以La改性的Al2O3为载体，采用共吸附浸渍法制备了一系列不同CeO2含量的单Pd密偶催化剂，并对其进行了表征。 PdOx和CeO2之间的强相互作用改善了Pd0再氧化为PdO的能力，同时增强了反应条件下硝酸盐，亚硝酸盐和异氰酸盐在载体上的吸附。因
此适量CeO2的添加明显改善了新鲜催化剂对HC和NOx的催化性能，且当CeO2添加量为2%时催化效果最佳。 Pd-Ce界面上PdOx和CeO2间强相互作用也使得PdOx物种在高温时仍能以小颗粒的形式分散在载体上，从而显著地提高催化剂的热稳定性。经1100°C高温老化后， CeO2(2%-4%)的存在明显拓宽了HC和NOx的操作窗口，这对于提高单Pd密偶催化剂在汽车尾气处理上的催化性能有重要意义。
A series of La-Al2O3 supported Pd-Ce close-coupled catalysts were synthesized by a co-adsorption impregnation method and subsequently investigated. In the case of fresh catalysts, the presence of an optimal concentration of ceria obviously promoted the catalytic activity during HC and NOx eliminations, owing to the interaction between the palladium oxide species (PdOx) and CeO2 that improves the oxidation of Pd0 to PdO and enhances the adsorption of nitrite/nitrates and isocyanate intermediate species on the support under reaction conditions. Pd-Ce(2.0)/La-Al2O3 catalyst (where 2.0 is the wt%of CeO2) exhibited the highest catalytic activity for HC and NO eliminations. Following aging at 1100 °C, the operational window for HC and NOx conversions was broadened and the thermal stability of the catalysts was also improved as a result of the presence of an appropriate quantity of ceria (2.0-4.0 wt%). The enhanced interactions between PdOx and CeO2 evidently led to the formation of a Pd-O-Ce system, stabilizing PdOx species with smaller particle sizes at high tem-peratures. This result is significant since it suggests a means of improving the catalytic performance of Pd-only close-coupled catalysts during automobile exhaust elimination.
参考文献
| [1] | 赵波,王秋艳,葛昌华,李光凤,周仁贤.Ce0.67Zr0.33O2材料的制备和表征及其负载单Pd三效催化剂的性能[J].催化学报,2009(05):407-413. |
| [2] | 崔亚娟,何胜楠,方瑞梅,史忠华,龚茂初,陈耀强.整体式Pd/La2O3-Al2O3和Pd/CeO2-ZrO2-Y2O3催化剂上汽油车尾气净化性能的比较[J].催化学报,2012(06):1020-1026. |
| [3] | Hungría A B;Calvino J J;Anderson J A;Martínez-Arias A .[J].Applied Catalysis B:Environmental,2006,62:359. |
| [4] | Lafyatis D S;Ansell G P;Bennett S C;Frost J C Millington P J Rajaram R R Walker A P Ballinger T H .[J].Applied Catalysis B:Environmental,1998,18:123. |
| [5] | Zhu Z Z;Lu G Z;Guo Y;Guo Y L Zhang Z G Wang Y Q .[J].Journal of Industrial and Engineering Chemistry,2012,18:2135. |
| [6] | Cargnello M;Jaen J J D;Garrido J C H;Bakhmutsky K Montini T Gamez J J C Gorte R J Fornasiero P .[J].SCIENCE,2012,337:713. |
| [7] | Bounechada D;Groppi G;Forzatti P;Kallinen K Kinnunen T .[J].Applied Catalysis B:Environmental,2012,119-120:91. |
| [8] | Shan W P;Liu F D;He H;Shi X Y Zhang C B .[J].Chemistry Communications,2011,47:8046. |
| [9] | 刘福东,单文坡,石晓燕,张长斌,贺泓.用于NH3选择性催化还原NO的非钒基催化剂研究进展[J].催化学报,2011(07):1113-1128. |
| [10] | Cao Y D;Ran R;Wu X D;Zhao B H Wan J Weng D .[J].Applied Catalysis A:General,2013,457:52. |
| [11] | 闫朝阳,兰丽,陈山虎,赵明,龚茂初,陈耀强.高性能Ce0.5Zr0.5O2稀土储氧材料的制备及其负载的单Pd三效催化剂[J].催化学报,2012(02):336-341. |
| [12] | 陈山虎,姚艳玲,兰丽,曹毅,闫朝阳,龚茂初,陈耀强.不同锆源对Pd/Ce0.45Zr0.45La0.1O1.95整体式三效催化剂性能的影响[J].催化学报,2012(11):1762-1771. |
| [13] | Colussi S;Gayen A;Farnesi Camellone M;Boaro M Llorca J Fabris S Trovarelli A .[J].ANGEWANDTE CHEMIE-INTERNATIONAL EDITION,2009,48:8481. |
| [14] | Martinez-Arias A;Fernandez-Garcia M;Salamanca L N;Valenzuela R X Conesa J C Soria J .[J].Journal of Physical Chemistry B,2000,104:4038. |
| [15] | Venancio S A;de Miranda P E V .[J].CERAMICS INTERNATIONAL,2011,37:3139. |
| [16] | Damyanova S;Perez C A;Schmal M;Bueno J M C .[J].Applied Catalysis A:General,2002,234:271. |
| [17] | Mira C;Calvino J J;Pérez-Omil J A;Rodríguez-Izquierdo J M Bernal S .[J].Catalysis Today,2012,180:174. |
| [18] | Cargnello M;Wieder N L;Canton P;Montini T Giambastiani G Benedetti A Gorte R J Fornasiero P .[J].CHEMISTRY OF MATERIALS,2011,23:3961. |
| [19] | Cargnello M;Wieder N L;Montini T;Gorte R J Fornasiero P .[J].Journal of the American Chemical Society,2010,132:1402. |
| [20] | Wang Y P;Zhao J S;Wang X L;Li Z Liu P F .[J].Bulletin of the Korean Chemical Society,2013,34:2461. |
| [21] | Baylet A;Royer S;Marécot P;Tatibou?t J M Duprez D .[J].Applied Catalysis B:Environmental,2008,81:88. |
| [22] | Li Y;Zhang X Y;Long E Y;Li H M Wu D D Cai L Gong M C Chen Y Q .[J].Journal of Natural Gas Chemistry,2009,18:415. |
| [23] | Zhao B;Yang C Q;Wang Q Y;Li G F Zhou R X .[J].Journal of Alloys and Compounds,2010,494:340. |
| [24] | Wang J Q;Shen M Q;An Y;Wang J .[J].CATALYSIS COMMUNICATIONS,2008,10:103. |
| [25] | Wang Q Y;Li G F;Zhao B;Zhou R X .[J].Applied Catalysis B:Environmental,2010,100:516. |
| [26] | Osorio G P;Moyado S F;Petranovskii V;Simakov A .[J].Catalysis Letters,2006,110:53. |
| [27] | Fernández-Garc;Iglesias-Juez A;Mart;Hungr Anderson J A Conesa J C Soria J .[J].Journal of Catalysis,2004,221(a A B):594. |
| [28] | Gaudet J R;de la Riva A;Peterson E J;Bolin T Datye A K .[J].ACS Catal,2013,3:846. |
| [29] | Yoshida H;Narisawa S;Fujita S;Ruixia L Arai M .[J].Physical Chemistry Chemical Physics,2012,14:4724. |
| [30] | Cárdenas-Lizana, F.;Gómez-Quero, S.;Hugon, A.;Delannoy, L.;Louis, C.;Keane, M.A. .Pd-promoted selective gas phase hydrogenation of p-chloronitrobenzene over alumina supported Au[J].Journal of Catalysis,2009(2):235-243. |
| [31] | Alexeev O S;Krishnamoorthy S;Jensen C;Ziebarth M S Yaluris G Roberie T G Amiridis M D .[J].Catalysis Today,2007,127:189. |
| [32] | Macleod N;Lambert R M .[J].Applied Catalysis B:Environmental,2003,46:483. |
| [33] | Faria W L S;Perez C A C;César D V;Dieguez L C Schmal M .[J].Applied Catalysis B:Environmental,2009,92:217. |
| [34] | Baidya, T.;Bera, P.;Mukri, B.D.;Parida, S.K.;Kr?cher, O.;Elsener, M.;Hegde, M.S..DRIFTS studies on CO and NO adsorption and NO + CO reaction over Pd 2+-substituted CeO_2 and Ce_(0.75)Sn _(0.25)O_2 catalysts[J].Journal of Catalysis,2013:117-129. |
| [35] | Hirano T;Ozawa Y;Sekido T;Ogino T Miyao T Naito S .[J].Applied Catalysis A:General,2007,320:91. |
| [36] | Oh H;Luo J Y;Epling W S .[J].Catalysis Letters,2011,141:1746. |
| [37] | Meunier F C;Zuzaniuk V;Breen J P;Olsson M Ross J R H .[J].Catalysis Today,2000,59:287. |
| [38] | Abdulhamid H;Dawody J;Fridell E;Skoglundh M .[J].Journal of Catalysis,2006,244:169. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%