A New Type of Super Hydrophilic SiO2 Aerogel for Use as a Potential NH3 Sorbent

A super hydrophilic SiO2 aerogel (SHSA) was prepared using the sol-gel method and CO2 supercritical drying technology, yielding a specific surface area of 680.08 m2/g and a total pore volume of 3.95 cm3/g. The hydrophilic property of the SHSA was investigated and showed a maximum water adsorption capacity (qm) of 7.79 ml/g. NH3 adsorption tests were conducted and were compared with the results for pure SiO2 aerogel (PSA) under non-water vapor and water vapor treating conditions. The effect of water vapor on SHSA was found to be larger than its effect on PSA. A physicalchemical adsorption process of NH3 appeared in the presence of water vapor on the SHSA surface, giving a maximum adsorption capacity (Qm) of 193.66 mg/g. The regenerability of SHSA was also investigated, and the loss percentage of Qm was found to be 22.28% over 10-cycle adsorption tests. The results indicate that SHSA is a promising candidate for use as an NH3 sorbent.