We investigate surfactant systems for catalytic gas/liquid reactions, namely the hydrogenation of dimethylitaconate (DMI) and the hydroformylation of the long-chain olefin 1-dodecene. We show that surfactant selection is crucial to obtain a high activity and selectivity. Choosing an appropriate surfactant results in comparable selectivity's as in conventional organic solvents, but usually at lower activities. For microemulsion systems, the activity is strongly influenced by the phase behavior. For both reactions we present a concept of catalyst recycling based on the specific properties of the surfactant system. The efficiency for catalyst recycling is >97% with minor loss in activity. (C) 2014 Elsevier B.V. All rights reserved.