Preparation and properties of cerium modified Cu-based catalysts for methanol synthesis

Cerium modified Cu-based catalysts (CuZnAlCe) for methanol synthesis from syngas were prepared by anti-coprecipitation method with Na₂CO₃ solution as a precipitant, Cu(NO₃)₂, Zn(NO₃)₂ and Al₂(NO₃)₃ solution as raw materials. The structure and morphology of CuZnAlCe were studied by X-ray diffraction, thermal gravimetry-differential thermal analysis, N₂ adsorption-desorption measurement, scanning electron microscopy, and temperature programmed reduction. The catalytic activities of the prepared catalysts for methanol synthesis were evaluated on micro fixed-bed reaction system. It showed that the addition of Ce improved the dispersion of active sites and provided a high surface area, which play an important role in the stability and activity of CuZnAlCe. The CO conversion reached an optimum value to 47.6% over the Ce modified Cu-based catalyst at the Cu/Ce molar ratio of 1:0.02, while the catalytic activity and stability decreased when the loading of Ce was excessive. Proper loadings of Ce could improve the thermal stability of Cu-based catalysts.