Abstract: The effect of CO2 concentration on the stability of the Cu-based catalyst was studied under the reaction conditions of 260 ℃, 5.0 MPa, and4000h-1. High concentration CO2 caused rapid deactivation of the Cu-based catalyst. Temperature-programmed reduction, N2 adsorption, elemental analysis, transmission electron microscopy, andX-rayphotoelectron spectroscopy were used to characterize the reduction behavior, surface physical properties, components, and surface morphologies of the Cu-based catalyst. Under the reaction condition of high CO2 concentration, the catalyst particle size increased and the total pore volume and BET surface area decreased greatly. There was significant metal loss of Zn and Al, and the synergistic effect between Cu and ZnO became weaker under the one-step slurry phase dimethyl ether synthesis conditions. High concentration CO2 restrained carbon deposition to some extent.

Key words: carbon dioxide, slurry reactor, dimethyl ether synthesis, methanol synthesis, Cu-based catalyst, stability