Dichloromethane transformation over bifunctional PtFAU catalysts. Influence of the acidobasicity of the zeolite

被引：15

作者：

Pinard, L ^{[1
]}

Mijoin, J ^{[1
]}

Magnoux, P ^{[1
]}

Guisnet, M ^{[1
]}

机构：

[1] Fac Sci, CNRS, UMR 6503, Catalyse Chim Organ Lab, F-86022 Poitiers, France

来源：

COMPTES RENDUS CHIMIE | 2005年 / 8卷 / 3-4期

关键词：

chlorinated VOCs; catalytic oxidation; platinum zeolites; NaY; NaX; USHY;

D O I：

10.1016/j.crci.2004.10.002

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The catalytic oxidation of dichloromethane (DCM) was investigated over PtNaX and PtNaY catalysts with different amounts and dispersions of Pt under the following conditions: fixed bed reactor, 1000 ppm of DCM in wet air, space velocity of 20,000 h(-1), temperature between 220 and 450 degrees C. It is shown that Pt has only a limited effect on DCM conversion but causes a significant change in the product composition; the only role of Pt is to oxidise formaldehyde resulting from DCM hydrolysis on the zeolite support. DCM hydrolysis was carried out over a series of FAU zeolites: NaX, LiY, NaY, KY, CsY and USHY. The hydrolysis rate was shown to increase significantly with the zeolite basicity. A general reaction mechanism is proposed involving mainly the transformation of DCM species adsorbed on acido (H+, alcaline cation) basic (zeolite, framework oxygens) sites into chloromethoxy then hydroxymethoxy species. (c) 2005 Academie des sciences. Published by Elsevier SAS. All rights reserved.

引用

页码：457 / 463

页数：7

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