用浸渍法制备了一种高效的Na-Rh/γ-Al2O3催化剂,应用X射线衍射、 X射线光电子能谱和N2吸附-脱附等技术手段对催化剂进行了表征,考察了该催化剂的CO选择氧化性能,同时考察了不同预处理条件对催化剂活性的影响. 在100 ℃,GHSV=2.25×104 h-1,原料气组成2%CO,1.4%O2和70%H2的条件下,5%Na-0.5%Rh/γ-Al2O3催化剂上CO转化率和CO2选择性分别高达100%和70%. 在饱和水蒸气存在时,CO转化率和CO2选择性可保持长达100 h不变,说明该催化剂有很好的稳定性和抗水性. 研究表明,Na原子可能通过向表面Rh提供电子,增强了Rh向CO的2π*分子轨道反馈电子的能力,使CO分子得到了活化. Na的添加在一定程度上提高了催化剂表面Rh的分散度,使其在高温条件下不易烧结. N2吸附-脱附结果表明,Na的存在虽然在一定程度上减小了催化剂的比表面积,但扩孔作用使催化剂平均孔径有明显的增大.
参考文献
| [1] | Oetjen H F;Schmidt V M;Stimming U;Trila F .[J].Journal of the Electrochemical Society,1996,143(12):3838. |
| [2] | Kahlich MJ.;Behm RJ.;Gasteiger HA. .KINETICS OF THE SELECTIVE CO OXIDATION IN H-2-RICH GAS ON PT/AL2O3[J].Journal of Catalysis,1997(1):93-105. |
| [3] | Oh S H;Sinkevitch R M .[J].Journal of Catalysis,1993,142(01):254. |
| [4] | Oh S H .[J].Journal of Catalysis,1990,124(02):477. |
| [5] | Igarashi H;Uchida H;Suzuki M;Sasaki Y Watanabe M .[J].Applied Catalysis A:General,1997,159(1-2):159. |
| [6] | Grisel R J H;Weststrate C J;Goossens A;Craj?M W J van der Kraan A M Nieuwenhuys B E .[J].Catalysis Today,2002,72(1-2):123. |
| [7] | Dou L Q;Tan Y Sh;Lu D Sh .[J].Applied Catalysis,1990,66(01):235. |
| [8] | Zhang R;Schwarz J A;Datye A;Baltrus J P .[J].Journal of Catalysis,1992,138(01):55. |
| [9] | 祁彩霞;安立敦;王弘立 .[J].分子催化,1998,12(06):429. |
| [10] | Shinichi M .[J].Catalysis Surveys From Japan,1997,1(01):111. |
| [11] | Takahashi N;Shinjoh H;Iijima T;Suzuki T Yamazaki K Yokota K et al.[J].Catalysis Today,1996,27(1-2):63. |
| [12] | Minemura Y;Kuriyama M;Ito S;Tomishige K Kunimori K .[J].Catalysis Communications,2006,7(09):623. |
| [13] | Mirkelamoglu B;Karakas G .The role of alkali-metal promotion on CO oxidation over PdO/SnO2 catalysts[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,2006(0):84-94. |
| [14] | Iwasa N;Arai S;Arai M .[J].Catalysis Communications,2006,7(11):839. |
| [15] | Tanaka H;Ito S;Kameoka S;Tomishige K Kunimori K .[J].Applied Catalysis A:General,2003,250(02):255. |
| [16] | 陈光文,李淑莲,袁权,焦凤君.钾助剂对Rh/Al2O3催化富氢条件下CO选择氧化反应性能的影响[J].催化学报,2005(09):809-814. |
| [17] | Iordan A.;Zaki MI.;Kappenstein C.;Geron C. .XPS and in situ IR spectroscopic studies of CO/Rh/Al2O3 and CO/Rh/K-Al2O3 at high temperatures: probing the impact of the potassium functionalization of the support[J].Physical chemistry chemical physics: PCCP,2003(8):1708-1715. |
| [18] | 赖伍江.合成甲醇铜基催化剂上助催剂与铜原子相互作用对CO活化效应的量子化学[J].厦门大学学报(自然科学版,1993(04):462. |
| [19] | Bonzel H P .[J].Surface Science Reports,1987,8(02):43. |
| [20] | Dubois L H;Zegarski B R;Luftman H S .[J].Journal of Chemical Physics,1987,87(02):1367. |
| [21] | Rodriguez J A;Campbell C T .[J].Journal of Physical Chemistry,1987,91(08):2161. |
| [22] | Miyoshi E;Sakai Y;Katsuki S .[J].Surface Science,1991,242(1-3):531. |
| [23] | Ojeda M;Granados M L;Rojas S;Terreros P Garcia-Garcia F J Fierro J L G .[J].Applied Catalysis A:General,2004,261(01):47. |
| [24] | Minemura Y;Ito S;Miyao T;Naito S;Tomishige K;Kunimori K .Preferential CO oxidation promoted by the presence of H-2 over K-Pt/Al2O3[J].Chemical communications,2005(11):1429-1431. |
| [25] | Pavlenko N.;Suchorski Y.;Imbihl R.;Kostrobij PP. .Alkali metal effect on catalytic CO oxidation on a transition metal surface: a lattice-gas model[J].Surface Science: A Journal Devoted to the Physics and Chemistry of Interfaces,2001(1/3):29-36. |
| [26] | Yakovkin I.N.;Naumovets A.G.;Chernyi V.I. .Oxidation of CO on Li-precovered Pt[J].Surface Science: A Journal Devoted to the Physics and Chemistry of Interfaces,1999(1):81-89. |
| [27] | Bergeld J;Kasemo B;Chakarov D V .[J].Surface Science,2001,495(03):L815. |
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