Solvent free isomerisation of longifolene with nano-crystalline sulphated zirconia

Nano-crystalline sulphated zirconia catalyst was synthesised using sol–gel technique in acidic, basic and neutral medium. The samples were characterised by X-ray diffraction, DRIFT spectroscopy, nitrogen adsorption–desorption and TG analysis. Bronsted acidity was measured by cyclohexanol dehydration model reaction. The samples were studied for single step, solvent free isomerisation of longifolene to iso-longifolene in a liquid phase batch reactor. The catalyst yielded >90% conversion and ∼100% selectivity for iso-longifolene.