Periodic ab initio study of the oxidizing sites in Ti-containing zeolites

被引：19

作者：

ZicovichWilson, C ^{[1
]}

Dovesi, R ^{[1
]}

机构：

[1] UNIV POLITECN VALENCIA, CSIC, INST TECNOL QUIM, E-46071 VALENCIA, SPAIN

来源：

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL | 1997年 / 119卷 / 1-3期

关键词：

zeolites; titanium; ab initio; periodic; Hartree-Fock; chabazite;

D O I：

10.1016/S1381-1169(96)00508-0

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 periodic Hartree-Fock study of Ti-containing zeolites was performed. The zeolitic framework was modeled by means of the chabazite structure. Two framework compositions were considered (Ti/(Si + Ti) = 0 and 0.5) and the corresponding periodic structures were optimized in order to evaluate the structural and electronic features of the Ti sites. Cluster models were also considered for comparison. Despite the high Ti concentration, the theoretical cell expansion coefficient, 0.394, agrees very well with accurate experimental values. The adsorption of a single water molecule on a Ti site was studied and it was observed that a 5-fold coordination holds for the Ti atom in a deformed trigonal dipyramid.

引用

页码：449 / 458

页数：10

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