The strong endothermic reaction of hydrocarbon-fuel catalytic steam highlights its potential for use in high-temperature wall cooling. The cooling capacity and cracking-controlled coke of hydrocarbon fuel have been compared experimentally with and without a catalytic steam reforming reaction under supercritical pressure conditions, and the interaction effects between the thermal cracking and catalytic reforming reactions were analyzed. The results show that the hydrocarbon fuel catalytic steam reforming reaction can not only significantly improve the total heat sink and fuel conversion, but also reduce the coke deposition arising from the thermal cracking process. The chemical heat sink of the catalytic steam reforming reaction is higher than that of thermal cracking, especially in the high-temperature range. At temperatures below 500 degrees C, catalytic steam reforming provides a boost to the fuel compounds and turns them into small-molecular gas-phase products such as hydrogen and carbon monoxide. The catalytic reforming and thermal cracking reactions occur simultaneously at temperatures above 500 degrees C. The catalytic reforming reaction can lower the degree of thermal cracking and inhibit the polymerization of small molecules produced by cracking to aromatics, consequently resulting in less coke deposition. (C) 2014 Elsevier B.V. All rights reserved.