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One of the main stumbling blocks in developing rational design strategies for heterogeneous catalysis is that the complexity of the catalysts impairs efforts to characterize their active sites. We show how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al(2)O(3) methanol synthesis catalyst by using a combination of experimental(More)
Copper-based catalysts are industrially applied in various reactions including water-gas shift, synthesis of fatty alcohols from fatty acid methyl esters, and methanol synthesis. Today, methanol is produced at low pressures (35-55 bar) and 200-300°C over Cu/ZnO/Al2O3 catalysts. Due to the great commercial relevance, Cu/ZnO-based catalysts have been(More)
A pure ZnO sample and a sample containing 3 mol% Al were prepared by (co)-precipitation as model materials for the oxidic support phase in Cu/ZnO/Al(2)O(3) methanol synthesis catalysts. The samples were characterized with respect to their crystal, defect and micro-structure using various methods (XRD, TEM, XPS, UV-vis spectroscopy, EPR, NMR). It was found(More)
The results of experimental investigations of temperature oscillation spectra in the regions of active biological points when the state of the involved meridians is changed, have been presented. When the meridian is activated, the enhancement of the harmonics with the period 3-4 s has been observed in the spectra. The particular measuring technique and the(More)
A Cu-based methanol synthesis catalyst was obtained from a phase pure Cu,Zn,Al hydrotalcite-like precursor, which was prepared by co-precipitation. This sample was intrinsically more active than a conventionally prepared Cu/ZnO/Al2O3 catalyst. Upon thermal decomposition in air, the [(Cu0.5Zn0.17Al0.33)(OH)2(CO3)0.17]⋅mH2O precursor is transferred into a(More)
A technique of contact angle measurement was applied to the nano-scale oxide-supported metal particles. For Cu supported on ZnO and ZrO2 the angles were found to increase and the work of adhesion to decrease with increasing particle size. Such a trend is interpreted as an effect of negative contact line tension of 2.1 x 10(-9) J m(-1) and 1.0 x 10(-9) J(More)
Nanostructured Cu(x)Zn(1-x)Al(2)O(4) with a Cu:Zn ratio of ¼:¾ has been prepared by a microwave-assisted hydrothermal synthesis at 150 °C and used as a precursor for Cu/ZnO/Al(2)O(3)-based catalysts. The spinel nanoparticles exhibit an average size of approximately 5 nm and a high specific surface area (above 250 m(2) g(-1)). Cu nanoparticles of an average(More)
Different surface sites of solid catalysts are usually quantified by dedicated chemisorption techniques from the adsorption capacity of probe molecules, assuming they specifically react with unique sites. In case of methanol synthesis catalysts, the Cu surface area is one of the crucial parameters in catalyst design and was for over 25 years commonly(More)
High-performance Cu/ZnO/(Al(2)O(3)) methanol synthesis catalysts are conventionally prepared by co-precipitation from nitrate solutions and subsequent thermal treatment. A new synthesis route is presented, which is based on similar preparation steps and leads to active catalysts, but avoids nitrate contaminated waste water.