在富氧条件下Ag/Al2O3对以丙烯为还原剂选择性催化还原NOx的反应有很高的催化活性. 本实验成功地利用原位红外光谱分析手段,在真实的催化反应条件下,探讨了丙烯选择性还原NOx的反应机理,证实了催化剂表面反应中间体Al-NCO和Ag-NCO虽在真空中稳定,但在实际反应条件下极为活泼.催化剂表面上R-ONO和R-NO2分解成NCO是整个反应的速度控制步骤. 这一结论与在真空系统条件下对其反应机理的研究结果一致,证明了在这一反应体系中两种研究方法的相关性. 同时本实验还从反应机理上探讨了催化剂的水蒸气中毒现象. 水蒸气的存在阻碍了催化剂表面R-ONO和R-NO2的生成,并进一步阻碍了反应的速度控制步骤,即R-ONO和R-NO2向Al-NCO和Ag-NCO的转化,但这是一种完全可逆的暂时中毒现象. 结合相应的催化剂活性评价结果对表面反应机理进行了讨论.
参考文献
| [1] | Miyadera T .[J].Applied Catalysis B:Environmental,1998,16(02):155. |
| [2] | Sumiya S.;He H.;Feng QC.;Takezawa N.;Yoshida K.;Saito M. .Reduction of lean NOx by ethanol over Ag/Al-2O3 catalysts in the presence of H2O and SO2[J].Catalysis Letters,1998(1/2):87-91. |
| [3] | Meunier F C;Ross J R H .[J].Applied Catalysis B:Environmental,2000,24(01):23. |
| [4] | Miyadera T;Yoshida K.[J].Chemistry Letters,1993(09):1483. |
| [5] | 贺泓.环境多相催化研究过程中的表面科学研究方法[J].环境科学学报,2003(02):224-229. |
| [6] | Sumiya S;He H;Abe A;Takezawa N,Yoshida K .[J].Journal of the Chemical Society,Faraday Transactions,1998,94(15):2217. |
| [7] | Citra A;Andrews L .[J].Journal of Physical Chemistry A Molecules Spectroscopy Kinetics Environment and General Theory,2001,105(13):3042. |
| [8] | Meunier F C;Zuzaniuk V;Breen J P;Olsson M,Ross J R H .[J].Catalysis Today,2000,59:287. |
| [9] | Bion N.;Hedouin C.;Seguelong T.;Daturi M.;Saussey J. .Evidence by in situ FTIR spectroscopy and isotopic effect of new assignments for isocyanate species vibrations on Ag/Al2O3[J].Physical chemistry chemical physics: PCCP,2001(21):4811-4816. |
| [10] | HeH;Yu Y B.[J].Applied Catalysis B:Environmental |
| [11] | Yamaguchi M .[J].Journal of the Chemical Society,Faraday Transactions,1997,93(19):3581. |
| [12] | Saliba N;Wang J;Bansenauer B A;Koel B E .[J].Surface Science Spectra,1997,389:147. |
| [13] | Haneda M;Kintaichi Y;Inaba M;Hamada H .[J].Applied Surface Science,1997,121/122:391. |
| [14] | Tanaka T;Okuhara T;Misono M .[J].Applied Catalysis B:Environmental,1994,4(01):L1. |
| [15] | Bell V A;Feeley J S;Deeba M;Farruto R J .[J].Catalysis Letters,1994,29(04):15. |
| [16] | Shimizu K.;Yoshida H.;Satsuma A.;Hattori T.;Shibata J. .Silver-alumina catalysts for selective reduction of NO by higher hydrocarbons: structure of active sites and reaction mechanism[J].Applied Catalysis, B. Environmental: An International Journal Devoted to Catalytic Science and Its Applications,2001(1/2):151-162. |
| [17] | Kameoka S.;Miyadera T.;Ukisu Y. .Selective catalytic reduction of NOx with CH3OH, C2H5OH and C3H6 in the presence of O-2 over Ag/Al2O3 catalyst: Role of surface nitrate species[J].Physical chemistry chemical physics: PCCP,2000(3):367-372. |
| [18] | Meunier F C;Breen J P;Zuzaniuk V;Olsson M,Ross J R H .[J].Journal of Catalysis,1999,187(02):493. |
| [19] | Martínez-Arisa A;Fernández-García M;Iglesias-Juez A;Anderson J A,Conesa J C,Soria J .[J].Applied Catalysis B:Environmental,2000,28(01):29. |
| [20] | Shimizu K;Satsuma A;Hattori T .[J].Applied Catalysis B:Environmental,2000,25(04):239. |
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