Abstract: Compared with the traditional gas phase synthesis, slurry-phase synthesis of methanol has many advantages. The bottle neck for the commercialization of slurry-phase methanol synthesis is the catalyst deactivation. In this paper, the stability and deactivation of a commercial Cu-based C301 catalyst for methanol synthesis from syngas with paraffin in a slurry phase were studied using a stirred autoclave reactor system. Synthesis reactions were conducted under the conditions of 5 MPa, 260 ℃, and 1?100 ml/(g•h), and the reactions were lasted for different times to obtain catalyst samples with different deactivation degrees. The composition and morphology of the catalyst samples before and after reaction were characterized by means of temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, scanning electron microscopy-energy dispersive spectroscopy, elemental analysis, and N2 physical adsorption. The results showed that the deactivated catalyst was not poisoned by impurities in the reaction system. The main causes for the deactivation of the Cu-based catalyst were the sintering and carbon deposition. The Cu composition in the catalyst did not change significantly during the reaction.

Key words: Cu-based catalyst, slurry-phase reactor, catalyst deactivation, methanol synthesis, stability