Deactivation of Bifunctional Mixed Catalyst for Dimethyl Ether Synthesis in Slurry Reactor

The stability of bifunctional mixed catalyst for dimethyl ether synthesis from synthesis gas in slurry reactor was investigated.The deactivation of mixed catalyst was found.Results of experiments show that water vapour affects the stability of mixed catalyst.The mixed catalysts before and after reaction were studied by NH_3-temperature programmed desorption(TPD),X-ray diffractometry(XRD) and X-ray photoelectron spectroscopy(XPS).TPD results show that acidity of bifunctional catalyst is not changed.XRD and XPS results show the valence state of Cu is maintained after reaction,but Cu grain of catalyst after reaction is bigger than that of before reaction.Main reasons of mixed bifunctional catalyst for dimethyl ether synthesis are the grain growth of Cu and the loss of Cu,which resulted in the decrease of both active site and active surface.