Desulfurization of a JP-5 light fraction (841 ppmw S) for on-board fuel cell applications was investigated by, pi-complexation adsorption with mesoporous SBA-15 and MCM-41 supported Cu2O. The effect of support and reduction temperature on the sulfur adsorption capacity was studied. The adsorbents were characterized with N-2 physical adsorption and CO chemisorption. The results showed that the mesoporous structures of the support remained intact during adsorbent preparation. It was found that significant breakthrough occurred at 10.0 mL/g for desulfurization of the JP-5 light fraction by Cu2O/MCM-41 reduced at 700 degrees C. The MCM-41 was more effective than SBA-15 as the support for Cu2O adsorbents in desulfurizaiton of jet fuel. The sulfur adsorption capacity increased with the reduction temperature. The spent Cu2O/MCM-41 was regenerated by heating in air and the regenerated adsorbent was tested for reuse. The results showed that similar to 100% of the sulfur capacity could be recovered.