The beneficial use of ultrasound irradiation and nitrate/ acetate metal precursors in the co-precipitation synthesis and characterization of nanostructured CuO-ZnO-Al2O3 catalyst for methanol synthesis

摘要

A CuO-ZnO-Al2O3 catalyst was synthesized by an ultrasound assisted co-precipitation method and compared with the one synthesized by a conventional co-precipitation method. The characterization results of XRD, BET, FESEM and FTIR indicated that the physicochemical properties of the catalysts are strongly influenced by the formulated precursor and the synthesis method. The morphology of the catalyst precipitated under ultrasound irradiation was well-defined and ag-glomoration-free with average size particle of 32.3 nm. The dispersion of CuO and the surface area of the catalyst exhibited an improvement in acetate based catalyst. The high degree of synergism effect between CuO and other components in CuO-ZnO-Al2O3 catalyst was expected in the acetate-based catalyst synthesized with ultrasound assisted co-precipitation method due to low crystallinity and small size of copper species. The catalytic performance for the synthesis of methanol was examined at 200-300 °C and 10-40 bar in a stainless steel reactor. The CuO-ZnO-Al2O3 catalyst synthesized from acetate precursor precipitated under ultrasound irradiation exhibited a supreme catalytic activity at 275 °C, 40 bar, 18,000 cm~3/g h and H2/CO = 2 in terms of CO conversion and methanol yield.