Analysis of silica surface heterogeneity using butane and butene adsorption data

Adsorption isotherms for butane and butene measured on silica samples at different temperatures are used as a data base for describing the chemical and physical changes in the systems. The stable numerical method for solving the adsorption integral equation (SAIEUS) is used to deconvolute adsorption data. The effect of lateral interactions between adsorbed molecules on the results obtained is underlined. The adsorption properties of the initial and heat-treated silica samples are discussed in terms of their butane and butene adsorption energy distributions. The analysis of the results obtained reveals the complex nature of the silica surface due to its microporosity and the presence of surface hydroxyl groups. (C) 1997 Academic Press.