TEMPERATURE-PROGRAMMED DESORPTION OF NORMAL-ALKANES FROM SILICALITE-1

Temperature programmed desorption (TPD) of n-alkanes, ranging from n-h exane to n-hexadecane, from silicalite-1, was conducted between ambien t temperature and 500 degrees C on a thermogravimetric (TG) balance at heating rates of 3, 6 and 10 C degrees min(-1). The derivative TG cur ves all showed two distinctive peaks. An inflection point in the TG pr ofiles was found at about four molecules per unit cell in all cases ex cept hexadecane, which occurred at 1.92 molecules per unit cell. The s aturation adsorption volumes of all sorbates was close to the theoreti cal value of similar to 0.19 mi g(-1). (C) 1997 Elsevier Science B.V.