A series of alumina supported Pd-ZnO catalysts were synthesized and studied for methanol steam reforming. Pd loading and Pd/Zn ratio were optimized to improve catalyst activities. Among all the catalysts studied, the catalyst with a I'd loading of 8.9 wt % and a Pd/Zn molar ratio of 0.38 exhibited the highest methanol conversion and the lowest CO selectivity. The significantly improved Pd-ZnO/Al2O3 catalyst activity was one of the main factors improving the efficiency of a microscale fuel processor from 9 % to 15 %.