Selective oxidation of light alkanes under mild conditions (T-R 80-120 degreesC; P-R, 140 kPa) is attained in a multifunctional three phase catalytic membrane reactor (3PCMR), The functionalisation of C-1-C-3 alkanes to the corresponding oxygenates on superacid catalytic membranes mediated by Fe2+/H2O2 Fenton system is achieved. Among the various superacid catalytic agents, Nafion-based ones revealed the best performance, The features of the 3PCMR in enabling simultaneous reaction and product separation are presented. The influence of the operating conditions (T-R, [H2O2], [Fe2+] or [Fe3+]) on the catalyst activity is outlined. A general reaction pathway accounting for the activation of the C-H bond of the alkane molecule on the superacid sites and the subsequent reaction of the activated alkane with primary reactive intermediates, generated from the Fe2+/H2O2 system, is proposed.