TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The catalyst comprises a coating (7) of a material which permits fuel and oxidant to reach the catalyst and allows products to leave, or a material which is selectively permeable to the fuel and the oxidizing gas. The selectively permeable material includes rubbers, silicone rubbers, polymers, ionic polymers, Nafion (RTM; perfluorosulfonic acid), sulfonated butyl rubber,and/or polystyrene. The porous substrate is polybenzoxazoles (PBOs), polybenzimidazoles (PBIs), para-aramids, polyimides, silicon carbide, alumina, carbon, fiber glass, zirconia and/or quartz.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The catalysts enable catalytic combustion of fuels, and are preferably highly dispersed platinum, palladium, nickel, ruthenium, iron, molybdenum, tungsten and/or tin. The porous substrate is polybenzoxazoles (PBOs), polybenzimidazoles (PBIs), para-aramids, polyimides, silicon carbide, alumina, carbon, fiber glass, zirconia and/or quartz.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The fuel is a compound comprising hydrogen, preferably methanol, formaldehyde, formic acid, 1,3,5-trioxane, di-methyl-ether, or their combinations.    TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Device: The device further comprises enhancement of a performance of the catalyst with the catalyst coating, which includes enhancing properties including surface protection, adhesion, filtration of external contaminates, varying affinity for fuel, varying affinity for oxidizing gas, diffusion rate limits of reactants to a surface of the catalyst, temperature dependency, regulation of diffusion rates of reactants to the surface of the catalyst, acidifying the surface, alkalizing the surface, or their combinations. It further comprises an upper temperature limit setting on a thermal output caused by boiling the fuel. The fuel is removed from a catalytic reaction area by boiling.The device further includes valves, flow restrictions, or pressure relief for regulating a boiling temperature of the fuel. It further comprises optimal conditions in the device for catalytic combustion of vented gases from the selective membrane container; regulation of fuel delivery rate with self pressurization of the fuel; electrical temperature responsive devices for controlling fuel flow, heat exchangers for transferring heat from the device to the fuel; heat exchangers for heating air going to the catalyst; heat pipes for transferring heat from the device, regulating temperatures in the device, and transferring heat to fluids and solids; fuel additives for regulating temperatures and heat production rates; mixtures of fuels; thermoelectric devices for extracting electrical energy; a delivery system for delivering electrical energy to batteries, motors, and electronic devices; and water produced from fuel combustion.The selectively permeable membrane regulates delivery of oxidant to the catalyst. The device further comprises a wick for distributing liquid fuel over a surface of selectively permeable membrane. The membrane uses the selective permeability to aspirate, circulate, or prevent motion of the fuel. It changes diffusion rates with changes in temperature.The device further comprises fans or pumps for regulating delivery of fuel or oxidant to an area of the catalyst; an electric heater for initiating optimal conditions to operate the device; an ignition system for igniting fuels and air and for heating the catalyst; a proton-conducting material for supporting the catalyst, at least two electrodes on either side of the proton-conducting material, and a power source connected to the electrodes for providing a voltage; influencing catalytic combustion rates by applying voltage across the proton-conducting material; a receiver for receiving the device; a mechanism for pumping fuel towards an area of the catalyst; a fuel ampoule having fuel-permeable walls for holding and releasing the fuel; and an impermeable material for holding the ampoule for preventing leakage of the fuel prior to use.