Abstract: Nano-SiO2 with high activity and mesopores was prepared through sol-gel synthesis followed by low-temperature heat treatment and ball milling firstly in our experiments. TEM was performed to measure particle sizes. Nitrogen adsorption experiments were carried out to estimate specific surface area, porous distribution and porous ratio by BET and BJH methods. The content of Si-OH in SiO2 surface was calculated by analysis of the results of hydrogen-oxygen content mensuration (HOCM). As a result, appropriate heat treatment system and ball milling time are important to preparation for nano-SiO2 with high activity and mesopores, which are 5~50 nm particles, 5~6 nm average aperture, 85%~93% porous ratio, and 51%~55% Si-OH content in surface. Nano-SiO2 with that structure has high surface energy and activity. This process, which has simple facilities and operation rules, is a new way of preparation for nano-SiO2 with high activity and mesopores.

Key words: Heat treatment, Ball milling, Mesopores, Nano-SiO2