Abstract: The Cu-based catalyst (500 g) for methanol synthesis was prepared by an acid-alkali alternate precipitation method. The catalyst samples were characterized by means ofX-raydiffraction, N2 adsorption, scanning electron microscopy, oxygen chemisorption, and H2 temperature-programmed reduction. The effects of the stirring speed, the trickle speed of solution, and the concentration of alkali and metal salt solution on the catalytic performance of the Cu-based catalyst for methanol synthesis were studied. The amorphous CuO-ZnO solid solution was formed in the catalyst, and itsX-raydiffraction was weakened and broadened, indicating the lower crystallization degree. The size of CuO and ZnO crystallites was decreased, the catalyst grains became smaller, and its particle size distribution was more homogeneous. The existence of amorphous CuO-ZnO solid solution could increase the BET surface area of the catalyst. The catalyst prepared by the acid-alkali alternate precipitation method showed higher Cu dispersion and bigger Cu surface area. Under the optimized preparation conditions, the Cu-based catalyst prepared in this work was higher than other domestic and foreign industrial catalysts in activity and thermal stability.

Key words: acid-alkali alternate precipitation, methanol synthesis, copper-based catalyst, optimization, characterization