Perfluorinated resinsulphonic acid (Nafion-H (R)) was found to be highly efficient, environmentally friendly, recyclable heterogeneous catalyst for the oxidation of sulphides to sulphones, tertiary amines to N-oxides, secondary alcohols to esters/lactones and aldehydes to methyl esters in excellent yields under mild reaction conditions using 30% hydrogen peroxide as an oxidant. Alkyl sulphides in general were found to be more reactive than aryl sulphides. Similarly, aliphatic tertiary amines and pyridines substituted with electron donating groups were found to be more reactive. Among the various secondary alcohols and aldehydes studied, alicyclic alcohols and substituted benzaldehydes were found to be more reactive. Acetonitrile and 1,2-dichloroethane were found to be the most suitable solvents for these transformations. (c) 2005 Elsevier B.V. All rights reserved.