WO1999053560A1 - Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels - Google Patents

Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels Download PDF

Info

Publication number
WO1999053560A1
WO1999053560A1 PCT/US1998/007373 US9807373W WO9953560A1 WO 1999053560 A1 WO1999053560 A1 WO 1999053560A1 US 9807373 W US9807373 W US 9807373W WO 9953560 A1 WO9953560 A1 WO 9953560A1
Authority
WO
WIPO (PCT)
Prior art keywords
hydrogen
membrane
fuel
cell
fuel cell
Prior art date
Application number
PCT/US1998/007373
Other languages
French (fr)
Inventor
Omar Yepez
Original Assignee
Westfield Trading Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westfield Trading Corporation filed Critical Westfield Trading Corporation
Priority to PCT/US1998/007373 priority Critical patent/WO1999053560A1/en
Priority to AU71126/98A priority patent/AU7112698A/en
Publication of WO1999053560A1 publication Critical patent/WO1999053560A1/en

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/86Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/8605Porous electrodes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00Fuel cells; Manufacture thereof
    • H01M8/08Fuel cells with aqueous electrolytes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00Fuel cells; Manufacture thereof
    • H01M8/10Fuel cells with solid electrolytes
    • H01M8/1007Fuel cells with solid electrolytes with both reactants being gaseous or vaporised
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/50Fuel cells

Definitions

  • This invention relates to an anode for fuel cells, which are able, by the use of hydrogen permeation, to electroxidize carbon compounds continuously at room temperature.
  • a Nonpoisoning fuel cells driven by hydrogen and carbonaceous fuels and methods of operating them is described.
  • Fuel cells have long been regarded as a useful future source of electric power. However, near room temperature commercial fuel cells heretofore have had to run only with hydrogen and have to use platinum as electrocatalyst. The need to use only pure hydrogen has driven the research of fuel cell to consider carbonaceous fuel processing in order to produce pure hydrogen.
  • simple organic compounds such as methanol, formaldehyde or formic acid, as direct fuel cells fuels , presents several advantages. They are relatively non- toxic, easy to store and handle and they possess a high energy density of the order of 1 W/Kg. Also, theoretically, fuel cells which burn carbonaceous fuels directly with air as oxidant have higher efficiencies than hydrogen fuel cells.
  • a new process has been developed which combines electrochemical reactions and the chemical reaction between occluded hydrogen and the carbon monoxide, formed during the electroxidation of a carbonaceous fuel at room temperature.
  • One of the possible reduction reaction paths for CO 2 involves carbon monoxide, CO, which has been designated as the poison in the electrochemical oxidation of carbonaceous compound.
  • the hydrogen permeation should assist the complete electrochemical oxidation of a carbonaceous compound towards CO 2 .
  • the hydrogen permeation should assist the complete electrochemical oxidation of a carbonaceous compound towards CO 2 .
  • a novel fuel cell which uses, as a fuel, a carbon compound which undergoes a direct electrochemical oxidation in the fuel cell at room temperature.
  • This cell comprises: a cathode, an electrolyte, and an anode.
  • the anode, of the present invention has three faces: a first face that is fluid permeable, a second face which is in contact with the electrolyte, and also serves as the reaction insertion face and a third face, which is in contact with hydrogen, is designated as the hydrogen absorption face.
  • the second and the third faces when considered together comprise an atomic hydrogen transmissive membrane which store and diffuses hydrogen in atomic form.
  • the hydrogen absorbed at the third face diffuses through the membrane and appears at the second face, where the direct electrochemical oxidation 3 of a carbonaceous compound and the poisoning of the anode both take place. Then, the occluded hydrogen reacts with the poisons, the product of this reaction undergoes an electrochemical oxidation and, as a consequence, the surface is cleaned, presenting new reaction sites for the continuous electrochemical oxidation of said carbonaceous compound.
  • the membrane material is selected from the group of metals consisting of Pd, Ni, Ti, Fe, V, Ta, Cu, Ag, Au, and the alloys and mixtures thereof.
  • the insertion reaction side of the membrane comprises electrocatalytic particles, which are suitably selected from the group of metals consisting of Pt, Pd, Ni, Ti, Fe, V, Cu, and alloys thereof, and hydrogen permeation nickel alloys. It is furthermore desirable that the insertion reaction side is in contact with colloidal polytetrafluorethylene and with an electrolyte capable of tolerating carbonation.
  • an electrolyte is selected from the group consisting of aqueous sodium bicarbonate, phosphoric acid and solid electrolytes, such as Nation ® .
  • This method comprises the sequential steps of: a. absorbing hydrogen from a source thereof on the absorption side of the atomic hydrogen transmissive membrane, b. passing hydrogen in atomic form, through the membrane to the opposite insertion reaction side of this membrane, c. providing a carbon compound to this insertion reaction side, d. allowing the direct electrochemical oxidation reaction of the carbon compound on the insertion reaction side to give an electrochemical oxidation product, 4 e. chemically reacting this product with the hydrogen passed through the membrane to give a reduction reaction product, f.
  • step (e) further electrochemically oxidizing this reduction reaction products of step (e) to provide carbon dioxide, as the principal product of the complete electrochemical oxidation of the carbon compound; and g. reducing air oxygen to air at the cathode, and drawing electricity generated thereby in said fuel cell from the cathode and anode thereof.
  • the fuel may be a fossil fuel, such as gasoline, kerosene or gas oil. It may also be a C-1 to C-6 alkane, such as methane, ethane, propane or butane. It may also be a C-1 to C-6 alcoh. ' . such as methanol, ethanol, propanol or butanol. It may also be carbon monoxide (CO).
  • the hydrogen containing medium may be hydrogen gas, hydrogen containing gas or hydrogen containing vapor.
  • the process includes a further step of supplying electrolytically formed hydrogen at the hydrogen absorbing surface of the membrane. It is preferred to supply hydrogen to the hydrogen absorbing membrane at a rate sufficient to establish a concentration gradient across said membrane which drives the hydrogen through it.
  • This molecular hydrogen is absorbed at the steam reforming side of a hydrogen permeable membrane, 5 4 H 2 ⁇ 8 H*
  • H* The occluded atomic hydrogen, H*, passes through the membrane to the fuel cell side, where it undergoes an electrochemical oxidation in accordance with the equation 8 H* ⁇ 8 H + + 8 e
  • each methane molecule produces 8 electrons, and the potential at zero current of this cell is 1 ,09 Volts.
  • the present invention provides a path around this problem: 6
  • the atomic hydrogen (H*) chemically reacts with the carbon monoxide adsorbed on the anode and transforms it into formaldehyde which then desorbs from the anode:
  • Figure 1 is a schematic representation of a non-poisoning fuel cell of the present invention.
  • Figure 2 is an schematic cross view of the non-poisoning anode.
  • Figure 3 is a diagrammatic representation of the chemical and electrochemical processes occurring at the inside of the anode of figure 1 .
  • Figure 4 is a schematic diagram showing the details of a compact electrodes test fuel cell, together with an ampermeter used to test its operation.
  • Figure 5 is a cyclic voltammetry of a palladium wire electrode, with no initially occluded hydrogen in NaOH 0.5 M.
  • Figure 6 is a cyclic voltammetry of a palladium wire electrode of Figure 5, deliberately loaded with hydrogen, in NaOH 0.5 M.
  • Figure 7 is a cyclic voltammetry of a palladium wire electrode of Figure 6, without occluded hydrogen in an aqueous 0.26 M NaHCOO and 0.24 M NaOH.
  • Figure 8 is a cyclic voltammetry of a palladium wire electrode of Figure 7 after 50 Coulombs of hydrogen were deliberately occluded .
  • Figure 9 shows the comparison between different current transitories obtained when a + 300 mV (SCE) potential pulse is applied on: 2.1 ) electroxidation of 2 Coulombs of occluded hydrogen in 0.5 M NaOH. 2.2) electroxidation of formate (HCOO ) on a palladium wire without occluded hydrogen and 2.3) electroxidation of formate (HCOO ) on a palladium wire with 2 Coulombs of occluded hydrogen.
  • Figure 10 is a cyclic voltammetry of a palladium wire electrode, without occluded hydrogen in an aqueous 0.5 M NaOH and 0.2 M methanol. 8
  • Figure 1 1 is a cyclic voltammetry of a palladium wire electrode of Figure 10, with 50 C of occluded hydrogen.
  • Figures 1 2 through 1 3 show current (I in milliamps) transitories (t in minutes) for different fuels in the compact electrodes fuel cell described in Figure 4.
  • Figure 1 0.2 molar methanol and a saturated bicarbonate solution on palladium loaded with hydrogen.
  • Figure 1 0.2 molar ethanol and a saturated bicarbonate solution on palladium loaded with hydrogen.
  • Figure 14 0.2 molar sucrose and a saturated bicarbonate solution on palladium loaded with hydrogen.
  • FIG. 1 is an schematic representation of the fuel cell arrangement of the present invention.
  • This comprises a cathode 1 provided with oxygen or air input means 2 and water output means 3.
  • the cell further comprises a non-poisoning anode 4, which comprises a net of capillaries 5, surrounded by a hydrogen supply line 6, originating in the catalytic steam reformer 7.
  • the cell has a primary carbonaceous fuel input means 8 and a carbon dioxide output means 9.
  • the electrolyte 10 is sandwiched between cathode 1 and anode 4.
  • Hydrogen may be supplied by any source of hydrogen, however, it has been found useful to utilize a catalytic steam reformer 7 which is provided with a hydrogen source fuel through conduit 1 1 and carbon dioxide generated in said reformed exits through exit port 1 2. Alternatively the hydrogen may be electrolytically generated.
  • the electricity generated by the system is taken off via cathode conduit 13 and anode conduit 14.
  • FIG 2 a transverse view of the non-poisoning anode 4 is diagrammatically illustrated.
  • the first face of the anode is a fluid permeable face 1 5
  • the body of the anode itself is made of a net of low thickness tubes or capillaries 5 made of a hydrogen permeation nickel 9 alloy or the like. This provides a holed structure to enable the molecular hydrogen to go into the third face 16 and diffuses through the tube wall 17 to the second face 18 of the anode.
  • the outside of the tubes can be coated with platinum, palladium or similarly active particles 19 and with polytetrafluorethylene particles 20 or the like. The spaces between tubes act as meniscus areas .
  • the hydrogen which passes through the capillaries 5 of the anode can react at the outside of the tubes or be ad/absorbed by the electrocatalytic particles 19 to react at their surfaces.
  • a flat screen made of a porous hydrogen storing material such as nickel alloys or the like. Since the hydrogen goes into the anode material through its side, however, in the later case hydrogen diffusion will be less than in the net of tubes or capillaries.
  • the electrolyte can be , for example, sodium bicarbonate, phosphoric acid or a room temperature solid electrolyte.
  • Hydrogen from an appropriate source is continuously pumped into the net of capillaries 5 of the anode 4 , to keep the outside of the capillaries and/or the electrocatalytic particles 19 saturated with it.
  • hydrogen is not used up in the subsequent electrochemical reactions, the hydrogen that does not reacts with the poisons, will electrochemically oxidize to protons, so a continuous hydrogen feed is needed.
  • Air or a similar source of oxygen is then supplied, via conduit 2, to cathode 1 which should, preferably, be made of the state of the art gas diffusion porous electrode, and simultaneously therewith the primary fuel which can be in gaseous or liquid form, is applied through conduit 8 to anode 4.
  • cathode 1 which should, preferably, be made of the state of the art gas diffusion porous electrode, and simultaneously therewith the primary fuel which can be in gaseous or liquid form, is applied through conduit 8 to anode 4.
  • the potential in the cell generated in accordance with the equations set forth above are then taken off from the anode via conduit 14 and the cathode via conduit 13.
  • SCE 242 mV vs. Normal Hydrogen Electrode
  • Cyclic voltammetry consists in measuring the current that floes through the working electrode, while a continuous positive and negative voltage ramps are applied on it. This is done by a potentiostat, and in this experiments, a voltage speed of 50 mV/s was used.
  • Q nF
  • Figure 5 is a cyclic voltammetry of a palladium wire electrode, with no initially occluded hydrogen in NaOH 0.5 M. It shows the formation of palladium oxide pick (a),
  • Control 2 Hartner (US patent 3393098) Process Example Figure 6 shows the cyclic voltammetry of the palladium electrode of Control 1 after initial occlusion of 50 C of hydrogen in the metal. Between 0 and + 300 mV (SCE), there is an oxidation wave diminishing in each potential cycle, which is due to hydrogen, coming from the inside of the electrode, and undergoes an electrochemical oxidation.
  • SCE + 300 mV
  • Figure 7 is a cyclic voltammetry of the palladium electrode of Control 1 , without occluded hydrogen in an aqueous 0.26 M NaHCOO + 0.24 M NaOH.
  • Peak (a) is due to the formate oxidation to CO 2 .
  • the current increases with potential.
  • CO is being generated, it strongly adsorbs on the electrode surface and poisons it.
  • the current no longer increases and falls to almost zero, generating peak (a), HCOO • + OH ⁇ CO 2 + H 2 O + 2 e ' HCOO ⁇ CO + OH
  • palladium oxide is formed and the strongly adsorbed CO is also oxidized
  • Example 2 The Process of the Present Invention Figure 8 is a cyclic voltammetry of the palladium wire of Example 1 , after 50 C of hydrogen were deliberately occluded. The current continuosly increases with the potential, the peak (a) (observed in Figure 7) has disappeared, because the non-poisoning reaction, already described is taking place,
  • FIG. 10 Electroxichemical Oxidation of Methanol (Poisoning Effect Example)
  • Figure 10 is a cyclic voltammetry of the palladium electrode of Control 1 , without occluded hydrogen in an aqueous 0.2 M CH 3 OH (methanol) + 0.5 M NaOH. 15
  • Peak (a) is due to the methanol oxidation to CO 2 .
  • the current increases with potential.
  • CO in this process CO is being generated, it strongly adsorbs on the electrode surface and poisons it. The current no longer increases and falls to almost zero, generating peak
  • Example 4 The Process of the Present Invention with methanol as a fuel
  • Figure 1 1 is a cyclic voltammetry of the palladium wire of Example 3, after 50 C of hydrogen were deliberately occluded. The current continuosly increases with the potential, the peak (a) (observed in Figure 10) has disappeared, because the non-poisoning reaction, is taking place,
  • FIG. 4 An apparatus that simulate a fuel cell, for carrying out test experiments which are set forth in the examples 5 through 7 (below), regarding to the process of the present invention.
  • This apparatus comprises a two-part cell having an anode sector 21 and a cathode sector 22.
  • the cathode sector 22 is further provided with oxygen input means 23.
  • the two sectors are separated by a sintered glass barrier 24 permeable to ion flow.
  • An anode of palladium 25 is provided in sector 21 and a platinum cathode 26 is provided in sector 22.
  • An ammeter 27 is connected to anode 25 via conduit 28 and to cathode 26 via conduit 29.
  • a 1 cm 2 area palladium electrode 25 was occluded with hydrogen up to 1 50 C, at constant current, in a two electrodes electrochemical cell, using perchloric acid 0.5 M as electrolyte. Then the palladium electrode was transferred to the compact electrode fuel cell of Figure 4, where, as the non-poisoning effect of the occluded hydrogen is taking place, an spontaneous flow of current is expected and measured by the ammeter. This experiment were performed at room temperature.

Abstract

Fuel cell of the type that uses, as a fuel, a carbon compound which undergoes electroxidation in said fuel cell. This cell comprises: a cathode (1), an electrolyte (10), and an anode (4). The anode has a first face that is fluid permeable and a second face which is in contact with the electrolyte. The second face comprises an atomic hydrogen transmissive membrane (5) made of an electrocatalytic metallic element which stores and diffuses hydrogen in atomic form. This membrane has an absorption side and an opposite insertion reaction side. There is also provided a method of generating electricity in a fuel cell as described generally and in any of the specific embodiments described above. This method comprises the sequential steps of: absorbing a hydrogen containing medium on the absorption side of the atomic hydrogen transmissive membrane, passing hydrogen in atomic form, through the membrane to the opposite insertion reaction side of this membrane, providing a carbon compound to this insertion reaction side, allowing the direct electroxidation reaction of the carbon compound on the insertion reaction side to give an electroxidation product, chemically reacting this with the hydrogen passed through the membrane to give a reduction reaction product, further electroxidizing this reduction reaction product to provide carbon dioxide, as the principal product of the complete electrochemical oxidation of the carbon compound; and drawing electricity generated thereby in said fuel cell from its cathode and anode.

Description

1
NONPO.SONING FUEL CELL AND METHODS OF OPERATING THE SAME WITH CARBONACEOUS FUELS
FIELD OF INVENTION
This invention relates to an anode for fuel cells, which are able, by the use of hydrogen permeation, to electroxidize carbon compounds continuously at room temperature. A Nonpoisoning fuel cells driven by hydrogen and carbonaceous fuels and methods of operating them is described.
BACKGROUND OF THE INVENTION
Fuel cells have long been regarded as a useful future source of electric power. However, near room temperature commercial fuel cells heretofore have had to run only with hydrogen and have to use platinum as electrocatalyst. The need to use only pure hydrogen has driven the research of fuel cell to consider carbonaceous fuel processing in order to produce pure hydrogen. However, the use of simple organic compounds such as methanol, formaldehyde or formic acid, as direct fuel cells fuels , presents several advantages. They are relatively non- toxic, easy to store and handle and they possess a high energy density of the order of 1 W/Kg. Also, theoretically, fuel cells which burn carbonaceous fuels directly with air as oxidant have higher efficiencies than hydrogen fuel cells. Unfortunately, carbonaceous fuel cells experience rapid electrocatalyst poisoning due to formation ofcarbon monoxide (Parson and Vandernoot, Electroanal. Chem., 257 (1988) 9). Hartner et al. (US patent 3393098) developed the principle of using a hydrogen permeation membrane, to separate CO from the hydrogen that is produced from the partial combustion of carbonaceous compounds. In this way, the poisoning of the anode is avoided, since only hydrogen reaches the other side of the membrane, where it is electrochemical 2 oxidized. Ayers (US patent 4547273) uses a hydrogen permeation membrane to assist the electrochemical reduction of carbon dioxide, CO2, with hydrogen generated electrochemically.
SUMMARY OF THE INVENTION
A new process has been developed which combines electrochemical reactions and the chemical reaction between occluded hydrogen and the carbon monoxide, formed during the electroxidation of a carbonaceous fuel at room temperature. One of the possible reduction reaction paths for CO2 involves carbon monoxide, CO, which has been designated as the poison in the electrochemical oxidation of carbonaceous compound. Following the principle of microscopic reversibility, the hydrogen permeation should assist the complete electrochemical oxidation of a carbonaceous compound towards CO2. Following the principle of microscopic reversibility, the hydrogen permeation should assist the complete electrochemical oxidation of a carbonaceous compound towards CO2.
There is provided a novel fuel cell which uses, as a fuel, a carbon compound which undergoes a direct electrochemical oxidation in the fuel cell at room temperature. This cell comprises: a cathode, an electrolyte, and an anode. The anode, of the present invention, has three faces: a first face that is fluid permeable, a second face which is in contact with the electrolyte, and also serves as the reaction insertion face and a third face, which is in contact with hydrogen, is designated as the hydrogen absorption face. The second and the third faces, when considered together comprise an atomic hydrogen transmissive membrane which store and diffuses hydrogen in atomic form. In this arrangement, the hydrogen absorbed at the third face diffuses through the membrane and appears at the second face, where the direct electrochemical oxidation 3 of a carbonaceous compound and the poisoning of the anode both take place. Then, the occluded hydrogen reacts with the poisons, the product of this reaction undergoes an electrochemical oxidation and, as a consequence, the surface is cleaned, presenting new reaction sites for the continuous electrochemical oxidation of said carbonaceous compound.
Suitably, the membrane material is selected from the group of metals consisting of Pd, Ni, Ti, Fe, V, Ta, Cu, Ag, Au, and the alloys and mixtures thereof. The insertion reaction side of the membrane comprises electrocatalytic particles, which are suitably selected from the group of metals consisting of Pt, Pd, Ni, Ti, Fe, V, Cu, and alloys thereof, and hydrogen permeation nickel alloys. It is furthermore desirable that the insertion reaction side is in contact with colloidal polytetrafluorethylene and with an electrolyte capable of tolerating carbonation. Suitably, such an electrolyte is selected from the group consisting of aqueous sodium bicarbonate, phosphoric acid and solid electrolytes, such as Nation®.
There is also provided a method of generating electricity in a fuel cell as described generally and in any of the specific embodiments described above. This method comprises the sequential steps of: a. absorbing hydrogen from a source thereof on the absorption side of the atomic hydrogen transmissive membrane, b. passing hydrogen in atomic form, through the membrane to the opposite insertion reaction side of this membrane, c. providing a carbon compound to this insertion reaction side, d. allowing the direct electrochemical oxidation reaction of the carbon compound on the insertion reaction side to give an electrochemical oxidation product, 4 e. chemically reacting this product with the hydrogen passed through the membrane to give a reduction reaction product, f. further electrochemically oxidizing this reduction reaction products of step (e) to provide carbon dioxide, as the principal product of the complete electrochemical oxidation of the carbon compound; and g. reducing air oxygen to air at the cathode, and drawing electricity generated thereby in said fuel cell from the cathode and anode thereof.
In this process the fuel may be a fossil fuel, such as gasoline, kerosene or gas oil. It may also be a C-1 to C-6 alkane, such as methane, ethane, propane or butane. It may also be a C-1 to C-6 alcoh. ' . such as methanol, ethanol, propanol or butanol. It may also be carbon monoxide (CO).
The hydrogen containing medium may be hydrogen gas, hydrogen containing gas or hydrogen containing vapor. Suitably, however the process includes a further step of supplying electrolytically formed hydrogen at the hydrogen absorbing surface of the membrane. It is preferred to supply hydrogen to the hydrogen absorbing membrane at a rate sufficient to establish a concentration gradient across said membrane which drives the hydrogen through it.
The chemistry of the process may be summarized as follows:
As in the known process of Hartner (US patent 3393098), molecular hydrogen, H2, is produced from the steam reforming reaction, CH4 + 2 H2O → CO2 + 4 H2
This molecular hydrogen is absorbed at the steam reforming side of a hydrogen permeable membrane, 5 4 H2 → 8 H*
The occluded atomic hydrogen, H*, passes through the membrane to the fuel cell side, where it undergoes an electrochemical oxidation in accordance with the equation 8 H* → 8 H+ + 8 e
In the Hartner system the reaction at the cathode then proceeds as
2 O2 + 8 H+ + 8 e → 4 H2O
With an overall reaction: CH4 + 2 O2 - CO2 + 2 H2O
As a consequence each methane molecule produces 8 electrons, and the potential at zero current of this cell is 1 ,09 Volts.
In process of the present invention, two atomic hydrogens produced by steam reforming similarly passes through a membrane towards the fuel cell side,
0.25 CH4 + 0.5 H2O → 0.25 CO2 + H2 H2 → 2 H* However the fuel cell side is the anode, where the electrochemical oxidation of a carbonaceous compound takes place, this is signified by subsection (d) of the foregoing process summary,
CH4 + H2O → CO + 6 H+ + 6 e
According to Parsons and Vandernoot (Electroanal. Chem., 257 (1988) 9), this last reaction is undesirable since the carbon monoxide
(CO) poisons the electrode and hence, it is taught, that a viable direct electrochemical oxidation of a carbon based compound at room temperature is not possible.
The present invention provides a path around this problem: 6
As illustrated by step (e) above, the atomic hydrogen (H*) chemically reacts with the carbon monoxide adsorbed on the anode and transforms it into formaldehyde which then desorbs from the anode:
2 H* + CO → H2C = O 5 Thereafter, equally at the anode, in accordance with step (f) the formaldehyde is oxidized in accordance with the following equation: H2C = O + H2O → C02 + 4 H+ + 4 e Hence, the entire procedure in accordance with the addition of the reaction creating the atomic hydrogen and the reaction utilizing it on the to fuel cell side can be summarized as:
1 .25 CH4 + 2 H20 → C02 + 10 H+ + 10 e In the present system the reaction at the cathode is then
2.5 O2 + 10 H+ + 10 e → 5 H2O With the overall reaction, I5 1.25 CH4 + 2.5 O2 → 1.25 CO2 + 2.5 H2O
For comparison purposes, it will therefore be seen that both in Hartner 's process and in the present process, each methane molecule will produce 8 electrons. However, the theoretical potential of the present process would be 1.32 Volts against 1 ,09 Volts from Hartner 's. 0 Furthermore, in Hartner 's process all the current will be limited to the hydrogen permeation current, J,
J = D C0 / F L2 Where D is the membrane hydrogen diffusion coefficient, C0 is the hydrogen concentration at the steam reformed side, F is the Faraday 25 constant (96500 C/mol) and L is the thickness of the membrane. This equation implies a certain time, proportional to L2 / D, for the atomic hydrogen to travel through the membrane. In the present process one uses only two atomic hydrogen atoms per methane molecule electrochemically oxidized. Therefore, in principle the present process 0 will produce four times more current than Hartner 's and at higher potential. This happens because reactions (d), (e) and (f) will not occur in Hartner 's process and indeed in view of the quotation from Parsons and 7
Vandernoot (supra), no one reading Hartner 's disclosure would be led to attempt these reactions.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation of a non-poisoning fuel cell of the present invention.
Figure 2 is an schematic cross view of the non-poisoning anode. Figure 3 is a diagrammatic representation of the chemical and electrochemical processes occurring at the inside of the anode of figure 1 .
Figure 4 is a schematic diagram showing the details of a compact electrodes test fuel cell, together with an ampermeter used to test its operation. Figure 5, is a cyclic voltammetry of a palladium wire electrode, with no initially occluded hydrogen in NaOH 0.5 M.
Figure 6, is a cyclic voltammetry of a palladium wire electrode of Figure 5, deliberately loaded with hydrogen, in NaOH 0.5 M.
Figure 7, is a cyclic voltammetry of a palladium wire electrode of Figure 6, without occluded hydrogen in an aqueous 0.26 M NaHCOO and 0.24 M NaOH.
Figure 8, is a cyclic voltammetry of a palladium wire electrode of Figure 7 after 50 Coulombs of hydrogen were deliberately occluded .
Figure 9 shows the comparison between different current transitories obtained when a + 300 mV (SCE) potential pulse is applied on: 2.1 ) electroxidation of 2 Coulombs of occluded hydrogen in 0.5 M NaOH. 2.2) electroxidation of formate (HCOO ) on a palladium wire without occluded hydrogen and 2.3) electroxidation of formate (HCOO ) on a palladium wire with 2 Coulombs of occluded hydrogen. Figure 10, is a cyclic voltammetry of a palladium wire electrode, without occluded hydrogen in an aqueous 0.5 M NaOH and 0.2 M methanol. 8
Figure 1 1 , is a cyclic voltammetry of a palladium wire electrode of Figure 10, with 50 C of occluded hydrogen.
Figures 1 2 through 1 3 show current (I in milliamps) transitories (t in minutes) for different fuels in the compact electrodes fuel cell described in Figure 4.
Figure 1 2, 0.2 molar methanol and a saturated bicarbonate solution on palladium loaded with hydrogen.
Figure 1 3, 0.2 molar ethanol and a saturated bicarbonate solution on palladium loaded with hydrogen. Figure 14, 0.2 molar sucrose and a saturated bicarbonate solution on palladium loaded with hydrogen.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 is an schematic representation of the fuel cell arrangement of the present invention. This comprises a cathode 1 provided with oxygen or air input means 2 and water output means 3. The cell further comprises a non-poisoning anode 4, which comprises a net of capillaries 5, surrounded by a hydrogen supply line 6, originating in the catalytic steam reformer 7. The cell has a primary carbonaceous fuel input means 8 and a carbon dioxide output means 9. The electrolyte 10 is sandwiched between cathode 1 and anode 4. Hydrogen may be supplied by any source of hydrogen, however, it has been found useful to utilize a catalytic steam reformer 7 which is provided with a hydrogen source fuel through conduit 1 1 and carbon dioxide generated in said reformed exits through exit port 1 2. Alternatively the hydrogen may be electrolytically generated. The electricity generated by the system is taken off via cathode conduit 13 and anode conduit 14.
In Figure 2, a transverse view of the non-poisoning anode 4 is diagrammatically illustrated. The first face of the anode is a fluid permeable face 1 5, the body of the anode itself is made of a net of low thickness tubes or capillaries 5 made of a hydrogen permeation nickel 9 alloy or the like. This providesa holed structure to enable the molecular hydrogen to go into the third face 16 and diffuses through the tube wall 17 to the second face 18 of the anode. The outside of the tubes can be coated with platinum, palladium or similarly active particles 19 and with polytetrafluorethylene particles 20 or the like. The spaces between tubes act as meniscus areas . The hydrogen which passes through the capillaries 5 of the anode can react at the outside of the tubes or be ad/absorbed by the electrocatalytic particles 19 to react at their surfaces. In place of using a net of tubes or capillaries, there may be utilized a flat screen made of a porous hydrogen storing material such as nickel alloys or the like. Since the hydrogen goes into the anode material through its side, however, in the later case hydrogen diffusion will be less than in the net of tubes or capillaries.
In the operation of the fuel cell illustrated in Figure 1 , the electrolyte can be , for example, sodium bicarbonate, phosphoric acid or a room temperature solid electrolyte. Hydrogen from an appropriate source is continuously pumped into the net of capillaries 5 of the anode 4 , to keep the outside of the capillaries and/or the electrocatalytic particles 19 saturated with it. Although hydrogen is not used up in the subsequent electrochemical reactions, the hydrogen that does not reacts with the poisons, will electrochemically oxidize to protons, so a continuous hydrogen feed is needed. Air or a similar source of oxygen is then supplied, via conduit 2, to cathode 1 which should, preferably, be made of the state of the art gas diffusion porous electrode, and simultaneously therewith the primary fuel which can be in gaseous or liquid form, is applied through conduit 8 to anode 4. The potential in the cell generated in accordance with the equations set forth above are then taken off from the anode via conduit 14 and the cathode via conduit 13.
At the right hand side of the figure, a carbonaceous fuel indicated by methane, CH4 electrochemically reacts with hydroxyl moieties, OH, 10 formed from the water discharge, on the electrode surface yielding carbon monoxide, C = O, which would normally poison the anode at room temperatures. The reaction of the occluded hydrogen with the carbon monoxide is illustrated in the left hand and central portion of the figure, yielding formaldehyde, H2C = O (bottom center) which, leaves the surface to suffer an electrochemical oxidation with water, H2O, at the electric field to forms carbon dioxide, CO2, which is finally ejected toward the electrolyte.
I I
EXAMPLES Cyclic Voltammetry Experiments
Certain experiments have been conducted which are set forth bellow to determine the effect of prior occlusion of hydrogen or the absence thereof in palladium wire in certain chemical environment.
Control experiments 1 and 2 and Examples 1 , 2 , 3, 4 and 5 were performed in a conventional three electrode electrochemical cell, with a palladium wire as a working electrode, platinum as a counter electrode and a Saturated Calomel Electrode (SCE = 242 mV vs. Normal Hydrogen Electrode) as a reference. Cyclic voltammetry consists in measuring the current that floes through the working electrode, while a continuous positive and negative voltage ramps are applied on it. This is done by a potentiostat, and in this experiments, a voltage speed of 50 mV/s was used.
Also, voltage pulse experiments, going from open circuit potential to + 300 mV (SCE) in the different solutions used, were performed on palladium as a working electrode. This experiments consists in measuring the current that suffers the working electrode, when different potentials are applied on the working electrode, by a potentiostat. As a consequence, a current against time plot ( a transitory) is obtained. . In all of the following experiments, the amount of hydrogen is expressed by the equation:
Q = nF Wherein Q is the electric charge in Coulombs (C) ; n is the number of moles of hydrogen; and F is the Faraday constant (96500 C/mol) . 12
Control 1 Palladium Wire Electrode without Initially Occluded Hvdroαen
Figure 5 is a cyclic voltammetry of a palladium wire electrode, with no initially occluded hydrogen in NaOH 0.5 M. It shows the formation of palladium oxide pick (a),
Pd + 2 OH' → PdO + H2O + 2 e" followed by its reduction peak (b),
PdO τ H20 + 2 e' → Pd + 2 OH¬ Then the hydrogen ad/absorption zone (c),
2 H2O + 2 e" → 2 Had + 2 OH
Had = H
And the oxidation of the adsorbed hydrogen (d),
Hβd + OH" → H2O + e"
Control 2 Hartner (US patent 3393098) Process Example Figure 6 shows the cyclic voltammetry of the palladium electrode of Control 1 after initial occlusion of 50 C of hydrogen in the metal. Between 0 and + 300 mV (SCE), there is an oxidation wave diminishing in each potential cycle, which is due to hydrogen, coming from the inside of the electrode, and undergoes an electrochemical oxidation.
(a) is the main occluded hydrogen oxidation peak; H* + OH" → H2O + e"
(b) is the formation of palladium oxide plus the oxidation of occluded hydrogen; and (c) is the reduction of palladium oxide plus the oxidation of occluded hydrogen as well. 13 Example 1
Electroxichemical Oxidation of Formate HCOO' (Poisoning Effect
Example) Figure 7 is a cyclic voltammetry of the palladium electrode of Control 1 , without occluded hydrogen in an aqueous 0.26 M NaHCOO + 0.24 M NaOH.
Peak (a) is due to the formate oxidation to CO2. The current increases with potential. In this process CO is being generated, it strongly adsorbs on the electrode surface and poisons it. The current no longer increases and falls to almost zero, generating peak (a), HCOO + OH → CO2 + H2O + 2 e' HCOO → CO + OH At (b), palladium oxide is formed and the strongly adsorbed CO is also oxidized,
CO + 2 OH → CO2 + H2O + 2 e"
Later, in the back potential ramp and after the complete reduction of the palladium oxide formed, the current increases because a new and clean palladium surface oxidizes the formate in solution to CO2 again, as in the peak (a), forming peak (c) .
Example 2 The Process of the Present Invention Figure 8 is a cyclic voltammetry of the palladium wire of Example 1 , after 50 C of hydrogen were deliberately occluded. The current continuosly increases with the potential, the peak (a) (observed in Figure 7) has disappeared, because the non-poisoning reaction, already described is taking place,
HCOO → CO + OH CO + 2 H * → H2CO
H2CO + 2 OH → CO2 + H2O + 2 e 14
This means that if hydrogen is initially occluded in the metal, the poisoning phenomenon does not occur.
Comparison between different Current Transitories Figure 9 shows the comparison between different current transitories obtained when a + 300 mV (SCE) potential pulse is applied on the following experiments:
Control 2 Test: Hartner (US patent 3393098) Process Example: Curve 2.1 ) 2 C of occluded hydrogen in palladium (Q = 1 .5 C).
Example 1 Test: Electroxichemical Oxidation of Formate HCOO (Poisoning Effect Sample): Curve 2.2) HCOO' on hydrogen free palladium (Q = 0 C).
Example 2 Test: The Process of the Present Invention: Curve 2.3) HCOO on palladium with 2 C of occluded hydrogen (Q = 3.2 C) .
The three curves in this figure are interpreted as follows: In cm ι : 2.2, Example 1 there is no oxidation of formate. Curve 2.3, illustrating the present process shows that on Pd/H, 2 C, the formate oxidation charge, doubles that of the oxidation of hydrogen alone, as shown on curve 2.1 , which illustrate Hartner 's process. This means that formate is being oxidized with the assistance of the occluded hydrogen, which is the essence of the present process.
Example 3 Electroxichemical Oxidation of Methanol (Poisoning Effect Example) Figure 10 is a cyclic voltammetry of the palladium electrode of Control 1 , without occluded hydrogen in an aqueous 0.2 M CH3OH (methanol) + 0.5 M NaOH. 15
Peak (a) is due to the methanol oxidation to CO2. The current increases with potential. As in example 2, in this process CO is being generated, it strongly adsorbs on the electrode surface and poisons it. The current no longer increases and falls to almost zero, generating peak
(a),
CH3OH + H2O → CO2 + 6 H+ + 6 e CH3OH → CO + 4 H+ + 4 e At (b), palladium oxide is formed and the strongly adsorbed CO is άι >j oxidized,
CO + 2 OH → CO2 + H2O + 2 e
Later, in the back potential ramp and after the complete reduction of the palladium oxide formed, the current increases because a new and clean palladium surface oxidizes the methanol in solution to CO2 again, as in the peak (a), forming peak (c).
Example 4 The Process of the Present Invention with methanol as a fuel Figure 1 1 is a cyclic voltammetry of the palladium wire of Example 3, after 50 C of hydrogen were deliberately occluded. The current continuosly increases with the potential, the peak (a) (observed in Figure 10) has disappeared, because the non-poisoning reaction, is taking place,
CH3OH → CO + 4 H+ + 4 e CO + 2 H* → H2CO
H2CO + 2 OH " → CO2 + H2O + 2 e However, as the hydrogen is consumed at each cycle, peak a is observed again. This observation corroborate what was observed for formate (Figure 8).
Since the same kind of poisoning is observed in the electrochemical oxidation of formate and methanol. It can be concluded 16 that the non-poisoning phenomenon is general and it can be applied to any carbonaceous electrochemical oxidation.
Compact Electrodes Fuel Cell Test
There is further disclosed herein at Figure 4, an apparatus that simulate a fuel cell, for carrying out test experiments which are set forth in the examples 5 through 7 (below), regarding to the process of the present invention. This apparatus comprises a two-part cell having an anode sector 21 and a cathode sector 22. The cathode sector 22 is further provided with oxygen input means 23. The two sectors are separated by a sintered glass barrier 24 permeable to ion flow. An anode of palladium 25 is provided in sector 21 and a platinum cathode 26 is provided in sector 22. An ammeter 27 is connected to anode 25 via conduit 28 and to cathode 26 via conduit 29.
A 1 cm2 area palladium electrode 25 was occluded with hydrogen up to 1 50 C, at constant current, in a two electrodes electrochemical cell, using perchloric acid 0.5 M as electrolyte. Then the palladium electrode was transferred to the compact electrode fuel cell of Figure 4, where, as the non-poisoning effect of the occluded hydrogen is taking place, an spontaneous flow of current is expected and measured by the ammeter. This experiment were performed at room temperature.
Examples 5. 6 and 7 The Process of the Present Invention
In this experiment, methanol was used as a fuel in the compartment 21 of the compact electrodes fuel cell. It is well know that the poisoning effect happens during the first few minutes of operation, i.e. 1 5. In Figure 12 it is seen that the non-poisoning fuel cell is burning methanol and producing a current between 0.5 and 0.6 mA during 60 in. Which is only possible if the poisoning is terminated. Correspondingly, Figure 1 3 shows the cold burning of ethanol, which is 17 producing a current of 0.6 mA during 90 min. Going to a more complex fuel, in Figure 14 shows the cold burning of sucrose, which is producing a constant current of 0.4 mA during 100 min. All of these results demonstrate that a room temperature direct carbonaceous fuel feed fuel cell is viable.

Claims

18Claims
1. A fuel cell of the type that uses, as a fuel, a carbon compounds which undergoes electroxidation in said fuel cell, said cell comprising: a cathode, an electrolyte, and an anode, said anode comprising a first face that is fluid permeable and a second face in contact with said electrolyte, said second face comprising an atomic hydrogen transmissive membrane made of an electrocatalytic metallic element which stores and diffuses hydrogen in atomic form, said membrane having an absorption side and an opposite insertion reaction side.
2. The cell of claim 1 wherein the insertion reaction side comprises electrocatalytic particles.
3. The cell of claim 2 wherein the electrocatalytic particles are selected from the group of metals consisting of Pt, Pd, Ni, Ti, Fe, V, Cu, and the alloys thereof, and hydrogen occluding alloys of Ni.
4. The cell of claim 1 wherein the membrane material is selected from the group of metals consisting of Pd, Ni, Ti, Fe, V, Ta, Cu, and the alloys and mixtures thereof.
5. The cell of claim 1 wherein the insertion reaction side is in contact with an electrolyte capable of tolerating carbonation.
6. The cell of claim 5 wherein the insertion reaction side is in contact with an electrolyte selected from the group consisting of aqueous sodium bicarbonate and phosphoric acid.
7. The cell of claim 1 wherein the insertion reaction side is in 19 contact with colloidal polytetrafluorethylene.
8. A method of generating electricity in a fuel cell of any of claims 1 -7 comprising the steps of: a. absorbing a hydrogen containing medium on the absorption side of said atomic hydrogen transmissive membrane, b. passing hydrogen in atomic form, through the membrane to said opposite insertion reaction side thereof, c. providing a carbon compound to said insertion reaction side, d. allowing the direct electroxidation reaction of said carbon compound on the insertion reaction side to give an electroxidation product, e. chemically reacting the said electroxidation reaction product of the said carbon compound, with the hydrogen passed through the membrane to give a reduction reaction product, f. further electroxidizing said reduction reaction product of step
(e) to provide carbon dioxide, as the principal product of the complete electrochemical oxidation of the said carbon compound; and g. reducing oxygen to water at the cathode and drawing electricity generated thereby in said fuel cell from the cathode and anode thereof.
9. The process of claim 8 wherein the fuel is a fossil fuel.
10. The process of claim 9 wherein the fuel is selected from the group consisting of gasoline and gas oil.
1 1 . The process of claim 8 wherein the fuel is selected from the group consisting of C-1 to C-6 alcohols.
12. The process of claim 8 wherein the fuel is selected from the group consisting of C-1 to C-6 alkanes. 20
13. The process of claim 8 wherein the fuel is selected from the group consisting of C-2 to C-6 alkenes.
14. The process of claim 8 wherein the fuel is selected from the group consisting of C-2 to C-6 alkines.
15. The process of claim 2 wherein the fuel is Carbon monoxide.
16. The process of claim 8 wherein the hydrogen containing medium is selected from the group consisting of hydrogen gas, hydrogen containing gas and hydrogen containing vapor.
17. The process of Claim 8 comprising the additional step of electrolytically forming hydrogen at the hydrogen absorbing surface of the membrane.
18. The process of Claim 8 comprising supplying hydrogen to the hydrogen absorbing membrane at a rate sufficient to establish a concentration gradient across said membrane which drives the hydrogen there through.
PCT/US1998/007373 1998-04-08 1998-04-08 Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels WO1999053560A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/US1998/007373 WO1999053560A1 (en) 1998-04-08 1998-04-08 Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels
AU71126/98A AU7112698A (en) 1998-04-08 1998-04-08 Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1998/007373 WO1999053560A1 (en) 1998-04-08 1998-04-08 Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels

Publications (1)

Publication Number Publication Date
WO1999053560A1 true WO1999053560A1 (en) 1999-10-21

Family

ID=22266827

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/007373 WO1999053560A1 (en) 1998-04-08 1998-04-08 Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels

Country Status (2)

Country Link
AU (1) AU7112698A (en)
WO (1) WO1999053560A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7289826B1 (en) 2002-04-16 2007-10-30 Faulkner Interstices, Llc Method and apparatus for beam selection in a smart antenna system
US7349721B2 (en) 2002-04-16 2008-03-25 Faulkner Interstices, Llc System and apparatus for collecting information for use in a smart antenna system
US7418271B2 (en) 2002-04-16 2008-08-26 Faulkner Interstices Llc Smart antenna apparatus
US7463906B2 (en) 2002-04-16 2008-12-09 Faulkner Interstices Llc Method and apparatus for collecting information for use in a smart antenna system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1403195A (en) * 1963-06-20 1965-06-18 Tokyo Shibaura Electric Co Fuel cells
FR1417112A (en) * 1962-08-04 1965-11-12 Siemens Ag Process for the electrochemical transformation of dissolved, liquid or gaseous compounds containing hydrogen
US3337369A (en) * 1960-09-29 1967-08-22 Leesona Corp Non-porous diffusion membrane fuel cell
US3470026A (en) * 1965-03-03 1969-09-30 Prototech Inc Method of operating fuel cell with carbon-containing fuel
GB1449233A (en) * 1973-10-31 1976-09-15 Exxon Research Engineering Co Buffer electrolyte fuel cell with low cost electrodes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3337369A (en) * 1960-09-29 1967-08-22 Leesona Corp Non-porous diffusion membrane fuel cell
FR1417112A (en) * 1962-08-04 1965-11-12 Siemens Ag Process for the electrochemical transformation of dissolved, liquid or gaseous compounds containing hydrogen
FR1403195A (en) * 1963-06-20 1965-06-18 Tokyo Shibaura Electric Co Fuel cells
US3470026A (en) * 1965-03-03 1969-09-30 Prototech Inc Method of operating fuel cell with carbon-containing fuel
GB1449233A (en) * 1973-10-31 1976-09-15 Exxon Research Engineering Co Buffer electrolyte fuel cell with low cost electrodes

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7289826B1 (en) 2002-04-16 2007-10-30 Faulkner Interstices, Llc Method and apparatus for beam selection in a smart antenna system
US7349721B2 (en) 2002-04-16 2008-03-25 Faulkner Interstices, Llc System and apparatus for collecting information for use in a smart antenna system
US7418271B2 (en) 2002-04-16 2008-08-26 Faulkner Interstices Llc Smart antenna apparatus
US7444157B2 (en) 2002-04-16 2008-10-28 Faulkner Interstices Llc Method and apparatus for beam selection in a smart antenna system
US7463906B2 (en) 2002-04-16 2008-12-09 Faulkner Interstices Llc Method and apparatus for collecting information for use in a smart antenna system

Also Published As

Publication number Publication date
AU7112698A (en) 1999-11-01

Similar Documents

Publication Publication Date Title
US6245214B1 (en) Electro-catalytic oxidation (ECO) device to remove CO from reformate for fuel cell application
KR100476632B1 (en) Novel alkaline fuel cell
US6613471B2 (en) Active material for fuel cell anodes incorporating an additive for precharging/activation thereof
US6890419B2 (en) Electrolytic production of hydrogen
US8048548B2 (en) Electrocatalyst for alcohol oxidation at fuel cell anodes
US7157166B2 (en) Ammonia fuel cell
US20060292407A1 (en) Microfluidic fuel cell system and method for portable energy applications
JP3328993B2 (en) Hydrogen generation method
JP4779446B2 (en) Catalyst regeneration method, hydrogen generator and fuel cell system
JP3360349B2 (en) Fuel cell
WO2002027840A1 (en) Fuel cell using oxygen carrying liquid
US5804325A (en) Non poisoning fuel cell and method
JP4677438B2 (en) Fuel composition and fuel cell using the same
JP2004311159A (en) Method and device for manufacturing high pressure hydrogen and fuel cell electric vehicle
WO1999053560A1 (en) Nonpoisoning fuel cell and methods of operating the same with carbonaceous fuels
JP4278132B2 (en) Highly efficient hydrogen production method and apparatus
CN115074768A (en) Electrochemical reaction device, method for reducing carbon dioxide, and method for producing carbon compound
CN1330033C (en) Fuel cell system and fuel supply apparatus
JPH0927327A (en) Fuel cell electrode and manufacture thereof
KR101030045B1 (en) Reformer for fuel cell system and fuel cell system comprising the same
JP2005298307A (en) Fuel reformer for fuel cell and fuel reforming method
CN115939427A (en) Integrated alkaline regenerated methanol fuel cell
JP2023140042A (en) Electrolytic apparatus and driving method of electrolytic apparatus
JP2001283890A (en) Fuel gas generating system of fuel cell
JP2004099369A (en) Fuel reforming apparatus

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM GW HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: KR

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA

122 Ep: pct application non-entry in european phase