Improved Preparation of Cu/Zn‐Based Catalysts by Well‐Defined Conditions of Co‐Precipitation and Aging

In order to enable science- and knowledge-based adaptation of catalyst materials to new demands, e.g., methanol synthesis from CO 2 , a modified method to prepare Cu/Zn-based catalysts based on the strict consecutive execution of co-precipita-tion and aging is investigated. By successfully stabilizing the initial co-precipitate, two mixing regimes are revealed: regarding slow mixing, the particle size of the co-precipitate decreases with increasing volume flow. By contrast, co-precipitation is no longer influenced by mixing for sufficiently high volume flows. While aging can be accelerated by forming smaller aggregates in the co-precipitation, the final state is found to be defined by thermodynamic equilibrium alone. Further-more, the microstructure of the final catalyst was influenced and the performance in direct dimethyl ether synthesis was improved by adjusting the mixing in the co-precipitation. We believe that the approach could be scaled-up to industrial production rates and, hence, is promising to make methanol synthesis from CO 2 more effective and sustainable. Research Article: Two mixing regimes in the continuous co-precipitation are revealed using a modified method to prepare Cu/Zn-based catalysts. Furthermore, the influence of mixing on aging kinetics, the microstructure development of the catalyst and the catalyst performance is investigated to evaluate the usefulness of our approach for adapting catalyst preparation to new demands on the material, possibly also at an industrial scale. .......... ¢

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