Desorption study of NO and O2 on Cu-ZSM-5

被引:22
作者
Gervasini, A [1 ]
机构
[1] Univ Milan, Dipartimento Chim Fis & Elettrochim, I-20133 Milan, Italy
关键词
copper-ZSM-5; NO decomposition; nitrogen monoxide; oxygen; temperature-programmed desorption;
D O I
10.1016/S0926-3373(97)00019-2
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A detailed temperature-programmed desorption (TPD) study on NO and O-2 saturated Cu-ZSM-5 at different temperatures (300-723 K) has been performed. In the temperature range 373-723 K, the evolution of O-2 and NO2 accompanying the desorption of NO from NO saturated Cu-ZSM-5 suggested the formation of nitrite/nitrate species. The amount of O-2 adsorbed was very much lower than that of NO. The desorption profile of O-2 after contacting Cu-ZSM-5 with O-2 at 623 K showed a low temperature peak (369 K) confirming the spontaneous ability of O-2 desorption from copper zeolite. Moreover, successive saturation cycles of NO followed by O-2 and vice versa have been performed at various temperatures (298-623 K) to understand the modifications which the adsorption sites undergo when the two molecules NO and O-2 are available together for adsorption on the catalyst sites. After each saturation cycle, a TPD profile was recorded following the evolution of NO, O-2 and other NOx species. The competitive adsorption experiments revealed that, at 623 K, NO was not able to successfully compete with O-2 for the adsorption sites, therefore the adsorption of NO at 623 K on O-2 saturated catalyst was not completely restored. On the basis of the experimental work, an overall adsorption reaction scheme of NO on Cu-ZSM-5 was proposed. (C) 1997 Elsevier Science B.V.
引用
收藏
页码:147 / 159
页数:13
相关论文
共 28 条
[1]   OXYGEN INHIBITION IN DECOMPOSITION OF NO ON METAL-OXIDES AND PLATINUM [J].
AMIRNAZMI, A ;
BENSON, JE ;
BOUDART, M .
JOURNAL OF CATALYSIS, 1973, 30 (01) :55-65
[2]   DECOMPOSITION OF NITRIC-OXIDE ON PLATINUM [J].
AMIRNAZMI, A ;
BOUDART, M .
JOURNAL OF CATALYSIS, 1975, 39 (03) :383-394
[3]  
Bosch H., 1986, CATAL TODAY, V2, P369, DOI DOI 10.1016/0920-5861(88)80002-6
[4]   Adsorption of NO on Cu exchanged zeolites, an FTIR study: Effects of Cu levels, NO pressure, and catalyst pretreatment [J].
Cheung, T ;
Bhargava, SK ;
Hobday, M ;
Foger, K .
JOURNAL OF CATALYSIS, 1996, 158 (01) :301-310
[5]   COORDINATION OF CU IONS IN HIGH-SILICA ZEOLITE MATRICES - CU+ PHOTOLUMINESCENCE, IR OF NO ADSORBED ON CU2+, AND CU2+ ESR STUDY [J].
DEDECEK, J ;
SOBALIK, Z ;
TVARUZKOVA, Z ;
KAUCKY, D ;
WICHTERLOVA, B .
JOURNAL OF PHYSICAL CHEMISTRY, 1995, 99 (44) :16327-16337
[6]   TEMPERATURE-PROGRAMMED DESORPTION STUDY OF AMMONIA DESORPTION DIFFUSION IN MOLECULAR-SIEVES .1. THEORY [J].
FORNI, L ;
MAGNI, E .
JOURNAL OF CATALYSIS, 1988, 112 (02) :437-443
[7]   TEMPERATURE-PROGRAMMED DESORPTION STUDY OF AMMONIA DESORPTION DIFFUSION IN MOLECULAR-SIEVES .2. APPLICATION TO PARTIALLY DECATIONATED Y-ZEOLITES [J].
FORNI, L ;
MAGNI, E ;
ORTOLEVA, E ;
MONACI, R ;
SOLINAS, V .
JOURNAL OF CATALYSIS, 1988, 112 (02) :444-452
[8]   THE INTERACTION OF NO WITH COPPER IONS IN ZSM5 - AN EPR AND IR INVESTIGATION [J].
GIAMELLO, E ;
MURPHY, D ;
MAGNACCA, G ;
MORTERRA, C ;
SHIOYA, Y ;
NOMURA, T ;
ANPO, M .
JOURNAL OF CATALYSIS, 1992, 136 (02) :510-520
[9]  
HALL WK, 1992, CATAL LETT, V15, P311
[10]  
Iwamoto M., 1989, Stud. Surf. Sci. Catal, V44, P219