Surface and catalytic properties of acid metal–carbons prepared by the sol–gel method

The sol–gel method has been applied for the synthesis of a series of acid metal–carbon xerogels (withM = V, Cr,Mo and Ni) by polymerisation of resorcinol with formaldehyde in the presence of metallic precursors. A blank sample was also prepared without any metal addition. The xerogels were heated in nitrogen at 1000 8C to obtain the pyrolysed products. The samples were characterised by different techniques such as thermal-mass spectrometry analysis, gas physisorption, and mercury porosimetry. In addition, the acid character of the pyrolysed products was tested by the Claisen–Schmidt condensation between benzaldehyde and acetophenone for the formation of chalcones