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A hydrogen generator that generates hydrogen gas from the aqueous solution of sodium borohydride is developed.The performance testing of the hydrogen generator using a cobalt-phosphorous (Co-P) catalyst supported on a porous nickel foam is discussed.The microstructures and catalytic activities of the electroless-deposited Co-P catalysts are analyzed as a function of the electroless deposition conditions such as the pH and temperatures of heat treatment.The catalytic activity of the supported Co-P catalyst depends largely on the bath pH and calcinations conditions.For optimization of the hydrogen generator,hydrogen generation rate was measured as a function of NaBH4 concentration,NaOH concentration and flow rate of NaBH4 solution.When the NaBH4 concentration in aqueous solution (< 25 wt.%) is increased,the hydrogen generation rate linearly increases,but too high NaBH4 concentration (> 25 wt.%) causes clogging of the reactor because of increased solution viscosity.The hydrogen generation rate is also enhanced when the flow rate of the solution is increased.The response of hydrogen generation is improved by pumping liquid catalyst into the reactor before starting feeding the NaBH4 solution.The hydrogen generator successfully provided a stable hydrogen generation rate of 0.5 to 2 L/min.The hydrogen generator is used to supply hydrogen to a PEMFCs stack,and about 100 W power is produced at a constant loading of 6.5 A.