Drastic Events and Gradual Change Define the Structure of an Active Copper‐Zinc‐Alumina Catalyst for Methanol Synthesis. Issue 15 (2nd March 2022)

• Record Type: Journal Article
• Authors: Beck, Arik; Newton, Mark A.; Zabilskiy, Maxim; Rzepka, Przemyslaw; Willinger, Marc G.; van Bokhoven, Jeroen A.
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 15(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-02
• Subjects: Activation -- CO2 Conversion -- Copper -- operando Analysis -- Zinc; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202200301
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The copper‐zinc‐alumina (CZA) catalyst is one of the most important catalysts. Nevertheless, understanding of the complex CZA structure is still limited and hampers further optimization. Critical to the production of a highly active and stable catalyst are optimal start‐up procedures in hydrogen. Here, by employing operando X‐ray absorption spectroscopy and X‐ray diffraction, we follow how the industrial CZA precursor evolves into the working catalyst. Two major events in the activation drastically alter the copper‐ and zinc‐containing components in the CZA catalyst and define the final working catalyst structure: the reduction of the starting copper(II) oxide, and the ripening and re‐oxidation of zinc oxide upon the switch to catalytic conditions. These drastic events are also accompanied by other gradual, structural changes. Understanding what happens during these events is key to develop tailored start‐up protocols that are aimed at maximal longevity and activity of the catalysts. Abstract : The origin of the high performance of the extensively used copper‐zinc‐alumina (CZA) catalyst for methanol synthesis is still unknown. How the catalyst is treated before use strongly determines its ultimate performance. Here, using combined operando X‐ray methods the evolution of the industrial CZA catalysts is followed and key events that define the final structure are identified.