HEAT OF CHEMISORPTION OF 1-PROPANOL ON ALPHA-AL2O3 AT 25-200-DEGREES-C - A MICROCALORIMETRIC STUDY

We have studied by means of differential microcalorimetry the adsorpti on process of 1-propanol on alpha-Al2O3 at the temperatures of 25, 50, 100, 150 and 200-degrees-C, respectively. Both amounts of adsorbed al cohol and heats released decrease as the temperature of adsorption inc reases. At very low coverage, the high value of differential heat show s a strong irreversible chemisorption on active sites (Lewis acid site s) (qdiff > 200 kJ.mol-1). Moreover, we carried out some thermokinetic investigations on heat emission peaks at different coverage degree (d ifferent equilibrium pressure of 1-propanol vapour as a function of ti me) and at different temperatures of adsorption, at same coverage.