Paraffin dehydrocyclization: Isotope effect and competitive conversion of alkane/naphthene mixture with a Pt-Mg(Al) oxide catalyst

被引：9

作者：

Wang, YG ^{[1
]}

Shi, BC ^{[1
]}

Guthrie, RD ^{[1
]}

Davis, BH ^{[1
]}

机构：

[1] UNIV KENTUCKY, CTR APPL ENERGY RES, LEXINGTON, KY 40511 USA

来源：

JOURNAL OF CATALYSIS | 1997年 / 170卷 / 01期

关键词：

D O I：

10.1006/jcat.1997.1724

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 kinetic isotope effect and the lack of deuterium-hydrogen exchange in the unconverted reactants show that chemisorption of the reactant is the slow step of the dehydrocyclization mechanism with a Pt-SiO2 catalyst. While the chemisorption was nearly irreversible for a Pt-SiO2 catalyst, this was not the case for a Pt-Sn-SiO2 and Pt-Mg(Al)O catalysts. Data from the competitive conversion of a mixture of n-C8H18 and n-C8D18 show that there is a kinetic isotope effect for the dehydrocyclization reaction and that the magnitude of the effect for Pt-Mg(Al)O (similar to 2.0) falls between those of Pt-SiO2 and Pt-Sn-SiO2. The slight reversibility of the chemisorption step indicates that the Mg(AI)O support interacts with Pt but not to the extent that tin does in a silica-supported catalyst with a Pt:Sn = 1 : 1 ratio. The kinetic isotope effect for Pt-Mg(Al)O is about 2 and is comparable to the one obtained with a Pt-Sn-SiO2 catalyst but is considerably lower than the value of 3.5 obtained with a Pt-SiO2 catalyst. (C) 1997 Academic Press.

引用

页码：89 / 95

页数：7