In Situ Real-Time Studies of Heterogeneous Catalytic Mechanisms at Ambient Pressures As Probed by Surface-Enhanced Raman and Mass Spectroscopies

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• 作者：Christopher T. Williams ; Ho Yeung H. Chan ; Anish A. Tolia ; Michael J. Weaver ; and Christos G. Takoudis
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：1998
• 出版时间：June 1998
• 年：1998
• 卷：37
• 期：6
• 页码：2307 - 2315
• 全文大小：257K
• 年卷期：v.37,no.6(June 1998)
• ISSN：1520-5045

文摘

The utility of surface-enhanced Raman spectroscopy (SERS) as an insitu adsorbate probe ofheterogeneous catalytic systems at high gas pressures (here up to 1atm) in conjunction withmass spectrometry (MS) is demonstrated for reactions ontransition-metal catalysts, attemperatures up to 500 C. This simultaneous SERS-MS approachenables the relationshipsbetween the formation of specific adsorbed species (as sensed by SERS)and reaction products(as detected by MS) to be explored on a common (1 s) time scale.The low-frequency (<1000cm^-1) spectral region, wheremetal-adsorbate vibrations are located, is especiallyinformative.The environmentally important reactions of NO reduction by CO orH₂ and the oxidation ofmethanol on transition metals (Rh, Pd, Pt) are considered here.The possible mechanisticsignificance of surface oxide formation observed during suchambient-pressure catalytic reactionsis also discussed.