Abstract: A CuZr slurry catalyst promoted by La and Mn additives was prepared by complete liquid-phase technology. The performance of the catalyst for direct synthesis of dimethyl ether from syngas was evaluated in a slurry reactor. The catalyst was characterized by NH₃ temperature-programmed desorption, powder X-ray diffraction, N₂ adsorption-desorption, X-ray photoelectron spectroscopy, and H₂ temperature-programmed reduction. The results indicated that the addition of La and Mn promoters to the CuZr slurry catalyst effectively improved the active metal dispersibility and increased the catalyst surface area. The presence of La and Mn also increased the surface vacancy of ZrO₂, improved the number of highly dispersed CuO and reducible CuO, and thereby enhanced the interaction between Cu and Zr. Consequently, the catalyst activity was obviously increased.

Key words: complete liquid-phase technology, copper, zirconium, slurry catalyst, lanthanum, manganese, promoter, syngas, dimethyl ether