Synthesis and characterization of nanosized micro-mesoporous Zr–SiO2 via Ionic liquid templating

A series of micro-mesoporous Zr-SiO2 composites with nanoscale domains were prepared by using ionic liquid (IL) as a template at 373 K in only 3 h with one-step. The synthesized Zr-SiO2 materials were characterized by N2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, diffuse reflectance UV-Vis spectroscopy, thermogravimetric analysis and temperature program desorption technologies. The results show that the synthesized composite materials possess nanoparticle with a mean diameter of about 100 nm and a large surface area more than 1000 m2/g, and the hierarchically porous structure is preserved after removing template by calcination at high temperature and treating in boiling water for 72 h. The heteroatom of zirconium has been successfully incorporated into the structure framework and/or has been highly dispersed on the surface of materials. The prepared materials contain moderate to strong acid sites and the surface acid site concentration is 0.18-0.42 sites/nm2. The amount of strong acid sites increases with a decrease of Si/Zr ratio, which leads to increased temperature for removing IL templates.