Structural and catalytic properties of sodium and cesium exchanged X and Y zeolites, and germanium-substituted X zeolite

被引:47
作者
Concepción-Heydorn, P [1 ]
Jia, C [1 ]
Herein, D [1 ]
Pfander, N [1 ]
Karge, HG [1 ]
Jentoft, FC [1 ]
机构
[1] Max Planck Gesell, Fritz Haber Inst, Dept Inorgan Chem, D-14195 Berlin, Germany
关键词
alkali metal cation exchanged faujasite-type zeolites; isopropanol dehydrogenation; infrared spectroscopy; X-ray diffraction; CO2; adsorption;
D O I
10.1016/S1381-1169(00)00292-2
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
The conversion of isopropanol in a fixed bed flow reactor was used as a test reaction for a number of faujasite-type zeolites which were modified in order to increase their basicity. Samples included a CsY zeolite with an intact faujasite structure and an exchange degree of nearly 100% prepared by solid-state ion exchange, a CsNaY obtained from CsY through exchange with aqueous NaCl solution, a CsNaX obtained from NaX and aqueous CsCl solution, and a Na(Ge)X, with Si replaced by Ge. At 623 K, an isopropanol partial pressure of 5 kPa in He, and a total feed flow of 90 ml/min, a catalyst mass of 50 mg, initial yields were as follows: NaY: 62% propene, CsNaY: 78% propene, NaCsX: 10% propene, 0.37% acetone, Na(Ge)X: 8% propene, 11% acetone. Conversion in the presence of CsY was < 1%. CO2 adsorption and infrared (IR) spectroscopy were used to probe basicity, and Na(Ge)X was the only sample to form monodentate carbonates upon CO2 adsorption (bands at 1477 and 1428 cm(-1)). Further characterization with X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal analysis, nitrogen sorption, and isopropanol sorption was necessary to properly interpret catalytic results by identifying samples which contained impurities, had blocked pore systems, or decomposed partially during activation or reaction. (C) 2000 Elsevier Science B.V. All rights reserved.
引用
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页码:227 / 246
页数:20
相关论文
共 60 条
[21]  
HUBER S, 1997, THESIS LUDWIG MAXIMI
[22]   ACTIVE-SITES IN ZEOLITES .7. ISOPROPANOL DEHYDROGENATION OVER ALKALI CATION-EXCHANGED X-ZEOLITE AND Y-ZEOLITE [J].
JACOBS, PA ;
UYTTERHOEVEN, JB .
JOURNAL OF CATALYSIS, 1977, 50 (01) :109-114
[23]   ACTIVE-SITES IN ZEOLITES .6. ALCOHOL DEHYDRATION OVER ALKALI CATION-EXCHANGED X-ZEOLITE AND Y-ZEOLITE [J].
JACOBS, PA ;
TIELEN, M ;
UYTTERHOEVEN, JB .
JOURNAL OF CATALYSIS, 1977, 50 (01) :98-108
[24]   SURFACE PROBING OF SYNTHETIC FAUJASITES BY ADSORPTION OF CARBON-DIOXIDE .1. INFRARED STUDY OF CARBON-DIOXIDE ADSORBED ON NA-CA-Y AND NA-MG-Y ZEOLITES [J].
JACOBS, PA ;
VANCAUWE.FH ;
VANSANT, EF ;
UYTTERHO.JB .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1973, 69 :1056-1068
[25]   SURFACE PROBING OF SYNTHETIC FAUJASITES BY ADSORPTION OF CARBON-DIOXIDE .2. INFRARED STUDY OF CARBON-DIOXIDE ADSORBED ON X ZEOLITES EXCHANGED WITH MONOVALENT AND BIVALENT IONS [J].
JACOBS, PA ;
VANCAUWE.FH ;
VANSATN, EF .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I, 1973, 69 (12) :2130-2139
[26]  
JIA C, 1997, INT S AC BAS CAT 3 R
[27]  
KARGE HG, 1991, STUD SURF SCI CATAL, V69, P43
[28]   First observation of the broad-range DRIFT spectra of carbon dioxide adsorbed on NaX zeolite [J].
Kazansky, VB ;
Borovkov, VY ;
Serykh, AI ;
Bulow, M .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 1999, 1 (15) :3701-3702
[29]  
KIM JC, 1994, MICROPOROUS MATER, V2, P413
[30]   INSITU INFRARED STUDY OF ALKYLATION OF TOLUENE WITH METHANOL ON ALKALI CATION-EXCHANGED ZEOLITES [J].
KING, ST ;
GARCES, JM .
JOURNAL OF CATALYSIS, 1987, 104 (01) :59-70