Adsorption Behavior of the Primary, Secondary and Tertiary Alkyl, Allyl and Aryl Alcohols Over Nanoscale (1 0 0) Surface of gamma-Alumina

In this study, the adsorption behavior of the primary, secondary and tertiary alcohols over nanoscale (1 0 0) surface of defect spinel gamma-alumina was investigated with the aid of density functional theory (DFT) at BLYP/DNP level of calculation. The influence of different substituents including alkyl, cycloalkyl, allyl and aryl were analyzed for free and adsorbed alcohols to shed light the adsorption selectivity of these compounds over gamma-alumina surface. These results indicate that more branches at alpha position of alcohol favor the adsorption, while a decrease in adsorption energy is achieved for the alcohols containing the substituents at the beta position. The tertiary alcohols are adsorbed over the surface stronger than secondary and primary alcohols. Alcohols with larger alkyl chains have greater adsorption energies. Also the aryl alcohols are adsorbed over the surface better than the alkyl and allyl moieties.