AN AUTOMATED, HIGH-PRECISION UNIT FOR LOW-PRESSURE PHYSISORPTION

A physisorption apparatus with very high sensitivity has been constructed. It is capable of accurately measuring adsorption and desorption isotherms of gases on solids in the pressure range of 10(-5)-1000 Torr. This is particularly useful for investigating argon sorption on catalysts and catalyst supports, e.g., FCC, reforming and hydroprocessing catalysts; zeolites; and pillared layered materials. The isotherms contain information about micropore and mesopore size distribution, BET surface area, etc. The operation of the unit and the analysis of isotherm data are both fully automated. Details of the equipment and the software are described.