In Situ Infrared Molecular Detection Using Palladium-Containing Zeolite Films

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• 作者：S茅bastien Thomas ; Philippe Bazin ; Louwanda Lakiss ; Vincent de Waele ; Svetlana Mintova
• 刊名：Langmuir
• 出版年：2011
• 出版时间：December 6, 2011
• 年：2011
• 卷：27
• 期：23
• 页码：14689-14695
• 全文大小：1024K
• 年卷期：v.27,no.23(December 6, 2011)
• ISSN：1520-5827

文摘

In situ IR detection of carbon monoxide in the presence of hydrocarbons (methanol and pentane) using Pd-containing zeolite thin films is reported. The thin films are prepared by spin coating deposition of nanosized LTL and BEA type zeolites suspensions; the palladium clusters are introduced in the nanosized zeolites by ion exchange followed by 纬 radiolysis of the coating suspensions. The Pd-containing zeolite films with a thickness of 200 nm are exposed to a single gas (either CO or hydrocarbons) or gas mixtures in the presence of water (100 ppm), and the IR spectra are collected continuously at 25, 75, and 100 掳C. The fast recognition of very low concentrations of CO (2鈥?00 ppm) in the presence of highly concentrated vapors of methanol or pentane (400鈥?000 ppm) with the Pd-containing zeolite films is demonstrated. The detection of CO and hydrocarbons is instant, which is a function of the low thickness of the films, small size of the individual zeolite crystals, and regular size and high stability of the Pd clusters in the zeolite films. The heat of adsorption for all experiments is similar (15 kJ.mol<sup>鈥?sup>), which is explained with weak interactions between the carbon monoxide and palladium clusters in the zeolite films at temperatures below 100 掳C. The nanosized zeolites with homogeneously distributed Pd clusters deposited in thin films demonstrate high molecular recognition capacity toward low concentrations of carbon monoxide under real environmental conditions, i.e., in the presence of water and hydrocarbons.