Synthesis of alumina–carbon xerogel nanocomposites and their use as catalyst support

Abstract

Alumina–carbon xerogel (ACX) nanocomposites have been synthesised by an easy one-pot sol–gel process followed by pyrolysis at high temperature. Resorcinol formaldehyde aqueous gels and a peptised alumina sol were used as the carbon and alumina precursors respectively. N₂ adsorption measurements, X-ray diffraction and transmission electron microscopy revealed that the pore size distributions of the ACX could change from microporosity to mesoporosity with an increase in the alumina content from 5 to 20 wt-%. The walls of the ACX nanocomposite were composed of continuous carbon and γ-alumina. The catalytic hydrogenation of toluene results showed that the ACX supported Pt catalyst not only exhibited better selectivity in the hydrogenation of toluene to methylcyclohexane, but also behaved much stably than its single component counterparts, carbon xerogel or Al₂O₃ supported Pt catalysts, demonstrating the superiority of the ACX nanocomposite.

Keywords:

• Nanocomposite
• Carbon xerogel
• Alumina
• Toluene
• Hydrogenation

Acknowledgements

Financial supports by the foundation of Liaoning Province Educational Committee (grant no. 2008368) and Doctoral Program Foundation of Liaoning Province (grant no. 20091047) are gratefully acknowledged.