ABSTRACT
This work illustrates that supported heterogeneous Platinum Group Metal (PGM) catalysts are effective for the selective oxidation of alcohols to aldehydes and ketones using air as the oxidant. These reactions can be performed under mild reaction conditions (<70EC and <5 bar), giving high selectivities to the carbonyl when using organic solvents such as toluene and xylene. In general Pt/C catalysts have the highest activity for aliphatic alcohols, but Ru/C catalysts offer higher selectivities if the alcohol is prone to over oxidation to the carboxylic acid. However, for aromatic alcohols, although Pt/C and Ru/C catalysts are still effective, the best activities and selectivities are obtained with Pd,Pt,Bi/C mixed metal catalysts. In all cases the presence of base in the system is beneficial for both activity and selectivity, which is preferably a property of the catalyst rather than base added to the reaction mixture.
