NOVELTY - Production of hydrogen and carbon monoxide comprises introducing a hydrocarbon fuel upstream from a catalytic zone comprising a reforming catalyst (108) and an oxidation catalyst, into an oxygen containing gas stream to produce a rich mixture, where a portion of the hydrocarbon fuel in the rich mixture is oxidized on the oxidation catalyst and all of the remaining hydrocarbon fuel is reformed on the reforming catalyst, and gas stream is periodically converted to a lean mixture for a short period to maintain catalyst activity.    USE - The process is for production of H2 and CO. It is useful for producing H2 containing gas stream (claimed). Hydrogen is used in a fuel cell e.g. proton exchange membrane, phosphoric acid fuel cell, or solid electrolyte fuel cell for use as a portable power source, e.g. for battlefield use, in a vehicle, for an auxiliary power unit for generation of backup power, or for a communication switching station. It is also used in other device or process requiring H2.    ADVANTAGE - The process provides a high density and portable fuel processing system capable of generating proton exchange membrane quality hydrogen from common liquid heavy hydrocarbon fuels such as diesel utilizing methods for production of hydrogen. It enables hydrogen to be produced at a low steam-to-carbon ratio. Since the reactants are in liquid phase, no gas compression is required to operate the reformer at elevated pressures. The combined features of the system result in a compact, portable system suitable for a range of portable power applications, and in a low mass system conducive for portable power uses.    DETAILED DESCRIPTION - Production of hydrogen (H2) and carbon monoxide (CO) comprises introducing a hydrocarbon fuel into an oxygen (O2) containing gas stream to produce a rich mixture, where fuel is introduced upstream from a catalytic zone comprising a reforming catalyst and an oxidation catalyst, where introduced fuel flows through the catalytic zone, a portion of the hydrocarbon fuel in the rich mixture is oxidized on the oxidation catalyst and all of the remaining hydrocarbon fuel is reformed on the reforming catalyst, producing H2 and CO, and where gas stream is periodically converted to a lean mixture for a short period to maintain catalyst activity by reducing the concentration of introduced hydrocarbon fuel or increasing the concentration of 02 in the gas stream.    INDEPENDENT CLAIMS are also included for:    (1) a H2 containing gas stream; and    (2) a system for producing H2 and CO, comprising an inlet, a catalytic zone comprising a reforming catalyst and an oxidation catalyst, an outlet, an O2 containing gas stream flowing from the inlet to the outlet through the catalytic zone, and a reservoir comprising a hydrocarbon fuel, where reservoir is in fluid communication with the gas stream upstream from the catalytic zone and downstream from the inlet, where the system is configured to introduce hydrocarbon fuel from the reservoir upstream from the catalytic zone to form a rich mixture in the gas stream flowing from the inlet to the outlet, and where rich mixture flows through the catalytic zone, the system is configured to introduce an amount of hydrocarbon fuel such that as the rich mixture flows through the catalytic zone, a portion of the introduced hydrocarbon fuel is oxidized on the oxidation catalyst and all of the remaining hydrocarbon fuel is reformed on the reforming catalyst, producing H2 and CO, and where system is configured to periodically convert the gas stream to a lean mixture for a short period to maintain catalyst activity by reducing the concentration of introduced hydrocarbon fuel or increasing the concentration of O2 in the gas stream.    DESCRIPTION OF DRAWING(S) - The figure schematically depicts a fuel processor for reforming of hydrocarbon fuel to hydrogen, using hydrogen peroxide as a reactant.    Heat exchanger (100)    Heat exchange surfaces (104, 105)    Reforming catalyst (108)    Selective diffusion membrane (109)