MXPA01002845A - Electrocatalytic method and device for removing carbon monoxide from hydrogen-rich gas - Google Patents

Abstract

A method and apparatus removes carbon monoxide from hydrogen rich fuel by means of a catalytic material that preferentially adsorbs carbon monoxide. The catalytic material is regenerated by an oxidizing agent that reacts with the carbon monoxide absorbed by the catalytic material.The reaction is initiated by an electrical current is generated either galvanically or electrolytically through the catalytic material. The carbon monoxide free gas thus produced may then be passed into a fuel cell in order to provide D.C. power.

Description

METHOD AND ELECTROCATALYTIC DEVICE FOR ELIMINATING CARBON MONOXIDE FROM A RICH GAS IN HYDROGEN REFERENCE TO RELATED APPLICATIONS This application is based on U.S. Provisional Patent Application No. 60 / 100,990, filed on September 18, 1998.

BACKGROUND OF THE INVENTION This invention relates to the removal of carbon monoxide from a reformed hydrocarbon fuel. More specifically, it relates to the apparatus and method that uses a catalytic material to adsorb carbon monoxide and an electric current to initiate a chemical reaction between an oxidizing agent and carbon monoxide that has been adsorbed by the catalytic material, thereby regenerating the material. The internal combustion engines found in most cars and trucks burn a hydrocarbon fuel such as diesel or gasoline to drive the pistons or rotating mechanisms by force of expansion gas. Many of the electric power plants burn fossil fuel to produce electricity through combustion turbines.

These processes suffer from some limitations. These are inefficient due to the intrinsic limit of the thermodynamic principles involved. The combustion of fossil fuel is sometimes incomplete and produces harmful byproducts such as carbon monoxide, nitrogen oxides and some hydrocarbons in the emissions, which has given rise to environmental pollution. In addition, there is growing concern that we are rapidly depleting non-renewable energy resources on this planet. This, in turn, has led to concerns about reducing energy consumption by increasing the efficiency and utilization of renewable energy resources. The fuel cells convert the chemical energy contained in the fuel directly to electrical energy through electrochemical reaction. Because they do not operate on the principle of gas expansion through combustion, they do not have the same limitations of the thermodynamic efficiency commonly found in automobile engines and steam turbines. Therefore, it is possible that fuel cells obtain a level of efficiency much greater than that observed in most traditional industrial processes. What's more, fuel cells make it possible for fuel processors to use renewable forms of energy such as methanol and ethanol, thereby conserving the planet's limited fossil fuel resources. In addition, due to the operating environment of a fuel cell and fuel cell processor, the emissions of hydrocarbons, nitrogen oxide and carbon monoxide are insignificant, approaching zero emission states. Although there are some types of fuel cells existing in practice, this invention is mainly directed to the applications in polymeric electrolyte fuel cells (PEFC) which are also known as proton exchange membrane fuel cells (PEMFC). A very efficient PEFC uses pure hydrogen for fuel and oxygen for an oxidant. However, it has traditionally been difficult to handle pure and relatively expensive hydrogen storage and distribution. Consequently, attempts have been made to use mixtures of hydrogen-rich gases obtained from the reformation of some hydrocarbon fuels. To obtain a convenient and safe source of hydrogen for the fuel cells, it is expected that the reformation of hydrocarbon-based fuels, such as gasoline and methanol, will be used. However, these fuels usually contain nitrogen, carbon dioxide and low concentrations of carbon monoxide in the range of hundreds of ppm to a few hundred. Although the presence of carbon dioxide generally has little effect on the efficient operation of a fuel celleven relatively low concentrations of carbon monoxide can degrade the functioning of the fuel cell. The degradation results from adsorbing carbon monoxide chemically on the active sites in the fuel cell electrode. Thus, the removal of carbon monoxide from fuel has become an important aspect in the advancement of PEFC technology. Previous attempts to remove carbon monoxide from a gas mixture include a pressure swing absorption method described in Nishida et al., U.S. Patent No. 4,743,276. They describe a method for selectively absorbing carbon monoxide by means of Cu (I) located on a zeolite support, including the step of compressing adiabatically a gaseous mixture in the pressure range of 0.5 kg / cm2 to 7 kg / cm2 . Golden et al., U.S. Patent No. 5,531,809 discloses an oscillating vacuum method as a variation of the oscillating pressure method described in Nishida. A solid absorbent is selected that physically absorbs carbon monoxide under pressure. When the pressure is reduced to the range of about 20 to 100 torr, the carbon monoxide is released from the solid absorbent. By cyclically repeating this process, carbon monoxide can be removed from a gas. However, there are multiple limitations to applying the pressure oscillating adsorption method to fuel cell applications. First of all, to carry out this process, voluminous and expensive pressure resistant tanks are required, as well as pressure and vacuum pump apparatuses. The parasitic weight and volume of these devices can make it extremely difficult to apply the oscillating pressure absorption method for transportation applications such as a fuel cell power plant for a car. A second disadvantage of this method is the significant energy expenditure necessary for the cycles of the pressurization and depressurization steps. This additional energy consumption will lead to the reduction of the overall efficiency of the fuel cell system. Yet another disadvantage of this process is that the toxic carbon monoxide released from the desorption has to be converted into carbon dioxide with additional steps and process equipment.

Another process of the prior art has been known as preferential catalytic oxidation (PROX) of carbon monoxide which was documented in U.S. Patent No. 5,271,916 by Vanderborgh et al. In the PROX process, a small amount of pure oxygen or air is mixed in the reformed fuel before it is introduced into a single-stage or multi-stage catalytic reactor. The catalyst in the reactor, which generally contains dispersed precious metals such as platinum, ruthenium, iridium, etc., preferably reacts with carbon monoxide and oxygen to convert them to carbon dioxide. However, due to limited selectivity, an amount of oxygen rather than stoichiometric is needed to reduce carbon monoxide to an acceptable concentration. Also, excess oxygen will oxidize the oxygen in the reformed fuel. Even with the PROX process, the concentration of CO in the reformed stream is usually still significantly higher than the desired concentration for the operation of the sustainable PEFC. In addition, the carbon dioxide in the reformate can be converted to carbon monoxide through an inverted water-gas displacement reaction within the fuel cell. In addition to removing the residual carbon monoxide escaping from the pretreatment or forming from the inverted water-gas displacement reaction inside the fuel cell, a direct oxygen injection was developed for the fuel cell method, by example, Gottesfeld, U.S. Patent No. 4,910,099 describe a method for injecting an oxygen or air stream into the hydrogen fuel to oxidize carbon monoxide. Pow et al., U.S. Patent No. 5,316,747 describe a similar means for removing carbon monoxide by directly introducing pure oxygen or an oxygen containing gas along the last portion of a reaction chamber in an isothermal reactor in the presence of a catalyst that promotes the oxidation of carbon monoxide. Wiikinson et al,. US Patent No. 5,482,680 describes the removal of carbon monoxide from a hydrogen fuel for a fuel cell by introducing a stream of hydrogen-rich reactants into a passage having an inlet, an outlet and a catalyst that improves the oxidation of the carbon; introducing a first gas stream containing oxygen into the oxygen-rich reactant stream through a first inlet along a passage; thereby oxidizing some of the carbon monoxide within the stream of reactants; and introducing a second gas containing oxygen at a subsequent point, further oxidizing the remaining carbon monoxide. Wiikinson et al., U.S. Patent No. 5,432,021 likewise oxidizes carbon monoxide to carbon dioxide by means of an oxygen-containing gas, introduced into a stream of hydrogen-rich reactants in the presence of an unspecified catalyst. There are some important limitations for the PROX process and the oxygen injection process. One of these limitations is the parasite consumption of hydrogen. Due to the limited selectivity, the oxidant injected into the hydrogen-rich fuel is always greater than the stoichiometric amount necessary to oxidize carbon monoxide. Unreacted oxygen will consume hydrogen in the stream to, therefore, reduce fuel efficiency in general. Another important limitation of these methods is their poor tolerance towards the variation of the level of CO introduced in the reformed. To minimize parasitic hydrogen loss, the oxygen to CO ratio has to be maintained at a relatively low level in both methods. Furthermore, the CO input level tends to vary as a result of changing the energy output of the fuel cell and, thus, the performance of the reformed. It is difficult to constantly couple the CO input level with the oxygen level in a dynamic environment. In consecuense, the unreacted CO will exceed the tolerance level of the fuel cell, giving rise to a malfunction. Still another limitation of these two methods is the security aspect. The oxygen to hydrogen ratio in the mixture has to be strictly controlled below the explosion threshold. Another prior art process for removing carbon monoxide includes membrane separation, by means of which the hydrogen in the reformate can be separated by a metal membrane. For example, R.E. Buxbaum, U.S. Patent No. 5,215,729 describes a palladium-based metal membrane that provides selectivity for up to 100% hydrogen separation. Therefore, it could remove carbon monoxide and other components of the hydrogen that is the fuel for PEFC. Although it is highly selective, the process has some disadvantages. Since it uses precious metal as a membrane material, it is expensive. In addition, the reformed has to be pressurized to facilitate the separation process that gives rise to loss of parasitic energy and complexity in the equipment. Methanization is another prior art process for removing carbon monoxide through the catalytic reaction of carbon monoxide with hydrogen to form methane. An example of this method is provided by Fleming et al., U.S. Patent No. 3,884,838. Methane does not have a harmful impact and is considered non-reactive in the fuel cell. However, the methanation reaction requires hydrogen as a reactant and, therefore, increases parasite fuel consumption for the fuel cell. Moreover, under the condition of methanation, not only carbon monoxide but also carbon dioxide participates in the reactions. The reaction of carbon dioxide with hydrogen generates carbon monoxide through chemical equilibrium. Therefore, it is difficult to reduce the concentration of carbon monoxide to the desirable limit for PEFC operation. Due to the sensitive nature of fuel cells, it is vital that carbon monoxide removal reach 100% efficiency. In addition to the limitations of the process, such as cost, excess volume and weight, the complexity of the system and the high consumption of parasite hydrogen for the aforementioned methods, there is another common drawback, that is, the slow response during startup Cooling of the power plant by fuel cell. Most of these methods require the system to reach a certain temperature before it is operable, which usually represents an unwanted delay between start-up and normal operation. Therefore, there is a need for a method to remove carbon monoxide from a hydrocarbon reforming that is highly efficient, that shows better tolerance to oscillations in carbon monoxide concentration, that reduces parasite hydrogen consumption, which eliminate carbon monoxide ventilation to the atmosphere, which can operate simply and economically, and which can operate at the temperature and pressures of a fuel cell, as well as during start-up mode.

SUMMARY OF THE INVENTION In the present invention, a processor for electrocatalytic oxidation (ECO) to remove carbon monoxide from a hydrocarbon reformate consists of a cell containing a catalytic electrode material that preferably adsorbs and reacts with carbon monoxide. An oxidizing agent that reacts with carbon monoxide absorbed [sic] by the catalytic material, usually converting carbon monoxide to carbon dioxide, regenerates an adsorption capacity of this catalytic material. The electric cables located on the opposite sides of an electrode assembly with proton-permeable membrane form a circuit capable of discharging a current through the catalytic material, thereby activating the regeneration process. The circuit can be galvanic in nature, or be composed of a separate CD power supply. A system for the removal of carbon monoxide according to the present invention consists of a fuel processor that processes a hydrocarbon fuel containing carbon monoxide; a processor for the electrocatalytic oxidation downstream of the fuel processor that is capable of removing carbon monoxide from the fuel by means of a catalytic material that preferably adsorbs carbon monoxide; and an electrical circuit that produces an electrical current through the catalytic material, thereby converting carbon monoxide to carbon dioxide through electrocatalytic oxidation and regenerating the catalytic material. A method for removing the carbon monoxide from a hydrocarbon reforming according to this invention consists of the steps of: humidifying the reformate; moving the humidified reformate through a catalytic electrode material that preferably adsorbs carbon monoxide; and producing an electrical current through the catalytic material that triggers a reaction between the adsorbed water as well as the oxidizing species formed from the water during the electrochemical process with carbon monoxide, thereby converting carbon monoxide to carbon dioxide and regenerating the catalytic material. These and other features, aspects and advantages of the present invention will be better understood with reference to the following drawings, description and clauses.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 describes a block diagram of a method and apparatus for removing carbon monoxide from a fuel according to an embodiment of the present invention; Figure 2a depicts a membrane electrode (MEA) assembly of a processor for electrocatalytic oxidation (ECO) according to an embodiment of the present invention; Figure 2b depicts a bipolar plate that can be used on the anode and cathode sides of the MEA shown in Figure 2a; Figure 3 is a graph of the concentrations of carbon monoxide and carbon dioxide at the outlet of an ECO device against time according to a first galvanic mode of a method of the present invention, wherein carbon monoxide is present at approximately 1014 ppm at the inlet and the ECO processor uses platinum-ruthenium (Pt-Ru) as a catalyst; Figure 4 is a graph of the concentration of carbon monoxide at the output of an ECO device versus time according to a first electrolytic mode of a method of the present invention, wherein carbon monoxide is present at approximately 120 ppm in the input and the ECO processor uses a rhodium (RH) electrode catalyst; Figure 5 is a graph of the concentrations of carbon monoxide and carbon dioxide at the output of an ECO device versus time according to a second galvanic mode of a method of the present invention, wherein the ECO processor uses ruthenium (Ru ) as a catalyst; Figure 6 is a graph of carbon monoxide and carbon dioxide concentrations at the output of an ECO device versus time according to a first electrolytic mode of a method of the present invention, wherein the ECO processor uses Ru as the catalyst .

DETAILED DESCRIPTION OF THE INVENTION Figure 1 is a block diagram describing the different component parts of one embodiment of a method and a power generating system 10 for removing carbon monoxide from a hydrocarbon fuel and producing CD energy in accordance with the present invention. In general, a source of hydrocarbon fuel 26, such as gasoline, natural gas or methanol, is introduced into a fuel processor 27. In the fuel processor 27, hydrocarbons can react with air or water through reforming by partial oxidation or vapor to form a reforming mixture containing hydrogen, carbon monoxide, carbon dioxide, water and other minor components. The reforming mixture usually undergoes additional steps of catalytic reactions, such as a water-gas displacement reaction, to further favor the reaction between the vapor and CO to form hydrogen and C02. With the output of the fuel processor 27, a hydrogen-rich reformer 28 containing a small amount of carbon monoxide (usually less than some percentage) enters an electrocatalytic oxidation cell (ECO) 29 where the carbon monoxide is removed from the reformed 28. A reformed without carbon monoxide 32 leaves the ECO processor 29 and enters a fuel cell stack or stack 33 where the hydrogen in the reformed 32 is electrochemically oxidized at an anode by air or oxygen at a cathode to produce a power output CD 34. The operation of the fuel processor 27, the ECO processor 29 and the fuel cell stack 33 can be controlled by a central subsystem 11 that handles the necessary air, water and heat, as well as the operating instructions for each stage or step in Figure 1. More specifically, the fuel processor 27 converts the hydrocarbon fuel 26 to the reformed 28 to through multiple steps. These steps consist of reforming the fuel that includes steam reforming or partial oxidation, the water-gas displacement reaction at high temperature, the water-gas displacement reaction at low temperature, as well as the conditioning of the reformed as it can be control of the humidification and temperature through a heat transfer process. In the step of reforming by steam, the hydrocarbon fuel 26 reacts with a stream of water 12 on a reforming catalyst at an elevated temperature to form a mixture containing mainly hydrogen, carbon monoxide, carbon dioxide and others. This process is endothermic but energy efficient. Instead of steam reforming, it is possible to use a partial oxidation process in which the hydrocarbon fuel 26 reacts with a small amount of oxygen or air 13 to form a mixture of hydrogen, carbon monoxide, carbon dioxide and others. This process is exothermic and autonomous, but nonetheless less efficient in energy. After the step of steam reforming or partial oxidation, the gas mixture undergoes water-gas displacement reactions at high temperature (i.e., about 350 to 550 ° C) and at low temperature (i.e. about 200 to 300 ° C. ) in which the carbon monoxide further reacts with additional steam 12 to form hydrogen and carbon dioxide on the catalysts for water-gas displacement. In the present invention, the water-gas displacement reactions not only improve the total hydrogen yield in the fuel processor 27, they also reduce the carbon monoxide concentration, usually, unless some percentage at the exit of the reformed 28. The fuel reformation and the water-gas shift reaction above are well known in the art and are described, for example, in "Heterogeneous Catalysis in Industrial Practice" by Charles N. Satterfield, Chapter 10, page 419-465, McGraw-Hill, New York, 1991, which was incorporated herein by reference. After the water-gas displacement reaction, the reformer undergoes a conditioning process during which the humidity and temperature of the outlet of the reformer 28 is adjusted to be suitable for application to a PEFC. The humidity adjustment is made by mixing water vapor and the temperature adjustment is carried out by heat transfer through a heat exchanger. In a preferred operating condition, the temperature of the outlet of the reformed 28 should be in the range of about 70 to 100 ° C and the humidity should be so close to 100% relative humidity (RH) at the corresponding temperature. The fuel processor 27 is preferably controlled by a central management subsystem 11 as a result of the operational data 14 being transmitted between them. The central management subsystem 11 can control any number of operational parameters, such as the flow of water vapor 12, an air flow 13, a flow of refrigerant 15 to the fuel processor 27. In a preferred embodiment, a single electronic, integrated driving subsystem 11 controls not only the fuel processor 27, but also the ECO processor 29 and the fuel cell (or the fuel cell stack) 33, which are also described below. However, control of these components with separate management subsystems is considered. The detector devices (not shown) well known in the art can be installed in the fuel processor 27, the ECO processor 29, as well as the fuel cell stack 33. These detectors monitor the operation of the overall system 10 by measuring the parameters which include, but are not limited to, pressure, temperature, carbon monoxide concentration, voltage / output current, etc. These data will be part of the operational data 14, 16, 19 that will be directed to the management subsystem 11, and will receive feedback from the management subsystem 11 for the control of each operation of the unit. Particularly relevant for this invention is the carbon monoxide data collected as part of each operation data 14, 16, 19. To generate the operational data with respect to the carbon monoxide levels, the detector device according to an embodiment of The present invention is a broadband infrared absorption detector, although it is possible to use other similar devices as well. The humidified reformer 28 enters anode side 36 of the ECO cell 29 (Figure 2a) through a flow field 50 of a bipolar plate 48 (described below). It passes through a catalytic material electrode 47 that includes a catalyst metal component 41 and a catalyst support 42 described in greater detail below. Hereby, the catalytic metal component 41 chemosorbates the carbon monoxide in the reformed 28. The reference to "chemosorbe" herein is intended to refer to chemical adsorption where the electronic interaction between the CO and the active site in the metal catalytic 41 occurs to form an almost chemical bond. Subsequent references herein to "adsorb" and "chemosorbent" are used interchangeably unless otherwise specified, such as "physi-adsorption". The chemosorption of carbon monoxide occurs preferably over hydrogen. This preferential adsorption is due to an important difference in the Gibbs energies of the adsorption between carbon monoxide and hydrogen with the catalytic sites. Accordingly, the metallic component 41 preferably absorbs carbon monoxide despite the composition of the hydrocarbon reforming usually containing higher percentages of hydrogen.

Over time and in the process of adsorbing carbon monoxide, the catalytic metal component 41 finally reaches a saturation point of carbon monoxide, thereby reducing or eliminating its adsorption capacity to adsorb more carbon monoxide from the reformate 28. To maintain efficient removal of carbon monoxide from reforming 28, the catalytic metal component 41, and specifically its adsorption capacity, must be regenerated. The regeneration preferably occurs before the time when the catalytic metal component 41 reaches saturation of the carbon monoxide and, more preferably before any substantial degradation of the ability of the catalytic metal component 41 to adsorb the carbon monoxide exists. . Regeneration can occur by removing carbon monoxide from the catalytic metal component 41 through an oxidizing agent such as water vapor 12. Specifically, water vapor 12 provides transient species such as hydroxyl radicals, a hydrogen peroxide radical, etc., formed during an electrochemical process (as described below) when the water 12 is adsorbed on the surface of the catalytic metal 41. Thus, when an oxidizing agent of the activated water vapor 12 reacts chemically with the carbon monoxide that had been adsorbed by the catalytic metal component 41, the carbon monoxide is converted to carbon dioxide which is generally not harmful to the operation of the fuel cell 33. The carbon dioxide produced from the oxidation reaction has only weak physi-adsorption (it is say, the adsorption due to the van der Waals interaction). Thus, it is more easily released from the catalytic metal component 41 and is swept by the continuous flow of the reformed 28. With the adsorbed carbon monoxide now removed, the catalytic metal component 41 can again adsorb additional carbon monoxide. Accordingly, the adsorption capacity of the catalytic metal component 41 has been regenerated. To initiate the catalytic oxidation reaction between the oxidizing agent 12 and the carbon monoxide, a current is discharged through the area containing the catalytic material electrode 47 and, specifically, the catalytic metal component 41. The stream will initiate an electrochemical process that transforms the water vapor 12 adsorbed on the surface of the catalytic metal 41 to highly reactive oxidizing species. This current discharge can occur in one of two ways. As will be described in more detail below, the two forms of current discharge are known herein as galvanic and electrolytic. Regardless of the shape of the current discharge, during the regeneration period, the catalyzed oxidation reaction produces the carbon dioxide described above. The present invention also includes an adsorption cycle that is distinguished from the regeneration cycle by an absence of electric current flow and thus an absence of catalytic oxidation reactions. Preferably, a period or cycle of regeneration alternates with a period or cycle of adsorption as the concentration of carbon monoxide adsorbed to the catalytic metal component 41 increases and falls. In other words, and as an example, during the adsorption cycle, the amount of adsorbed carbon monoxide increases towards the maximum adsorption capacity of the catalytic metal component 41. Before or when the catalytic metal component 41 reaches saturation, the Adsorption is interrupted and the regeneration cycle begins, at which time the amount of carbon monoxide adsorbed falls. As can be seen, the alternation of regeneration and adsorption can theoretically continue indefinitely. Thus, for example, the adsorption cycle is initiated by preventing an electrical current from developing through the area of the catalytic metal component 41. But with partial or complete saturation of the carbon monoxide of the catalytic metal component 41, an electric current can be discharged through the area of the catalytic metal component 41 to initiate the regeneration cycle. Consequently, during the adsorption cycle, virtually the protons do not flow through the proton permeable membrane 35 of the ECO processor 29, as described in more detail below. But proton flux occurs during the regeneration cycle. Accordingly, no hydrogen consumption takes place during the adsorption period. However, during the regeneration process, a residual amount of chemosorbed hydrogen on the surface of an anode 36 (as described below) of the ECO 29 processor, as well as a gas phase in the ECO 29 processor, will participate in oxidation reactions electrochemistry on the anode 36. The electrochemical oxidation of hydrogen competes with the electrochemical oxidation of carbon monoxide and water, which are adsorbed on the catalytic metal 41. The electro-oxidation of hydrogen gives rise to the formation of protons. The protons migrate through the proton-permeable membrane 35 to the cathode 37 of the ECO 29 processor and react with reduced oxygen to form water. Since the electrochemical process that occurs during the regeneration period is usually much faster than the cumulative adsorption process, the adsorption period generally comprises a major portion of the overall ECO operation cycle. During the regeneration and adsorption cycles, a substantial amount of the carbon monoxide is removed from the reformate 32 leaving the ECO 29 processor. However, it can be seen that during the adsorption cycle, the amount of carbon monoxide in the reforming of outlet 32 will be increasing as the adsorption capacity of the catalytic metal component 41 decreases. To prevent carbon monoxide leakage in the output reforming 32, the ECO 29 processor is preferably regenerated so that the adsorption capacity of the catalytic metal component 41 can be reestablished in a timely manner. In any case, the carbon monoxide-free reformate 32 can enter the fuel cell stack 33, which can be in any design well known in the art. In the fuel cell stack 33, the reformer 32 can react with an oxidant, such as air 17, through an electrochemical process that produces an electrical energy CD 34. The by-products of the fuel cell include air exhausted from the fuel cell. oxygen 21 and a spent hydrogen reforming 22 can then be evacuated by the handling subsystem 11 in the form of exhaust gases 23. As already mentioned, Figure 2a represents the internal structure of a membrane electrode assembly of a processor ECO 29. Figure 2b depicts a bipolar plate 48 which is used on both sides of the membrane electrode assembly of Figure 2a. By this means, the ECO processor 29 is generally constructed in a manner similar to the well-known proton exchange membrane (PEM) fuel cells. These PEM cells, including the construction of bipolar plates and membrane electrode assemblies, are described in the article "Polymer Electrolyte Fuel Cells" by S. Gottesfeld and TA Zawodzinsk in ADVANCES IN ELECTROCHEMICAL SCIENCE AND ENGINEERING, RC Alkire, H Gerischer , DM Kolb and CW Tobias eds., Volume 5, pages 195-302, Wiley-VCH, Weinheim Germany, 1997 and incorporated herein by reference. The ECO 29 processor will usually operate between room temperature to approximately 180 ° C and approximately 1 to 5 atmospheres of pressure. The ECO cell 29 includes a first portion and a second portion-namely, the anode 36 and the cathode 37-together with the proton exchange membrane 35 therebetween. The different materials for the proton-permeable membrane that are well known in the art can be used as the membrane for proton exchange., such as perfluorinated polymers type NAFION®. Adsorption of carbon monoxide and electrochemical oxidation occurs on the anode side of the ECO device 29. The anode side consists of the anode 36 and the bipolar plate 48 with the conductive flow field 50. As shown in Figure 2a, the catalytic material electrode 47 includes the metal catalyst component 41 located on a conductive support of large surface area 42. On one side of the catalytic material electrode 47, and in close contact with this, is the proton exchange membrane 35. In the another side of the catalytic electrode material 47 is a porous, conductive, gas diffusion support material 44. The backing material 44 provides for the supply of the reformer 28 to the anode 36 and can be made of conductive materials with a diffusion property of gas as carbon cloths or porous carbon papers. An example of a commercial backing material 44 is ELAT ™ made by E-TEK, Inc. The side of the diffusion backing material of the gas 44 opposite the catalytic material 47 is in close contact with the bipolar plate 48 which is connected to a first conductive cable 24 (not shown). Through the bipolar plate 48 and the first conductive cable 24, the electrons are transferred between the anode 36 and an external circuit 40. The backing material 44 can be coated with a hydrophobic coating 45 to prevent local flooding of water from the process electrochemical and humidified reforming 28. An example of the hydrophobic material is fluorinated ethylene propylene (FEP). During operation, reforming 28 containing carbon monoxide enters ECO device 29 through an inlet 49 of bipolar plate 48. Reforming 28 follows the flow path or feed channel 50 through a conductive surface 51 and an outlet or exhaust 52. During the process, the reformed 28 will also pass through a backing material for gas diffusion 44 and will interact with the metal catalyst component 41. As already mentioned at the beginning, the carbon monoxide in the reformed 28 will be selectively chemosorbed on the catalyst metal component 41. Most of the carbon monoxide at the outlet 49 of the bipolar plate 48 will therefore be removed from the reforming 28. To facilitate the proton transfer process during the regeneration cycle , the catalyst metal material 41 and the support 42 are joined to the proton exchange membrane 35 in a matrix of a conductive ionomer composite of pro tones 43. The ionomer compound 43 is generally remelted from the perfluorinated sulfonic acid polymer particles. An example would be the NAFION® particles. Otherwise, the metal catalyst material 41 and the support 42 can be attached to the support material 44 through the matrix of the proton conductive ionomer compound 43 and compressed collectively against the proton exchange membrane 35 with the assembly of the ECO processor 29. The cathode 37 is preferably similar in design to the anode 36 to ensure that an oxidant such as oxygen is channeled to interact with the protons passing through the membrane 35. The catalytic metal component 41 consists of noble metals and / or transition in a highly dispersed form in support 42. Support 42 is generally characterized as electrically conductive, chemically inert, and with a high surface area. The conductivity of the support 42 may vary, but is generally comparable to that of the carbon. The need for the support 42 to be chemically inert is to avoid reactions between the reformed 28 and the support 42 during the adsorption and regeneration cycles and to maintain the structural stability of the anode 36 during the operation of the long-term ECO process. In this embodiment, the surface area of the support 42 can range from approximately 5 to 1500 m2 / g and, more preferably, in the range from about 150 to 300 m2 / g. Some examples of materials suitable for the support 42 include carbon black, metallic nitride and metallic carbide such as titanium nitride, tungsten carbide, and the like. In another embodiment of the invention, the catalytic metal component 41 can be small metallic crystallite powder without support material 42. These metal crystallites are generally highly dispersed with particle sizes in the range from 10 nm to >; 1000 nm. The benefit of using an unsupported metallic crystallite is to eliminate the requirement and limitation of the support 42. However, the unsupported metallic crystallite generally provides less available surface area than the supported catalytic metal component 41. The noble metals that are Suitable for use as the catalytic metal component 41 include, but are not limited to, ruthenium, platinum, palladium, rhodium, iridium, gold, silver, etc. Useful transition metals include, but are not limited to, molybdenum, copper, nickel, manganese, cobalt, chromium, tin, tungsten, etc. The present invention contemplates that it is possible to use two to three noble or transition metals in any combination as the catalytic metal component 41 in the form of a multiple metal alloy. However, it is preferred that one or two of the noble metals and / or one or two of the transition metals be used in any combination form as a bimetallic alloy which is demonstrated by the following examples.

Although the catalyst metal component 41 at the anode 36 and the cathode 37 can be the same, the metal catalyst component 41 at the cathode 37 is preferably different from the component at the anode 36. The preferred catalyst metal component 41 at the cathode 37 includes Platinum and transition metal-platinum alloys such as Pt-Co, Pt-Cr. The preferred catalyst metal component 41 at the anode 36 is ruthenium, rhodium, iridium, palladium, platinum and their corresponding transition metal alloys. The operation of the ECO processor 29 depends on the amount of the catalyst metal component 41 used in the assembly of the membrane electrode which is usually represented by the weight of the catalyst metal per unit area area MEA. In this invention, the preferred amount of the catalyst metal component 41 for the anode 36 is in the range of about 0.1 to 5 mg / cm2. The preferred amount of metal catalyst component 41 for the cathode 37 is in the range of from about 0.1 to 5 mg / cm2. For the catalyst material 47, the amount of the metal catalyst component 41 charged to the support 42 can also affect the operation of the ECO processor 29. For a catalytic metal component 41 based on noble metals, the metal charge on the support 42 is preferably in the range from about 2 to 70% by weight. More preferably, the filler is from about 20 to 50% by weight. Below about 2% by weight, the net amount of catalyst needed to build the anode 36 can be too high to fully utilize the metal in an electrochemical process where the proton transfer needs to be connected through the anode 36. Above 70% by weight it is difficult to obtain high dispersion of the metal which gives rise to less utilization of the metal due to the relatively lower ratio of the metal surface atom to the total metal atom. In general, it is believed that the surface metal atoms of the catalyst metal component 41 are the active sites during a catalytic reaction or a catalytic choice. For a metal catalyst component 41 based on transition metal, the metal filler is preferably in the range from about 0 to 40% by weight and, more preferably, from about 3 to 30% by weight. Charging outside this range tends to cause similar types of degradation in the operation described above for noble metals. As indicated in the above, the metal catalyst component 41 is dispersed on the substrate 42 with a high dispersion coefficient. The dispersion coefficient is defined as the ratio of the number of surface atoms of an active catalyst metal to the total number of atoms of the metal particles in the catalyst. In this embodiment, it is preferred that the catalyst metal component 41 be characterized by a dispersion coefficient between about 5 to 100% and, more preferably, between about 30 to 90%. If it is below about 15%, the catalyst surface area provided by the metal catalyst component 41 may be too low to efficiently utilize the catalyst metal. The low utilization of the catalyst metal can result in a greater amount of catalyst metal needed for the anode 36, leading to a higher cost of the ECO 29 processor. As already mentioned, the regeneration cycle is initiated by a discharge of electric current through the anode 36 or the cathode 37 of the ECO processor 29. Without pretending a limitation to any theory of electrocatalysis, it is considered that the following chemical and electrochemical processes occur during the cycles of adsorption and regeneration. During the adsorption step, the carbon monoxide in the gas phase will be chemosorbed on the active site of the catalyst metal component 41, designated as M, to form a chemosorbed CO species, CO / M, through the reaction: CO + M? CO / M (1) Meanwhile, hydrogen in the gas phase will also participate in a dissociative adsorption on the active site M through the reaction: H2 + 2M? 2H / M (2) Due to the large difference in the heat of adsorption, the surface concentration of CO / M is greater than that of H / M through the cumulative adsorption of CO. The water vapor in the humidified reformate 28 will also be adsorbed onto the surface of the anode 36 to form H2Oa S- The surface on which the water is adsorbed includes, but is not limited to, the surface of the active site M through the following equation: H20 (gas)? H20ads (3) During the regeneration stage, the following electro-oxidation reactions occur on the anode surface 36: H / M? M + H + + e (4) and H20ads? 0Hads + H + + e (5) OHas is the chemisorbed hydroxyl group on the surface of the anode 36 and which is highly reactive and can oxidize the chemosorbed CO / M through the following electrocatalytic reaction: CO / M + OHads - »M + C02 + H + + e (6) or through the direct catalytic reaction: CO / M + 20Hads - >; M + C02 + H20 (7) Another way to express the electrocatalytic oxidation of chemosorbed carbon monoxide by water is by the following equation: CO / M + H2Oads - M + C02 + 2H + + 2e '(8) The carbon dioxide formed through equations (6) to (8) it has a weak interaction with the anodic surface 36 and, therefore, will be swept out of the anode 36 after regeneration. It is possible to use two approaches during the regeneration cycle. These are the galvanic and electrolytic methods. The regeneration form is controlled by the operating subsystem 11. For the galvanic approach, the operating subsystem 11 sends a control signal that momentarily closes a two-position switch 30 between the conductive cables 24, 25, as shown in FIG. Figure 1. For the electrolytic approach, the operating subsystem 11 sends a control signal that momentarily closes the switch 30 between the conductive cables 24, 26 and a power supply CD 31. The cables 24, 25 are fixed (not shown) ) to the polar plates 48 on the sides of the anode 36 and the cathode 37 of the ECO cell 29. The conductive cables 24, 25 are preferably connected to the bipolar plates 48 which have a uniformly distributed flow field configuration. Such a configuration is a coil pattern, as shown in Figure 2b. The bipolar plates have uniform and narrow contact with the conductive backing material 44 and, therefore, with the anode 36 and the cathode 37. The uniform and narrow contact causes a uniform flow of electrical current through the catalytic material 47, achieving by This means the most efficient degree of regeneration. Although it is possible to use a synchronized cycle for the frequency necessary for regeneration, the preferred embodiment uses measurements or calculations of carbon monoxide concentrations at the output of the fuel processor 27 and the ECO processor 29 to initiate the regeneration cycle. In the galvanic mode, the current is produced exclusively from a galvanic reaction due to the potential transient difference between the anode 36 and the cathode 37 of the ECO processor 29. The circuit 40 established between the anode 36 and the cathode 37 has a very small resistance or zero The low impedance allows an instantaneous current to pass between the anode 36 and the cathode 37 when the switch 30 closes the circuit. Under such a condition, the electrooxidation reaction of carbon monoxide with water at the anode to form carbon dioxide is accelerated according to the aforementioned equation (8). As already indicated, in view of the fact that the carbon dioxide has a relatively weak adhesion to the surface of the anode 36, it can be swept by the reformer 28 which continues its passage through the ECO cell 29. In the electrolytic mode, the previous circuit 40 further comprises a separate power supply or CD 31 cell, with voltage in the range usually from about 0.1 to 2.0 volts, which applies the external potential and current on the initial discharge of the electric current. When the switch means 30 is closed, the first conductive cable 24 of the anode 36 is operably connected to a positive terminal of the CD cell 31 and the second conductive cable 25 of the cathode 37 is operably connected to a negative terminal of the cell CD 31. Upon receiving an "inverted" potential from the energy supply 31, oxidant species will be produced as a result of reactions similar to those given in equation (5) above. Oxidizing species include, but are not limited to, hydroxyl groups, hydroperoxide groups, etc. These oxidizing species can be formed on the surface of the catalyst metal component 41 or other parts of the anode 36 and migrate to the catalyst metal component 41. The oxidizing species can then react with the adsorbed carbon monoxide to form carbon dioxide. As in the previous galvanic mode, the weakly adsorbed carbon dioxide will be entrained by the reforming flow 28, leaving the surface of the anode 36"clean". In the galvanic and electrolytic methods, the duration of the regeneration is also controlled by the management system 11. The duration of the regeneration can be greater than 0 to about 100 seconds. The preferred embodiment of the present invention is from about 0.01 seconds to 10 seconds.

Although the above description refers to a single ECO 29 cell, it is possible to use multiple ECO 29 cells to improve the total CO removal capacity. These multiple ECO 29 cells may be electrically connected in a series or in a parallel pattern, similar to the well-known patterns used in fuel cell stacks. In addition, and as with the fuel cells, the ECO cells 29 may be stacked in a module, wherein the individual cells 29 are electrically connected in series; a plurality of modules can then be connected in parallel flow. The regeneration of the multiple ECO 29 cells can occur simultaneously or sequentially. However, the sequential form is preferred. In addition, the manner in which reforming 29 flows in the multiple ECO 29 cells can also be in parallel or in series, which is also similar to flows for fuel cell stacks. The serial flow pattern is preferred for more complete removal of carbon monoxide.

EXAMPLES Figure 3 graphically describes test data where an ECO cell was constructed with a similar configuration as a fuel cell with a common proton exchange membrane (PEM). On the anode side of the membrane electrode assembly (MEA), a catalytic bimetal electrode Pt-Ru with carbon support, with a loading of 0.299 mg / cm2 was joined by the hot compression method described in the US Patent No 5,211,984 and which is incorporated herein by reference. Similarly, a Pt / C electrode catalyst with a Pt load of 0.303 mg / cm2 was joined on the cathode side. The MEA had an electrode surface area of 5 cm2 and the ECO device was operated at 80 ° C. The gaseous mixture of the anode was fully humidified nitrogen containing 1014 ppm of carbon monoxide. The gas mixture was introduced through the anode side of the ECO cell at a flow rate of 128 cm2. The cathode gas was fully humidified air at a flow rate of 180 cm2. Separate, wide-band IR absorption detectors were used to monitor carbon monoxide and carbon dioxide concentrations at the output of the ECO cell. Figure 3 shows that, at the beginning of the experiment, the concentration of carbon monoxide within the gaseous mixture at the outlet decreased significantly as the carbon dioxide concentration increased, indicating the selective absorption of carbon monoxide and oxidation catalytic that occurred on the surface of the electrode catalyst. With the saturation of carbon monoxide on the anode, the concentration of carbon monoxide in the gas phase returned to the original level. At this point, the galvanic regeneration was initiated by electrically cutting the circuit between the anode and the cathode for one second to allow electrocatalytic oxidation to occur at the anode surface. After the short circuit, the carbon monoxide concentrations in the gas mixture decreased and the carbon dioxide increased, indicating that the adsorbed carbon monoxide was oxidized to carbon dioxide and the surface of the electrode was cleaned for another cycle of adsorption. The process was highly repeatable, as seen in Figure 3. Figure 4 graphically describes the test data in an ECO device similar to that used in Figure 3 and at an operating temperature of 80 ° C. On the anode side of the membrane electrode assembly, an oxide-supported rhodium-plated electrode catalyst of Rh load of 0.270 mg / cm2 was joined by the thermocompression method. Similarly, a catalyst Pt / C electrode with Pt loading of 0.330 mg / cm2 was attached on the cathode side. During the experiment, a synthetic reforming mixture containing 120 ppm of CO, 19.9% of C02, 37.0% of H2, and the difference of N2 was completely humidified and passed through the anode side of the ECO cell with a flow velocity of 128 cm2 while air with a relative humidity of almost 100% passed through the cathode side at a flow rate of 180 cm2. A broad band IR absorption detector monitored the carbon monoxide concentration at the outlet. At the beginning of the experiment there was a significant decrease in the concentration of carbon monoxide in the flow of the reformed at the output of the ECO cell, indicating selective absorption of carbon monoxide by a catalytic material within the anode. With the carbon monoxide saturation of the catalytic material, it was observed that the carbon monoxide in the gas phase increased to approximately its original level. At this point, the two electrodes of the ECO cell were connected to an external DC power supply with 0.4 volts, with the positive cable from the power supply attached to the anode of the ECO cell and the negative cable attached to the cathode of the ECO cell , thus producing an "inverted voltage potential". The connection lasted a short period of one second to initiate electrocatalytic oxidation on the surface of the anode. As seen in Figure 4, with the repeated cycles, the carbon monoxide levels in the reformate were reduced through the electrocatalytic oxidation process in a manner consistent with what was expected by the regeneration of the catalytic material by absorbing carbon monoxide . Figure 5 graphically describes the test results of an experiment with an ECO cell similar in construction to that used in connection with Figure 3. The anode electrode catalyst was Ru / C with the ruthenium loading at 0.3 mg / cm2 . The operating temperature was again 80 ° C. A completely humidified gas mixture containing 492 ppm of carbon monoxide and hydrogen difference was introduced on the anode side at a flow rate of 128 cm 2. At the same time, humidified 100% air passed through the cathode side with a flow rate of 180 cm2. Separate broadband IR absorption detectors monitored the carbon monoxide and carbon dioxide concentrations at the ECO output. As shown in Figure 5, at the beginning of the experiment, the concentration of carbon monoxide at the outlet decreased while the concentration of carbon dioxide increased, indicating the selective adsorption of carbon monoxide and the catalytic oxidation occurring on the surface of the carbon monoxide. electrode catalyst. With the saturation of carbon monoxide on the anode, the concentration of carbon monoxide in the gas phase returned to the original level. At this point, the two electrodes of the ECO cell were connected for one second to allow electrocatalytic oxidation to occur at the anode surface. After this short circuit, carbon monoxide depletion and carbon dioxide enhancement were observed in the reformate, indicating that the adsorbed carbon monoxide had been oxidized to carbon dioxide and the electrode surface was clean for another adsorption cycle. The process was highly repeatable, as shown in Figure 5. With an increase in the frequency of regeneration, such as a second of the short circuit for almost 15 seconds of carbon monoxide adsorption, the carbon monoxide level in the output can be maintained at a constant level, as shown in Figure 5. Figure 6 graphically describes the results of the test with an ECO cell of similar construction and chemical concentrations, temperature and humidity identical to those used to obtain the test results described in Figure 5. The only difference in the equipment that produces the results in Figures 5 and 6 of the addition of an external CD power supply with a potential of 0.4 volts in the tests represented by Figure 6. With the saturation of carbon monoxide on the anode, the concentration of carbon monoxide in the gas phase returned to the original level. At this point, the two electrodes of the ECO cell were connected to the power supply, with the positive cable of the power supply attached to the anode of the ECO cell and the negative cable attached to the cathode of the ECO cell, thus producing a "potential" of inverted voltage ". Figure 6 illustrates that, when the inverted voltage was applied for approximately one second, the adsorbed carbon monoxide was electrochemically oxidized to carbon dioxide, as indicated by the depletion of carbon monoxide and the increase of carbon dioxide at the output of the ECO device. This process was highly repeatable, as shown in Figure 6. With an increase in the frequency of regeneration, such as a second of applying an "inverted voltage" during every 20 seconds of carbon monoxide adsorption, the level of Carbon monoxide at the outlet can be maintained at a constant level, as shown in Figure 6. As can be appreciated by those skilled in the art, the present invention offers a method for improving the performance of a fuel cell with efficiency by eliminating monoxide from carbon of the hydrogen fuel externally. The present invention provides advantages of a high degree of removal of carbon monoxide, simple configuration of the system, low parasitic consumption of hydrogen, increase in tolerance for the dynamics of the carbon monoxide outlet of the reforming, and ease of operation. Although a primary application of the invention is to reduce the concentration of carbon monoxide with the hydrogen fuel for the operation of the fuel cell, the present invention may have other applications where removal of carbon monoxide is necessary. It should be understood, of course, that the above refers to the preferred embodiments of the invention and that it is possible to make modifications without departing from the spirit and scope of the invention as set forth in the following clauses.

Claims (41)

1. A method for removing carbon monoxide from a reformed hydrocarbon, the method comprises the steps of: moving the reformed through a catalytic electrode material to adsorb preferably carbon monoxide with the catalytic electrode material so as to reduce a adsorption capacity of the catalytic electrode material; produce an electric current through the catalytic electrode material that has adsorbed carbon monoxide; and converting the carbon monoxide that has been adsorbed onto the catalytic material to carbon dioxide to thereby generate the adsorption capacity of the catalytic electrode material.

The method of claim 1, wherein the step of producing an electrical current occurs before the catalytic electrode material is saturated with carbon monoxide.

The method of claim 1, wherein the step of producing an electric current occurs when the catalytic electrode material becomes saturated with carbon monoxide.

4. The method of claim 1, wherein the step of producing an electric current occurs in galvanic form.

The method of claim 1, wherein the step of producing an electric current occurs electrolytically.

6. The method of claim 1 further comprises the step of flowing the reformate through a plurality of electrocatalytic processors.

The method of claim 6, wherein the processors are electrically connected in a series or parallel pattern.

The method of claim 6, wherein the processors are connected by flow in a pattern in series or in parallel.

The method of claim 6, wherein the processors are stacked in a plurality of modules, the processors being electrically connected in series in one of the modules, and the modules being connected in parallel for the flow.

The method of claim 6, wherein the step of converting carbon monoxide occurs sequentially in the processors.

11. A method for removing carbon monoxide from hydrocarbon reforming, the method comprising the steps of: humidifying the reformate to, thereby, form a humidified reformate; moving the humidified reformate through a first portion of a cell containing a catalytic material; preferably adsorbing the carbon monoxide in the catalytic material so as to reduce an adsorption capacity of the catalytic material; producing an electric current through the catalytic material that has adsorbed carbon monoxide, the electric current produced in galvanic form, in the absence of an external energy source, by an electrical circuit between the first portion and a second portion of the cell; and converting the carbon monoxide that has been adsorbed on the catalytic material to carbon dioxide to thereby regenerate the adsorption capacity of the catalytic material.

The method of claim 11, wherein the first portion consists of an anode of the cell and the second portion consists of a cathode of the cell.

13. A method for removing carbon monoxide from a hydrocarbon reforming, the method comprising the steps of: humidifying reforming to thereby form a humidified reforming; moving the humidified reformate through a first portion of a cell containing a catalytic material; preferentially adsorbing the carbon monoxide in the catalytic material so as to reduce an adsorption capacity of the catalytic material; producing an electric current through the catalytic material that has adsorbed the carbon monoxide, the electric current being produced electrolytically, in the presence of an external energy source, by an electrical circuit between the first portion and a second portion of the cell; converting the carbon monoxide that has been adsorbed onto the catalytic material into carbon dioxide to thereby regenerate the adsorption capacity of the catalytic material.

The method of claim 13, wherein the first portion consists of an anode of the cell and the second portion consists of a cathode of the cell.

15. A method for providing DC power from a reforming of hydrocarbons containing carbon monoxide, consists of the steps of: humidifying the reforming to thereby form a humidified reforming; moving the humidified reformate through a catalytic material that adsorbs carbon monoxide in preference to hydrogen; producing an electric current through the catalytic material to thereby convert the carbon monoxide that has been adsorbed onto the catalytic material into carbon dioxide; produce a reformate substantially free of carbon monoxide; pass the reformed without carbon monoxide to a fuel cell to produce CD energy.

16. The method of claim 15, further comprising the step of regenerating an adsorption capacity of the catalytic material.

17. The method of claim 15, wherein the step of producing an electric current occurs in galvanic or electrolytic form.

18. The method of claim 15, wherein the step of producing an electric current occurs cyclically with time.

19. An electrocatalytic oxidation processor for removing carbon monoxide within a hydrocarbon reformate, the electrocatalytic oxidation processor comprising: a pair of bipolar plates; a first portion containing a catalytic material that preferably adsorbs carbon monoxide, the first portion being located intermediate to the bipolar plates; a second portion separated from the first portion by a membrane permeable to protons, the second portion being located intermediate to the bipolar plates; and an electrical circuit comprising a first conductive cable electrically connected to the first portion and a second conductive cable electrically connected to the second portion.

The processor of claim 19, wherein the electrical circuit further consists of a switch electrically connected in series with the first and second wires so that when the switch changes from an open state to a closed state, electrical continuity is established between the first portion and the second portion.

21. The processor of claim 19 further comprises a power source connected to the electrical circuit.

The processor of claim 19, wherein the first portion comprises a first catalytic material and the second portion comprises a second catalytic material.

The processor of claim 19, wherein the catalytic material consists of a metal component.

The processor of claim 23, wherein the catalytic material further consists of a support on which the metal component is located.

25. The processor of claim 24, wherein the support is characterized by a surface area between about 5 to 1500 m2 / g.

26. The processor of claim 19, wherein the catalytic material is characterized by a dispersion coefficient between about 5 to 100%.

27. An electrocatalytic oxidation system for reducing a concentration of carbon monoxide within a reformed hydrocarbon, the electrocatalytic oxidation system consists of: a plurality of electrocatalytic processors, at least one of the processors consists of: an anode; a cathode; a membrane permeable to protons located operably between the anode and the cathode; and an electric current between the anode and the cathode, the electrical circuit producing an electrical current through a galvanic reaction or an electrolytic reaction.

28. The system of claim 27, where the electrical circuit also consists of a switch, which when it changes from an open to a closed state, completes the electrical circuit.

29. The system of claim 27 further comprises a DC power source in communication with the electrical circuit.

The system of claim 27, wherein the anode consists of a first catalytic material and the cathode consists of a second catalytic material.

The system of claim 30, wherein the first and second catalytic materials consist of a metal component selected from a group consisting of noble metals, transition metals and mixtures thereof.

32. The system of claim 30, wherein the first and second catalytic materials consists of an elaborate support of an electrically conductive medium.

33. The system of claim 32, wherein the supports is selected from the group consisting of: carbon black, titanium nitride, titanium aluminum nitride, and tungsten carbide.

34. The system of claim 32, wherein the metal component is characterized by a load on the support between about 2 to 70% by weight.

35. The system of claim 32, wherein the metal component is present at about 0.1 to 5.0 mg / cm2.

36. The system of claim 27, wherein the processors are electrically connected in a pattern in series or in parallel.

37. The system of claim 27, wherein the processors are connected for flow in a series or parallel pattern.

38. The system of claim 27, wherein the processors are stacked in a plurality of modules, the processors being electrically connected in series in one of the modules, the modules being connected in parallel for the flow.

39. The system of claim 27, wherein the conversion step of carbon monoxide occurs sequentially in the processors.

40. A system for carbon monoxide removal consists of: a fuel processor that processes a hydrocarbon fuel containing carbon monoxide; a processor for the electrocatalytic oxidation downstream of the fuel processor, the oxidation processor comprises a catalytic material having a support in a metallic component, the catalytic material being able to adsorb the carbon monoxide in preference to hydrogen in the hydrocarbon fuel; and an electrical circuit that produces an electric current through the catalytic material to convert the carbon monoxide that is adsorbed onto the catalytic material into carbon dioxide.

41. The system of claim 40 further comprises an electronic steering system in communication with the fuel processor, the oxidation processor and the electrical circuit.