Constant hydrogen generation via a hydrogen generator is evaluated from the methanolysis of sodium borohydride (NaBH4) using Co/Al2O3 and MnOx/Al2O3 catalysts. Chemical borohydrides coupled with catalysts can be used for compact storage and to create efficient generation systems. Thus, we first report the catalytic activity of MnOx/Al2O3, which is synthesized using the simple wet-impregnation method, for the methanolysis reaction. The results indicate that both catalysts can effectively accelerate the methanolysis reaction and provide constant hydrogen generation rates. Thus, we integrate this hydrogen generation system into a proton exchange membrane fuel cell stack (PEMFC) to determine whether it can be used as a portable power supply. As a result, this fuel cell system operates at 40 W for 1 hr using the hydrogen source supplied from the catalytic methanolysis reaction.