Cooling technology exploiting the endothermic reaction of fuel has been developed to prevent structural deformation in engines due to air friction and overheating during supersonic flight. Endothermic fuels are liquid hydrocarbon fuels that can absorb heat through endothermic reactions. The initial heat sink capacity of conventional pellet type catalysts for the endothermic reaction cannot be maintained, leading to more rapid deactivation due to coke formation. To maintain the heat sink performance of decomposition catalysts, HZSM-5 catalyst washcoated on metal foam(HZSM-5/metal foam) was used herein. The reactions were carried out in a batch reactor at 673 K at a pressure of 50 bar using methylcyclohexane (MCH) and n-dodecane as reactants. The total MCH conversion achieved with the pellets and HZSM-5/metal foam was same at 93 %. In the case of ndodecane, the total conversion achieved with the HZSM-5/metal foam (91 %) was superior to that achieved with the pellets (69 %).