Abstract: The Cu-Zn-Al bifunctional slurry catalyst was prepared by a complete liquid phase method and characterized byX-raydiffraction,N2 adsorption,X-rayphotoelectron spectroscopy, and H2 temperature-programmed reduction. The effects of Al content and Cu/Zn molar ratio on the catalytic activity of the catalyst for dimethyl ether synthesis from syngas were investigated. The competitive enrichment of Zn and Al on the catalyst surface was dominating, and increasing the Cu content could not obviously increase the Cu amount on the catalyst surface. This is because Al was enriched faster on the catalyst surface than Cu under the reaction conditions in the case of the catalyst with higher Cu content. The catalyst withn(Cu)∶n(Zn)∶n(Al)=2∶1∶4 had the most favorable bulk structure and surface properties, such as the least Cu particle size, the highest dispersion degree, the excellent reductive character, the most strong interaction between metals, and the biggest probable pore radius. Therefore, this catalyst showed the best catalytic performance.

Key words: copper, zinc, aluminium, bifunctional catalyst, complete liquid phase method, carbon monoxide, hydrogenation, dimethyl ether