采用溶胶-凝胶法和浸渍法制备选择性催化还原(SCR)脱硝反应复合纳米催化剂Ce-V/TiO_2,在不同的实验条件下制备出一系列的TiO_2凝胶用作催化剂载体.然后通过浸渍法依次负载CeO_2和V_2O_5于多孔TiO_2载体.用氨气作为还原性气体,对选择性催化还原NOx进行实验研究.在不同的TiO_2载体煅烧温度、CeO_2和V_2O_5负载量以及催化还原反应温度等条件下,对催化剂的表面结构和催化性能采用BET、XRD、SEM等手段进行表征分析.结果表明,纳米Ce-V/TiO_2固溶体复合催化剂以及对其制备工艺技术参数的优化可增大催化剂的比表面积和微孔体积,使催化剂的催化活性有很大的提高.此外,相当数量的多孔纳米TiO_2大大增加了光催化活性的有效面积,有利于增大与反应物的接触面积和提高光催化活性.当载体TiO_2 的煅烧温度和催化还原反应温度为500 ℃时,5%Ce-10%V/TiO_2催化剂反应的NO_x转化率可达96.2%.
The nano-Ce-V/TiO_2 catalysts with the selective catalytic reduction (SCR) were prepared by sol-gel and insuccation method. The phase compositions, microstructures and specific surface area of the catalysts were analyzed by XRD, SEM and BET, respectively. The effects of nano-TiO_2 Calcination temperature, CeO_2 and V_2O_5 loading and reaction temperature on the catalytic performances of the as-prepared catalysts were investigated by the selective reduction of NO_x with NH_3. The results showed all the as-prepared Ce-V/TiO_2 catalysts were made up of nanometer grains. Compared with conventional TiO_2 catalysts, the as-prepared Ce-V/TiO_2 catalysts possessed better catalytic performance, higher adsorbability and larger area of contact with reactant, which was due to large quantity surface micropores. The NO_x conversion of SCR over 5wt%Ce-10wt%V/TiO_2 catalysts reached 96.2% at the reaction temperature of 500 ℃.
参考文献
| [1] | Xiufeng Ren et al.[J].Chinese Industrial Catalysis,2008,16(02):49. |
| [2] | Hiroshi Akama.[J].Catalysis Surveys from Japan,1999(03):139. |
| [3] | Janssen F J;Ertl G.Handbook of Heterogeneous Catalysis[M].Weinheim:Wiley-VCH,1997:1633. |
| [4] | Centi G.Selective Oxidation by Heterogeneous Catalysis[M].New York:Kluwer Academic-Plenum Publishers,2001 |
| [5] | Armor J N .[J].Catalysis Today,1995,26:147. |
| [6] | Fokema M D et al.[J].Catalysis Review:Science and Engineering,2001,43:1. |
| [7] | Haber J;Ertl G;Kn?zinger H;Weitkamp J.Handbook of Heterogeneous Catalysis[M].Weinheim:Wiley-VCH,1997:2253. |
| [8] | Went Gregory Thomas .Study of Supported Vanadium Oxide Catalysts for Selective Catalytic Reduction of Nitrogen Oxides[D].Berkeley:University of Califonia,1991. |
| [9] | Okazaki S et al.[J].Industrial and Engineering Chemistry:Product Research and Development,1991,20:301. |
| [10] | 雷波,徐悦华,郭来秋,罗海燕.Ce-TiO2/硅藻土的制备、表征及其光催化活性[J].中国有色金属学报,2007(05):795-799. |
| [11] | Liu Zhiming et al.[J].Catalysis Letters,2006,106:35. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%