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- Author or Editor: F. Oliveri x
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Heat of chemisorption of 1-propanol on α-Al2O3 at 25–200°C
A microcalorimetric study
Abstract
We have studied by means of differential microcalorimetry the adsorption process of 1-propanol on α-Al2O3 at the temperatures of 25, 50, 100, 150 and 200°C, respectively. Both amounts of adsorbed alcohol and heats released decrease as the temperature of adsorption increases. At very low coverage, the high value of differential heat shows a strong irreversible chemisorption on active sites (Lewis acid sites) (qdiff>200 kJ·mol−1). Moreover, we carried out some thermokinetic investigations on heat emission peaks at different coverage degree (different equilibrium pressure of 1-propanol vapour as a function of time) and at different temperatures of adsorption, at same coverage.
Abstract
The geochemical behavior of REE has been tested in the Umbro-Marchean (Italy) pelagic sequences of Cretaceous-Paleocene age. REE were determined by INAA in a number of limestone, marl and clay samples. Both chondrite and shale normalized patterns are discussed: the observed REE amounts and distributions are mainly attributed to highly complex diagenetic processes.
