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Methanol Synthesis over Cu/ZnO Catalysts Prepared by Ball MillingHuang, L.; Kramer, G.J.; Wieldraaijer, W.; Brands, D.S.; Poels, E.K.; Castricum, H.L.; Bakker, H. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Cu/ZnO catalysts (with a Cu/Zn atomic ratio of 30/70) have been prepared by high intensity mechanical mixing of copper and zinc oxide powder in air and under vacuum. During milling in vacuum gradual amorphisation of the constituents occurs, as evidenced by broadening of the Cu 0 and ZnO diffraction peaks in XRD, but the two original phases remain. The result of such treatment is a catalyst with low BET area and low Cu metal surface area. Consequently, the activity of the vacuum milled samples in batch methanol production from synthesis gas (CO/CO 2 /H 2 20/5/75) at 50 bar and 250 C is low. Milling in air leads to oxidation of the copper metal phase and much higher BET surface area and, after reduction, Cu metal surface area. Prolonged milling times in air result in more than 90% Cu 2 formation as evidenced by TPR. Activity in methanol synthesis for the air milled samples is comparable to a conventional Cu/ZnO catalyst prepared by coprecipitation. It is concluded that high intensity ball milling at ambient conditions is a promising method to prepare mixed oxide catalysts or catalyst precursors.

The deposition of Cu, Zn, Pt, and Co precursor particles from solution onto a flat silicon wafer using a spin coater was studied. Homogeneously distributed monodisperse particles can be obtained. The dependence of particle size and number density on solution concentration and rotation frequency was investigated. Different solvents and support modifications were studied. The particles were analyzed using dark-field microscopy, scanning electron microscopy, and atomic force microscopy.