Deactivation phenomena of MoO3/SiO2 and TiO2/SiO2 during transesterification between dimethyl carbonate and phenol

The catalytic stability of MoO3/SiO2 and TiO2/SiO2, which have been reported to be active for transesterification between dimethyl carbonate and phenol, was examined in a batch reactor for the same reaction. X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and the temperature programmed oxidation (TPO) were conducted to characterize the catalysts. The gradual decrease in the activity was observed over both catalysts with increasing the number of a batch reaction. The strong adsorption of reactants was observed from the temperature programmed oxidation experiment. The deactivated MoO3/SiO2 can be regenerated after oxidation in air at 823 K. However, the deactivated TiO2/SiO2 can be only partially regenerated even after oxidation in air at 973 K. Some of the Mo species in MoO3/SiO2 were leached out during a reaction. This dissolved homogeneous Mo species appeared to take part in this reaction.

The catalytic stability of MoO3/SiO2 and TiO2/SiO2 was examined for transesterification between dimethyl carbonate and phenol. The gradual decrease in the activity was observed over both catalysts due to the strong adsorption of reactants. Some of the Mo species in MoO3/SiO2, leached out during a reaction, appeared to take part in this reaction.Figure optionsDownload as PowerPoint slide