Adsorption Equilibrium of Water Vapor on Mesoporous Materials

Abstract

Adsorption of water vapor on mesoporous materials such as MCM-41, MCM-48, KIT-1, SBA-1, and SBA-15, which have different pore sizes and shapes, was investigated by using a gravimetric system. In addition, adsorption of water vapor on KIT-1 mesoporous material was examined at 293.15 to 353.15 K. A hybrid isotherm model composed of a Henry isotherm and a Sips isotherm was applied to the analysis of water adsorption on mesopores including its surface adsorption and capillary condensation. The proposed isotherm nicely simulated measured adsorption data over the whole range at these experimental conditions. The capillary condensation of water vapor on mesoporous materials was highly dependent on temperature and pore sizes rather than on their pore shapes.