锰前驱体对负载型氧化锰催化剂脱硝性能的影响

分别以醋酸锰、醋酸锰-硫酸锰以及硫酸锰为前驱体，采用浸渍法制备Mn/Al₂O₃催化剂，考察其SCR脱硝活性和耐硫性能。采用BET、XRD、FT-IR、H₂-TPR和NH₃-TPD等对催化剂进行表征。结果表明，锰前驱体不同，导致催化剂晶型、比表面积存在显著差异；硫酸锰的加入使催化剂表面总酸量和酸强度上升。与单独的醋酸锰和硫酸锰相比，醋酸锰-硫酸锰复合前驱体制备的催化剂可以提高催化剂在（300~450） ℃的NO转化率，且原料气中SO₂体积分数为0.2%时，脱硝率下降幅度最小，耐硫性能最好。因此，采用醋酸锰-硫酸锰复合前驱体制备催化剂，可以提高催化剂在高温区的脱硝活性和抗硫性能。

Effects of Mn precursors on performance of supported Mn/Al2 O3 catalysts for selective catalytic reduction of NO

Using manganese acetate,manganese sulfate and the mixture of manganese acetate-manganese sulfate as Mn precursors,respectively,Mn / Al2O3 catalysts were prepared by the impregnation method. The as-prepared Mn / Al2O3 catalysts were characterized by BET,XRD,FT-IR,H2-TPR and NH3-TPD. The de-NOx activity and sulfur tolerance properties of Mn / Al2O3 catalysts were investigated. The results indicated that the crystal and the specific surface area of the catalysts were apparently different due to different Mn precursors. The total acid amount and acid strength of the catalyst surface were enhanced with the addition of manganese sulfate. Compared with the catalysts prepared with manganese acetate and manganese sulfate,the catalysts prepared with mixture of manganese acetate and manganese sulfate could improve the conversion of NO at（ 300-450） ℃,and when SO2 volume fraction in the feed stream was0. 2%,the activities of the catalyst for De-NOx declined slightly,and its sulfur tolerance properties was the best. Therefore,the catalysts prepared with composite precursor could improve the catalytic activity and the sulfur resistance of the catalyst at high temperature.