NOVELTY - An integrated hydrogen production and purification reactor comprises a hydrogen-selective, hydrogen-permeable gas separation module comprising a porous substrate, an intermediate layer having particles and a binder metal distributed throughout the intermediate layer, and a hydrogen-selective membrane that overlies the intermediate layer.    USE - For high temperature production and separation of product gases, and for producing a high purity gaseous product, e.g. hydrogen for fuel cells.    ADVANTAGE - The invention is durable for a high temperature operation by preventing intermetallic diffusion while being thin enough to provide high fluxes of hydrogen gas. It provides a more uniform heating and has more control over temperatures at various points to avoid hot spots. It has minimal production of NOx within the integrated reactor, and provides improvements in heat exchange efficiency and load-following capabilities to drive the steam reforming reaction.    DETAILED DESCRIPTION - An integrated hydrogen production and purification reactor comprises a reaction chamber comprising a catalyst bed to produce reaction products comprising hydrogen gas from a hydrogen-producing feedstock; and at least one hydrogen-selective, hydrogen-permeable gas separation module adapted to receive the reaction products from the catalyst bed and to separate the reaction products into a product stream comprising hydrogen and a byproduct stream. The gas separation module comprises a porous substrate (110), an intermediate layer (112) at the porous substrate that comprises particles and a binder metal distributed throughout the intermediate layer, and a hydrogen-selective membrane (114) that overlies the intermediate layer. INDEPENDENT CLAIMS are also included for:    (A) a steam reforming process for the production of hydrogen, comprising reacting steam with a hydrogen-producing feedstock at 200-700degreesC and 0.1-20 MPa in a steam reforming reaction chamber containing a reforming catalyst to produce a mixture of primarily hydrogen and carbon dioxide, with a lesser amount of carbon monoxide; and separating hydrogen from the mixture produced by the reforming reaction with a hydrogen-selective, hydrogen-permeable gas separation module; and    (B) an integrated steam reforming reactor-hydrogen fuel cell comprising the inventive reactor where the product stream containing hydrogen is delivered from the reactor to an anode compartment of a hydrogen fuel cell and the byproduct stream from the reactor is delivered to a cathode compartment of the hydrogen fuel cell.    DESCRIPTION OF DRAWING(S) - The figure shows a partial cross-section of a composite gas separation module.    Porous substrate (110)    Intermediate layer (112)    Membrane (114)    Pores (116)