Microwave-assisted polycondensation for screening of organically-modified TiO2/SiO2 catalysts

Abstract Development of efficient and environmental-friendly solid catalysts is an important target for polyester production. Herein, we report a novel screening strategy based on microwave-assisted polycondensation and its application for exploring organically-modified TiO2/SiO2 catalysts with varied chemical composition and organic functionality. Modification of TiO2/SiO2 catalysts with specific organic groups resulted in superior polycondensation performance at a reduced amount of titanium. Among these, phenylethyl modification was found to be most promising, which exhibited at least 9 and 19 times higher activity than industrial TiO2/SiO2 and Sb2O3 catalysts. The phenylethyl modification during coprecipitation led to smaller catalyst particles with improved hydrophobicity, and the dilution of surface titanium sites by silicon atoms for enhanced Lewis acidity. Synergistic combination of these positive consequences realized the high activity of the developed catalyst, particularly at low temperature.