Adding catalysts to jet fuels has advantages such as accelerated combustion and increased heat sink capacity. The multitude of parameters determining catalyst performance forms a considerable challenge, such as optimal particle composition and size which primarily determine reaction rates and energetics, plus sintering resistance. Prerequisites for such studies are 1) catalysts with well defined size/composition and 2) characterization of the catalyst at work. In this study, cyclohexane is used as fuel surrogate and its dehydrogenation on Pt- and Co-based catalysts is monitored by temperature programmed reaction combined with in situ X-ray scattering and absorption. The results shows that efficient dehydrogenation of cyclohexane can be performed on subnanometer and nanometer size catalysts, moreover at low temperatures. Catalytic performance can be tuned by varying composition and functionalization of the support material, the size and doping of the nanocatalyst. DFT studies are used to help understand the structures and reaction pathways.