A FT-IR study of the adsorption of indole, carbazole, benzothiophene, dibenzothiophene and 4,6-dibenzothiophene over solid adsorbents and catalysts Original Research Article

The adsorption of benzothiophene (BT), dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (DMDBT), dibenzofuran (DBF), indole (IND) and carbazole (CARB) on alumina, zirconia and magnesia has been studied by IR spectroscopy. The main adsorption process is due to adsorption on Lewis sites or on acid–base pairs. On alumina the adsorption is strongest, desorption being not obtained above 723 K. BT also undergoes a transformation with likely the heteroaromatic ring opening. Adsorption of 4,6-DBT is definitely limited in extent likely due to steric hindrance. The N-containing compounds IND and CARB are adsorbed dissociatively with breaking of the NH bond.