRD. The characterization results show that：The low-temperature catalytic activity and N2 selectivity of the catalyst can be improved with the addition of Fe,Mn and Cr;γ-Al2O3 supports the active metal oxides well. The optimum dosages of metal compound are as follows：w（MnC2O4·2H2O）=20%,w（Fe（NO3）3·9H2O）=15%,w（CrO3）=10%,w（Ni（NO3）2·6H2O）=5%,w（NH4VO3）=10%,w（CeO2）=5%,w（γ-Al2O3）=35%. When the γ-Al2O3 supported multi-metal complex prepared under the optimum conditions is used as catalyst and the reaction temperature for denitrification is 205 ℃,the NO conversion rate is 96.7%. After theγ-Al2O3 supported multi-metal composite catalyst has used for 5 times,the NO conversion rate can still remain about 94%.