不同载体负载的Mn系复合氧化物催化剂性能研究  

Study on Performance of Mn-Based Oxide Catalysts on Different Supports

作　　者：王学涛[1] 张小龙[1] 焦叶凡[1] 张兴宇[1] 

机构地区：[1]河南科技大学能源与动力工程系,河南洛阳471003

出　　处：《锅炉技术》2015年第4期7-11,80,共6页Boiler Technology

基　　金：国家自然科学基金项目(50806020);河南省科技创新人才计划(杰出青年)(114100510010)

摘　　要：采用溶胶凝胶法和浸渍法将Mn的氧化物分别负载到TiO2、γ-Al2O32种载体上,通过BET、XRD、H2-TPR和NH3-TPD等表征方法考察了MnOx/γ-Al2O3和MnOx/TiO2催化剂的物化特性,同时在反应器上进行的脱硝活性测试。BET、XRD、SEM测试结果表明：MnOx/γ-Al2O3的孔结构与比表面积优于MnOx/TiO2,而MnOx在TiO2上的结晶度较差,分散性较好,其催化剂疏松结构更有利于反应气体与活性物质充分接触。TPR和TPD结果表明：MnOx/TiO2在低温下有较好的氧化还原能力,但是催化剂表面酸性强度弱于MnOx/γ-Al2O3。脱硝性能测试结果表明：TiO2和γ-Al2O3作为载体的MnOx催化剂均表现出较好的SCR活性,其中当MnOx/TiO2催化剂在低温范围内（80℃~200℃）脱硝效率上升较快,在140℃时,NO转化率已经达到60%以上,在200℃左右,NO转化率达到90%左右,之后随反应温度升高脱硝效率没有明显变化;MnOx/γ-Al2O3在260℃以下,催化剂的活性较差,在380℃时,其NO转化率达到85%。因此,低温条件下TiO2更适合作为MnOx催化剂的载体。Manganese oxide was supported on the TiO2 and γ-Al2O32 by sol-gel and impregnation method. The physicochemical characteristics of MnOx/γ-Al2O32 and MnOx/TiO2 were investigated by BET, XRD, H2-TPR and NH3-TPD. The results of BET, XRD, and SEM show that the pore structure and specific surface area of MnOx/γ-Al2O32 is better than MnOx/TiO2, and MnOx crystallinity on TiO2 is poorer, dispersivity is good, the catalyst loose structure is more favorable for full contact reaction gas and the active material. TPR and TPD results indicated that MnOx/TiO2 has good redox ability at low temperature, but surface acidity is weaker than MnOx/γ-Al2O32. Denitrification activity test indicated that MnOx-based catalysts and TiO2 and γ-Al2O32 used as carrier has Higher SCR activity, which denitration efficiency rise faster in the range of low temperature （80 ℃ -200 ℃）, NOx conversion reached upon 60% at 140℃, and NO conversion reached around 90% at 200 ℃, then denitration efficiency will remain stable with increasing of reaction temperature; The MnOx/ γ-Al2O32 activity were lower under 260 ℃, and NO conversion reached 85%. Therefore, TiO2 is brtter than MnOx as catalyst carrier under low temperature conditions.

关 键 词：催化剂 载体 MNOX 脱硝 

分 类 号：X701.3[环境科学与工程—环境工程]