A QUANTUM-CHEMICAL STUDY OF ADSORBED NONCLASSICAL CARBONIUM-IONS AS ACTIVE INTERMEDIATES IN CATALYTIC TRANSFORMATIONS OF PARAFFINS .1. PROTOLYTIC CRACKING OF ETHANE ON HIGH-SILICA ZEOLITES

被引：57

作者：

KAZANSKY, VB ^{[1
]}

SENCHENYA, IN ^{[1
]}

FRASH, M ^{[1
]}

VANSANTEN, RA ^{[1
]}

机构：

[1] EINDHOVEN UNIV TECHNOL,SCHUIT INST CATALYSIS,5600 MB EINDHOVEN,NETHERLANDS

来源：

CATALYSIS LETTERS | 1994年 / 27卷 / 3-4期

关键词：

ZEOLITES; PROTONATION; CRACKING; QUANTUM CHEMISTRY; ACIDITY;

D O I：

10.1007/BF00813921

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：

Ab initio quantum-chemical calculations of protolytic cracking of ethane on Bronsted acid sites of high silica zeolites demonstrated the concerted mechanism of this reaction. The reaction coordinate represents the stretching of the O-H bond in combination with heterolytic splitting of the C-C ethane bond. This results in formation of methane and adsorption of the methyl group on the surface basic oxygen of the active site. The geometry of such activated complex is different from that of adsorbed carbonium ions which also represent highly excited surface complexes.

引用

页码：345 / 354

页数：10

共 16 条

[1]

BOHME DK, 1975, INTERACTION IONS MOL

[2] COMPUTATIONAL STUDIES OF ACID SITES IN ZSM-5 - DEPENDENCE ON CLUSTER SIZE [J].

BRAND, HV ;

CURTISS, LA ;

ITON, LE .

JOURNAL OF PHYSICAL CHEMISTRY, 1992, 96 (19) :7725-7732

[3] HETEROGENEITY OF OH GROUPS IN NAH-ZSM-5 ZEOLITE STUDIES BY INFRARED-SPECTROSCOPY [J].

DATKA, J ;

BOCZAR, M ;

RYMAROWICZ, P .

JOURNAL OF CATALYSIS, 1988, 114 (02) :368-376

[4]

Haag W. O., 1984, 8TH P INT C CAT BERL, VII, P305

[5]

Hehre W. J., 1985, AB INITIO MOL ORBITA

[6] STABILITIES AND ENERGETICS OF PENTACOORDINATED CARBONIUM-IONS - ISOMERIC C2H7+ IONS AND SOME HIGHER ANALOGS - C3H9+ AND C4H11+ [J].

HIRAOKA, K ;

KEBARLE, P .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1976, 98 (20) :6119-6125

[7]

KAZANSKY VB, 1991, CATAL LETT, V8, P317

[8] UNDERSTANDING THE ACID BEHAVIOR OF ZEOLITES FROM THEORY AND EXPERIMENT [J].

KRAMER, GJ ;

VANSANTEN, RA ;

EMEIS, CA ;

NOWAK, AK .

NATURE, 1993, 363 (6429) :529-531

[9] MONOMOLECULAR AND BIOMOLECULAR MECHANISMS OF PARAFFIN CRACKING - N-BUTANE CRACKING CATALYZED BY HZSM-5 [J].

KRANNILA, H ;

HAAG, WO ;

GATES, BC .

JOURNAL OF CATALYSIS, 1992, 135 (01) :115-124

[10] DETERMINATION OF PROTON AFFINITY OF ZEOLITES AND ZEOLITE-LIKE SOLIDS BY LOW-TEMPERATURE ADSORPTION OF CARBON-MONOXIDE [J].

KUBELKOVA, L ;

BERAN, S ;

LERCHER, JA .

ZEOLITES, 1989, 9 (06) :539-543

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