NOVELTY - A catalytic reactor comprises heat exchanging element that transfers heat from the exothermic reaction to preheat the fuel solution, liquid diffusing element that distributes the flow of fuel solution to enhance its contact with first catalytic material, a second catalytic material that generates hydrogen upon contact with the fuel solution, and a membrane operative at pressures of greater than or equal to 50 psig that separates the hydrogen from the fuel solution.    USE - For use in hydrogen generation from a fuel solution.    ADVANTAGE - The reactor has improved operational performance. It includes fuel-diffusing element that enhances the contact of the fuel solution with the catalyst to increase the rate of hydrogen generation. The different catalytic material enhances certain operational characteristics, such as start-up response time. The membrane is capable of withstanding pressures of greater than or equal to 50 psig, thus enhancing the operation of the reactor by providing separation of the generated hydrogen from the liquid fuel within the catalytic reactor, and eliminating or reducing the size of downstream gas/liquid separation elements.    DETAILED DESCRIPTION - A catalytic reactor (116) comprises an inlet for receiving a fuel solution and a first catalytic material that generates hydrogen upon contact with the fuel solution via an exothermic reaction. It further comprises element such as heat exchanging element that transfers heat from the exothermic reaction to preheat the fuel solution prior to its contact with the first catalytic material, liquid diffusing element which distributes the flow of the fuel solution to enhance its contact with the first catalytic material, a second catalytic material that generates hydrogen upon contact with the fuel solution, and a membrane operative at pressures of greater than or equal to 50 psig that separates the hydrogen from the fuel solution. The second catalytic material is disposed in the catalytic reactor to contact the fuel solution. It has hydrogen generation characteristics that are different from those of the first catalytic material.    INDEPENDENT CLAIMS are also included for:    (A) a hydrogen gas generation system, comprising fuel storage chamber containing an aqueous solution of chemical hydride, inventive catalytic reactor, conduit for conveying the aqueous solution from the fuel storage chamber to the reactor, and outlet conduit to convey a liquid byproduct of the exothermic reaction to a storage chamber; and    (B) a method of generating hydrogen from a fuel solution, comprising utilizing a catalytic reactor having a first catalytic material that generates hydrogen upon contact with the fuel solution via an exothermic reaction.    DESCRIPTION OF DRAWING(S) - The drawing shows a cut-away view of a catalyst reactor integrated with a heat exchange coil surrounding a packed catalyst bed in the invention.    Fuel line (112)    Reactor (116)    Catalyst bed (118)    Conduit line (136)    Distributor (210)