CuO/ZnO nanoparticles in a matrix of amorphous silica as high-surface precursors for methanol synthesis

摘要

An intimate mixture of CuO/ZnO nanocrystals was prepared by an easy sol-gel synthesis (precipitation in methanol by hydroxide in the presence of a silane). The organic substituents of the silane were almost completely removed by a subsequent photochemical oxidation. The resulting amorphous SiO2 prevented the growth of the catalytically active particles to larger crystals. The coating layer of silica can easily be penetrated by gaseous reactants, as shown by the high specific surface area of about 110-130 m(2) g(-1) (probably due to both silica and nanocrystalline CuO/ZnO) and the good catalytic activity in methanol synthesis from CO/CO2/H-2 synthesis gas (7 to 37%, compared to an industrial standard methanol catalyst). The ratio of CuO to ZnO can be easily varied by the used preparation method. (C Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).