The aromatisation of propane has been studied using Ga2O3, H-ZSM-5 and physical mixtures of Ga2O3/H-ZSM-5 as catalysts. Experiments using co-fed reactants of H-2, O-2 and NO are described, together with the use of 2-chloro-propane as a model reactant. The results are discussed in terms of a mechanism for the formation of the initial product propene in which propane is activated at the interface between the gallium oxide and the zeolite. The system is therefore an example of contact synergy and furthermore experiments are described that provide evidence for the reversible formation for the active site for this catalyst system.