Determining Number of Active Sites and TOF for the High-Temperature Water Gas Shift Reaction by Iron Oxide-Based Catalysts

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• 作者：Minghui Zhu ; Israel E. Wachs
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：March 4, 2016
• 年：2016
• 卷：6
• 期：3
• 页码：1764-1767
• 全文大小：274K
• ISSN：2155-5435

文摘

This study demonstrates, with C¹⁶O₂/C¹⁸O₂ isotope switch and H₂-TPR experiments, for the first time that (i) the high-temperature water–gas shift (HT-WGS) reaction by copper–chromium-iron oxide catalysts follows a redox mechanism dominated by the surface layer, (ii) the number of catalytic active sites can be quantified by the isotopic switch, and (iii) the turnover frequency (TOF) can be determined from knowledge of the number of sites. The quantitative TOF values reveal that chromium is only a textural promoter, whereas copper is a chemical promoter.