Performance Improvement of Nanocatalysts by Promoter-Induced Defects in the Support Material: Methanol Synthesis over Cu/ZnO:Al

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• 作者：Malte Behrens ; Stefan Zander ; Patrick Kurr ; Nikolas Jacobsen ; J眉rgen Senker ; Gregor Koch ; Thorsten Ressler ; Richard W. Fischer ; Robert Schl枚gl
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：April 24, 2013
• 年：2013
• 卷：135
• 期：16
• 页码：6061-6068
• 全文大小：414K
• 年卷期：v.135,no.16(April 24, 2013)
• ISSN：1520-5126

文摘

Addition of small amounts of promoters to solid catalysts can cause pronounced improvement in the catalytic properties. For the complex catalysts employed in industrial processes, the fate and mode of operation of promoters is often not well understood, which hinders a more rational optimization of these important materials. Herein we show for the example of the industrial Cu/ZnO/Al₂O₃ catalyst for methanol synthesis how structure鈥損erformance relationships can deliver such insights and shed light on the role of the Al promoter in this system. We were able to discriminate a structural effect and an electronic promoting effect, identify the relevant Al species as a dopant in ZnO, and determine the optimal Al content of improved Cu/ZnO:Al catalysts. By analogy to Ga- and Cr-promoted samples, we conclude that there is a general effect of promoter-induced defects in ZnO on the metal鈥搒upport interactions and propose the relevance of this promotion mechanism for other metal/oxide catalysts also.