分别采用浸渍法和机械混合法制备了Cr改性的In/WO_3/zrO_2(In/WZr)催化剂,考察了改性前后催化剂的CH4选择性催化还原NO的活性.结果表明,将Cr_2O_3与In/WZr机械混合可显著提高In/WZr催化剂活性,Cr的加入促进了气相中NO向NO_2的转化.而浸渍法制备的Cr/InAVZr催化剂活性远低于改性前的In/WZr催化剂,这是由于在制备过程中部分Cr_2O_3转化为CrO_3,使其氧化性大大提高,从而将CH_4完全氧化为CO_2和H_2O,不利于将CH_4活化为反应所需的中间活性物种.
Cr-modified In/WO_3/ZrO_2 (In/WZr) catalysts were prepared by impregnation and mechanical mixing methods. Their activity for selective catalytic reduction of NO with CH4 was investigated. The results showed that the catalyst activity was enhanced by mixing Cr_2O_3 with In/WZr. The enhancement of the activity was due to the oxidation ability of Cr_2O_3, which improved the conversion of NO to NO_2. However, for the catalysts prepared by impregnation, some of the trivalent chromium (Cr~(3+)) was converted to Cr(6+), which resulted in the lower activity than the initial In/WZr catalyst by the complete oxidation of CH_4 to CO_2 and H_2O.
参考文献
| [1] | Li Y J;Armor J N .[J].Applied Catalysis B:Environmental,1992,1:L31. |
| [2] | Kantcheva, M;Cayirtepe, I .FT-IR spectroscopic investigation of the surface reaction of CH4 with NOx species adsorbed on Pd/WO3-ZrO2 catalyst[J].Catalysis Letters,2007(3/4):148-162. |
| [3] | Kubacka A;Janas J;Sulikowski B .[J].Applied Catalysis B:Environmental,2006,69:43. |
| [4] | Maunula T;Ahola J;Hamada H .Reaction mechanism and microkinetic model for the binary catalyst combination of In/ZSM-5 and Pt/Al2O3 for NOx reduction by methane under lean conditions[J].Industrial & Engineering Chemistry Research,2007(9):2715-2725. |
| [5] | Yang D;Li J H;Wen M F;Song C L .[J].Catalysis Communications,2007,8:2243. |
| [6] | Jing G H;Li J H;Yang D;Hao J M .[J].Applied Catalysis B:Environmental,2009,91:123. |
| [7] | Suprun W;Schaedlich K;Papp H .SCR of NO on sulfated zirconium oxides in the presence of methane[J].Chemical Engineering & Technology: Industrial Chemistry -Plant Equipment -Process Engineering -Biotechnology,2005(2):199-203. |
| [8] | Sowade T;Liese T;Schmidt C;Schutze F W Yu X Bemdt H Grunert W .[J].Journal of Catalysis,2004,225:105. |
| [9] | Li, JH;Hao, JM;Cui, XY;Fu, LX .Influence of preparation methods of In2O3/Al2O3 catalyst on selective catalytic reduction of NO by propene in the presence of oxygen[J].Catalysis Letters,2005(1/2):75-82. |
| [10] | Maunula T;Ahola J;Hamada H .[J].Applied Catalysis B:Environmental,2006,64:13. |
| [11] | Wu C.;Wu F.;Chen LQ.;Huang XJ.;Wang ZX. .Spectroscopic studies on cation-doped spinel LiMn2O4 for lithium ion batteries[J].Solid state ionics,2001(3/4):277-285. |
| [12] | Weckhuysen B M;Schoonheydt R A;Jehna J M;Wachs E,Cho S J,Ryoo R,Kijlstra S,Poels E .[J].Journal of the Chemical Society,Faraday Transactions,1995,91:3245. |
| [13] | Gaspar A B;Brito J L F;Dieguez L C .[J].Journal of Molecular Catalysis A:Chemical,2003,203:251. |
| [14] | Jozwiak W K;Dalla-Lana I G .[J].Journal of the Chemical Society,Faraday Transactions,1997,93:2583. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%