Ruthenium containing hydrotalcite as a heterogeneous catalyst for hydrogenation of benzene to cyclohexane

Abstract Ruthenium containing hydrotalcite (Ru-HT) was synthesized by partial substitution of Mg 2+ or Al 3+ cations by ruthenium metal in octahedral layers of hydrotalcite and used as a catalyst for hydrogenation of benzene to cyclohexane. Effect of catalyst amount, reaction temperature, partial pressure of hydrogen and volume of solvent on conversion of benzene was studied in detail. Higher conversion of benzene in lower reaction time was observed in lower volume of solvent. Complete conversion of benzene with 100% selectivity of cyclohexane was observed at 120 °C reaction temperature and 60 atm partial pressure of H 2 in 2 h reaction time. Presence of moisture in the reaction mixture showed negligible effect on catalytic activity of Ru-HT, however, activity decreased significantly on increasing the sulfur concentration. Catalyst was recycled upto four times without significant loss in its activity. No conversion of benzene was observed in case of pristine hydrotalcite (without ruthenium) as a catalyst.