WO2006063992A2

WO2006063992A2 - Catalysts based on transition metals, their preparation and use and fuel cells containing them

Info

Publication number: WO2006063992A2
Application number: PCT/EP2005/056728
Authority: WO
Inventors: Pierluigi Barbaro; Paolo Bert; Claudio Bianchini; Giuliano Giambastiani; Simonetta Moneti; Adriana Scaffidi; Alessandro Tampucci; Francesco Vizza
Original assignee: Acta S.P.A.
Priority date: 2004-12-13
Filing date: 2005-12-13
Publication date: 2006-06-22
Also published as: WO2006063992A3; WO2006063992A8; ITFI20040260A1

Abstract

Copolymer resin obtained by the condensation of 4 - { l - [ ( 2, 4 -dinitrophenyl) -hydrozone] -ethyl} -benzene -1, 3 -diol} with phenol and furfural in the presence of an acid or basic catalyst in water / ethanol mixtures of temperatures between 20 and 1500C, having a molecular weight between 1000 and 50.000. Anodic or cathodic catalysts for fuel cells obtained by the treatment of metal complexes and such a copolymeric resin, their preparation processes and electrodes for fuel cells comprising there catalysts .

Description

CATALYSTS BASED ON TRANSITION METALS, THEIR PREPARATION AND USE AND FUEL CELLS CONTAINING THEM. Field of invention

The present invention concerns catalysts for both anode and cathodes electrodes for fuel cells. State of the art

A fuel cell is a device capable of transforming directly chemical energy contained in a molecule into electrical energy.

The process of production of electrical power in a fuel cell occurs with the evolution of heat, water, and in certain cases of CO₂, depending on the fuel, which can be either gaseous or a compound containing atomic hydrogen. No matter what the fuel is, every cell employs oxygen, pure or atmospheric, as a co-reagent which is then turned into water.

A modern fuel cells with polymeric electrolyte working with pure or combined hydrogen is made up of two electrodes of porous and conductive material, separated by a polymeric membrane permeable to ions, called electrolyte (Figure 1 ). Hydrogen-fed fuel cells containing a polymeric membrane as solid electrolyte are known with the acronym PEMFC (Polymer Electrolyte Membrane Fuel Cell), whereas fuel cells fed with aqueous solutions of compounds that carry combined hydrogen, generally alcohols, are known with the acronym DFC, which stands for Direct Fuel Cell. The most diffused DFC makes use of methanol (CH₃OH), and is known as DMFC (Direct Methanol Fuel Cell). A common DMFC of the state of the art resembles a PEMFC in its configuration and working. In DMFCs indeed the electrolyte consists of a polymeric membrane which is either proton or anion exchange membrane, and the electrocatalysts contain platinum or platinum alloys with other metals. When the electrolyte is an anion exchange membrane, the hydroxide ion generated at the cathode passes through the membrane to the anode thus closing the circuit. In fuel cells, both the anodic and cathodic reactions occur on catalysts (or electrocatalysts) which consist either of metallic sheets, or of highly dispersed metallic nano-particles (usually 2-50 nanometers, 10^~9 m, large), supported on a porous and conductive material (for instance carbon black). It is an accepted fact that the activity of a catalyst and especially a bimetallic or trimetallic catalyst depends upon both electronic and structural factors. Structural factors are influenced by both the method of synthesis and the nature of the metals employed with platinum.

In the international patent application (Platinum-free electrocatalysts materials, WO 2004/036674, PCT/EP 2003/006592) it is reported that a polymer template formed by the condensation of a 1 ,3- diol containing a coordinating nitrogen, with phenol or phenol 3,5-substituted and formaldehyde or paraformaldehyde is able to coordinate metal salts excluding platinum, but preferably containing iron, cobalt and or nickel that give adducts that once reduced with hydrogen or other reducing agents or pyrolised under inert atmosphere at temperatures above 500°C, produce catalytic materials for anode and cathode electrodes for fuel cells of the type PEMFC, AFC, DFC, DMFC, DEFC and in general DAFC. In the same patent it is reported that alcohols like methanol, ethanol and ethylene glycol are oxidised completely to CO₂ at the anode of "self-breathing" cells at room temperature.

Italian patent application No. FI20040000162 describes novel cathode electrocatalysts obtained by the complexation of cobalt salts alone or in combination with other metals, from templating polymers described in the international patent application N.° WO 2004/036674, followed by chemical reduction using state of the art methodology.

Catalysts containing nanometric or sub nanometric (10^~9 m) metal particles are described in the Italian patent application No. FI20040000154 which refers to the preparation using templating polymers described in international patent application No. WO 2004/036674 of anodic electrocatalysts containing Pt and its alloys with other metals used in fuel cells fed with hydrogen or compounds containing hydrogen.

Nayak et al. describe {Polymer Int. 1994, 34, 319-326 and the cited references 18-28; Polymer Int. 1992, 29, 103-106) the synthesis and characterisation of numerous compounds called copolymeric resins obtained by the condensation, in basic or acidic conditions, of acetophenone (hydroxy or aminoacetophenone) with formaldehyde/furfural and hydroxyaromatic compounds or substituted aromatic acids (chloro, amino, nitro) like the synthesis of various copolymeric resins obtained by condensation of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}-benzene-1 .3-diol} with a series of hydroxyaromatic compounds or substituted aromatic acids (chloro, amino, nitro) and formaldehyde or furfural. All of the resins described are used exclusively as biologically active agents (antibacterial and antifungal) or as ion exchange resins.

In light of the state of the art and considering the enormous importance economically of fuel cells and their multiple possible applications it is clear the importance of making available new efficient catalysts and the simplification of the processes used to produce them. Summary of the invention This invention relates to the need for new anodic and cathodic catalysts for fuel cells which contain low levels of transition metals in the form of sub nanometric and nanometric particles and simplified processes for their production. The use of known products to make catalysts for fuel cells is also described.

Description of the figures

Fig. 1 - Simplified scheme of a fuel cell operating with a catalyst of the invention.

Fig. 2 - Histogram showing the particle size distribution in a Fe₃₀-Co₃₀-Ni₄₀ catalyst containing 2.1 wt% overall metal loading with respect to the metal/support (Vulcan XC-72) catalytic system, realised as in method 4. Fig. 3 - Histogram showing the particle size distribution in a Pt catalyst (1 .2 wt% metal loading) with respect to the metal/support (Vulcan XC-72) catalytic system obtained using the method described in 5.

Fig. 4 - Histogram showing the particle size distribution in a Ni catalyst (1 .5 wt% metal loading) with respect to the metal/support (Vulcan XC-72) catalytic system obtained using the method described in 6. Fig. 5 - Polarisation curve of a PEMFC {Nation⁹ '-1 12, H₂SO₄ 1 N) comprised of an anode catalysed with 0.10 mg Pt₅₀-Ru₅₀ZCm² (2.0% metal/C) and a cathode catalysed with 0.10 mg Ni/cm² (1.0% metal/C) at 60 °C, with pure H₂ (1 bar) (curve a) or contaminated with 200 ppm of CO (curve b).

Fig. 6 - Polarisation curve of a DMFC (Nation^®- 1 12, H₂SO₄ 1 N) comprised of an anode catalysed with 0.20 mg Pt₅₀-Ru₅₀ /cm² (2% metal/C) and a cathode catalysed with 0.10 mg Ni/cm² (1.0% metal/C) at. 65 °C, fed with an aqueous solution of MeOH at 15% (v:v).

Fig. 7 - Polarisation curve of a DEFC Iβelemion AMW, K₂CO₃ 1 N) comprised of an anode catalysed with 0.10 mg Fe₃₀-Co₃₀-Ni₄₀ /cm² (2% metal/C) and a cathode catalysed with 0.10 mg

Co/cm² (1 .5% metal/C) at 25 ⁰C, fed with an aqueous solution of EtOH at 10% (v:v).

Fig. 8 - Variation of current density with time at constant potential (0.5 V) for a mono-planar cell comprised of an anode with catalyst Fe₃₀-Co₃₀-Ni₄₀ (0.20 mg/cm²) and a cathode of Co (0.20 mg/cm²) (30 °C; ethanol 10% w).

Detailed description of the invention

This invention refers to a polymeric resin of formula (A) obtained from the condensation of 4-{1 -

[(2,4-dinitrophenyl)-hydrazone]-ethyl}-benzene-1 ,3-diol} with phenol and furfural, in the presence of an acid or basic catalyst in a water/alcohol mixture at a temperature of between 20 and 150°C. The average molecular weight is between 1 .000 and 50.000. In this compound x can vary between 1 and 2, n can vary between 1 and 3 and y can vary between 2 and 120.

In another possible embodiment, this invention refers to metal complexes formed from the above resin and a transition metal salt alone or in combination with other salts or other metal compounds useful as catalysts to produce anodes and cathodes for fuel cells.

Transition metals are defined as preferably Fe, Ni, Ru, Co, Rh, Ir, Ni, Pt, Pd, Mo, Sn, La, V, Mn and

Cu, alone or in combination with other metals.

In another possible embodiment, this invention refers in particular to the embodiment of anodic and cathodic electrodes with catalysts containing iron, cobalt and nickel (anode) and with cobalt or nickel (cathode) for DFC type fuel cells that don't use precious metals and allow the use of fuels containing hydrogen including aldehydes, acids, hydrazine, metallic borohydrides in aqueous solution or alcohols up to 50 wt%.

In another possible embodiment, this invention refers to anodes and cathodes for DAFC type fuel cells that contain platinum only or in combination with other metals for example Fe, Ni, Ru, Co, Rh,

Ir, Ni, Pd, Mo, Sn, La, V, Mn and Cu, that allows the use of alcoholic fuels such as methanol, ethanol, ethylene glycol, or sugars like glucose and sorbitol, in aqueous solutions with concentrations up to 50 wt% using a quantity of platinum non superior to 0.30 mg/cm², preferably less than or equal to 0.20 mg/cm² and, more importantly allows the exploitation of all energy possible from a particular fuel converting it completely to CO₂. In another possible embodiment, this invention refers to anodes and cathodes for DFC type fuel cells that contain platinum only or in combination with other metals for example Fe, Ni, Ru, Co, Rh, Ir, Ni, Pd, Mo, Sn, La, V, Mn and Cu, that allows the use of alcoholic fuels such as methanol, ethanol, ethylene glycol, or sugars like glucose and sorbitol, in aqueous solutions with concentrations up to 50 wt% using a quantity of platinum non superior to 0.30 mg/cm², preferably less than or equal to 0.20 mg/cm²

This invention refers in particular to the embodiment of cathodes for fuel cells of DAFC and AFC type that contain cobalt or nickel only or with Cu that allow the use of fuels such as alcohols e.g. methanol, ethanol, ethylene glycol, or sugars glucose and sorbitol in aqueous solutions with concentrations up to 50 wt%. In another possible embodiment, this invention refers to cathodes for DAFC and AFC type fuel cells that contain platinum only or in combination with other metals for example Fe, Ni, Ru, Co, Rh, Ir, Ni, Pd, Mo, Sn, La, V, Mn and Cu, that allows the use of alcoholic fuels such as methanol, ethanol, ethylene glycol, or sugars like glucose and sorbitol, in aqueous solutions with concentrations up to 50 wt% using a quantity of platinum non superior to 0.30 mg/cm², preferably less than or equal to 0.20 mg/cm²

According to a further embodiment this invention refers to the use of metal complexes formed from a salt or transition metal compound alone or in combination with other salts or metal compounds and copolymeric resins obtained from the condensation of hydroxy or aminoacetophenones with formaldehyde or furfural and hydroxyl-aromatic compounds or substituted aromatic acids fchloro, amino, nitro) and also with o/m-alkyl benzoic acids, o/m/p-chloroaniline, o/m/p-toluene, chloroacetophenone, naphthol, bis-phenols, phenophthelein and hydroxyquinoline in the presence of either acid or basic catalysts in water/alcohol mixtures and at temperatures between 20 and 150 °C and an eventual molecular weight distribution between 1000 and 50000 for the preparation of anodic and cathodic catalysts for fuel cells. In addition, this invention refers to the use of metal complexes formed from a salt or transition metal compound alone or in combination with other salts or metal compounds and copolymeric resins obtained from the condensation of 4-{1 -[(2,4-dinitro-phenyl)-hydrazone]-ethyl}-benzene-1 ,3- diol} with a series of substituted hydroxyl or acidic aromatic compounds (chloro, amino, nitro) and also with o/m-alkyl benzoic acids, o/m/p-chloroaniline, o/m/b-toluene, chloroacetophenone, naphthol, bis-phenols, phenophthelein and hydroxyquinoline and formaldehyde or furfural in the presence of either acid or basic catalysts in water/alcohol mixtures and at temperatures between 20 and 150 °C and an eventual molecular weight distribution between 1000 e 50000 for the preparation of anodic and cathodic catalysts for fuel cells. The resins can be obtained from the condensation of hydroxy or aminoacetophenones with formaldehyde or furfural and hydroxy aromatic compounds or substituted aromatic acids fchloro, amino, nitro) and also with o/m alkyl benzoic acids, o/m/p-chloroaniline, o/m/p-toluene, chloroacetophenone, naphthol, bis-phenols, phenophthelein and hydroxyquinoline in the presence of either acid or basic catalysts in water/alcohol mixtures and at temperatures between 20 and 150 °C and a molecular weight distribution between 1000 and 50000.

In addition the resins may be obtained from the condensation of 4-{1 -[(2,4-dinitro-phenyl)- hydrazone]-ethyl}-benzene-1 ,3-diol} with a series of substituted hydroxyl or acidic aromatic compounds (chloro, amino, nitro) and also with o/m-alkyl benzoic acids, o/m/p-chloroaniline, o/m/p- toluene, chloroacetophenone, naphthol, bis-phenols, phenophthelein and hydroxyquinoline and formaldehyde or furfural in the presence of either acidic or basic catalysts in water/alcohol mixtures and at temperatures between 20 and 150 °C and an eventual molecular weight distribution between 1000 e 50000.

The hydroxyacetophenones above can have the formula (B) and the substituted aromatic compounds can have the formula (C).

R-_I, in the compound of formula (B) represents an O, N, N-NH₂, NHCONH₂ and R₂ and R₃ represent independently H and OH and R₄, R₅, R₆, R₇, Rs and Rg in the compound of formula (C) independently represent a group comprised of H, OH, ether, ammine, acid, nitro, halogen, aryl and alkyl groups both linear or branched, having from 1 to 15 carbon atoms possibly functionalised with OH, ketone, or joined in some way so as to form condensed or non-condensed cycles with the aromatic ring of group (C). In all cases there must be at least two C-H groups in the aromatic ring of group (C).

The 4-{1 -[(phenyl-2,4-disubstituted)-hydrazone]-alkyl}-benzene-1 ,3-diol is a compound of formula (D) and the substituted aromatic compound has the formula (C) as defined above.

R₁₀ can be one of the following group: H or a radical hydrocarbon having from 1 to 10 carbon atoms, possibly halogenated; Rn e Ri₂ independently represent an electron attracting group chosen from the following; hydrogen, halogen, acyl, ester, carboxylic acid, formyl, nitrile, sulfonic acid, aryl groups or alkyl groups linear or branched having 1 to 15 carbon atoms possibly functionalised with halogens or arranged in a way so as to form one or more condensed cycles with the phenyl ring and nitro groups.

Catalysts in which the said copolymeric resins are polymers represented by the formula (E) and

(F).

R, R₂, R₃, R₄ ,R₅₁R₆₁ R₇, R₈, R₉ are defined above.

In another possible embodiment, of this invention, the said copolymeric resins are polymers that may be represented by the formula (G) e (H).

(G) in which y can vary from 2 to 120, x can vary from 1 to 2, n can vary from 1 to 3 and R₄, R₅, R₆, R₇

,R₈ e Rg, Rio, R-11 e Ri₂ are defined above.

In particular the compounds of formula (B) and (C) or (D) and (C) incorporated in the polymeric resins are bridged by a group of formula CHR-i, where R, can be any aromatic ring or heteroatom or alkyl group linear or branched having from 1 to 15 carbon atoms possibly functionalised with alcoholic, aldehyde, ammine, nitro, acid and halogen groups to name but a few. The applicant has in fact surprisingly found that the metalized polymeric resins described above may be absorbed onto conductive supports typically amorphous carbon or highly porous graphite and once reduced with gaseous hydrogen or with other reducing agents, or pyrolised at temperatures above 500 °C, produces efficient catalytic materials for anodic and cathodic electrodes for fuel cells of the type PEMFC and DAFC (DMFC, DEFC).

The catalysts obtained by the applicant are characterised by a very high metal dispersion with particle dimensions from 0.3 to 10 nanometri (10^~9 m), with the major frequency of particle size between 0.3 and 1 nm.

In addition the same catalysts may be employed on non-conductive support materials such as porous organic oxides e.g. silica, alumina, magnesia, zirconia and ceria. Once purified and activated by state of the art methods they may be used for other applications other than in fuel cells. Another purpose of this invention refers to the method for the preparation of the resins described above. According to the invention the preparation of the templating copolymer resins described above uses methods 1 , 2 or 3. Method 1 uses water as solvent and a quantity of furfural or formaldehyde in double proportion as compared to that of the other two co-monomers. In methods 2 and 3 an excess of formaldehyde or furfural is used and water is used as the solvent. Method 1

A suspension in water (120 ml_) comprised of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}-benzene- 1 .3-diol} or resacetophenone (0.028. mol), a substituted phenol or a substituted benzoic acid (0.028 mol), p-formaldehyde or furfural (0.056 mol) and 40 ml_ of KOH (5%), is kept at reflux for 6- 12 h at 1 10°C. The solid that forms is filtered and washed thoroughly and then dried under vacuum at 60 °C to constant weight. Method 2

A suspension comprised of a 4-{1 -[(2, 4-dinitrophenyl)-hydrazone]-ethyl}-benzene-1 .3-diol}, (0.028 mol) or resacetophenone, a substituted phenol or a substituted benzoic acid (0.028 mol), formaldahyde or furfural (2.84 mol) and 13.6 ml_ of KOH (40%) is kept at reflux for 6-12 h at 1 10⁰C for 8-10 h. The solid that forms is filtered and washed thoroughly with cold water and then with hot water (50 ⁰C) to remove low molecular weight fractions and is then dried under vacuum at 60 °C to constant weight. Method 3 A suspension comprised of 4-{1 -[(2, 4-dinitrophenyl)-hydrazone]-ethyl}-benzene-1 .3-diol}, (0.028 mol) or resacetophenone a substituted phenol or a substituted benzoic acid (0.028 mol), formaldahyde or furan (2.84 mol) and 57 ml_ of HCI (2M), is kept at reflux at 11 O⁰C for 8-10 h. The solid that forms is filtered and washed thoroughly with cold water and then with hot water (50 °C) to remove low molecular weight fractions and is then dried under vacuum at 60 °C to constant weight. For the preparation of catalysts for use in anodes for fuel cells it is possible to use methods 4, 5 and 6 as follows below. Method 4

A mixture comprised of three compounds or salts, for example cobalt acetate tetrahydrate (Co(OAc)₂.4H₂0), nickel acetate tetrahydrate (Ni(OAc)₂4 H₂O) and iron acetate (Fe(OAc)₂) dissolved in water, is added to an aqueous suspension of one of the synthetic resins described in this patent as POLIMERS P1 , P2, P3 etc. The solid product that forms (from now on known as METALISED POLYMER) is filtered, washed with water and air dried. The dry solid is added to a suspension in acetone or another organic solvent of a porous conductive carbon based material (amorphous or graphite based), e.g. Vulcan XC-72 or activated carbon RDBA, to name a few. The resulting product is treated with a reducing agent of the state of the art (for example: NaBH₄ or NH₂NH₂), filtered, washed with water, dried and conserved under an inert atmosphere (N₂ or Ar).

Alternatively, the METALISED POLYMER once added to the porous conductive carbon based material, is isolated by evaporation of the solvent and then treated with a current of hydrogen gas at a temperature between 300 and 800 °C. For other uses apart from fuel cells, the METALISED POLYMER is reacted with a suspension of an activated porous metal oxide , like silica, alumina and ceria in acetone or another organic solvent. After stirring for a few hours, the material is filtered, washed with water, and dried; the metals complexed by the polymer and then supported are reduced by the same methods describe above. Method 5

A metal salt or compound, for example hexachloroplatinic acid (H₂PtCI₆) dissolved in water, is added to an aqueous suspension of a POLYMER. The solid product that forms is filtered, washed with water and air dried. The dry solid (METALISED POLYMER ) is added to a suspension in acetone or another organic solvent of a porous conductive carbon based material (amorphous or graphite based), e.g. Vulcan XC-72 or activated carbon RDBA, to name a few. The resulting product is treated with a reducing agent of the state of the art (for example: NaBH₄ or NH₂NH₂), filtered, washed with water, dried.

Alternatively, the METALISED POLYMER once added to the porous conductive carbon based material, is isolated by evaporation of the solvent and then treated with a current of hydrogen gas at a temperature between 300 and 800 °C. Alternatively, the METALLISED POLYMER once added to the porous conductive carbon based material in acetone, is isolated by evaporation of the solvent and then heated under a flow of nitrogen gas to 800 °C.

For other uses apart from fuel cells, the METALISED POLYMER is reacted with a suspension of an activated porous metal oxide , come silica, alumina and ceria in acetone or another organic solvent. After stirring for a few hours, the material is filtered, washed with water, and dried; the metals complexed by the polymer and then supported are reduced by the same methods describe above. Method 6

A metal salt or metal compound, for example nickel acetate tetrahydrate dissolved in water, alone or together with another transition metal, chosen preferably from Fe, Ru, Co, Rh, Ir, Pt, Pd, Mo, Sn, La, V, Mn, Cu, dissolved in water is added to an aqueous suspension of POLYMER. After a few hours the solid product that forms is filtered, washed with water and dried. This dried solid (METALISED POLYMER), is added to a acetone suspension of porous carbon like Vulcan XC-72 or activated carbon RDBA (to name a few). After stirring for a couple of hours a state of the art reducing agent e.g. NaBH₄ or NH₂NH₂ is added in excess. The solid product obtained is filtered, washed and dried.

Alternatively, the METALISED POLYMER once added to the porous conductive carbon based material, is isolated by evaporation of the solvent and then treated with a current of hydrogen gas at a temperature between 300 and 800 °C. Alternatively, the METALISED POLYMER once added to the porous conductive carbon based material in acetone, is isolated by evaporation of the solvent and then heated under a flow of nitrogen gas to 800 °C.

For other uses apart from fuel cells, the METALISED POLYMER is reacted with a suspension of an activated porous metal oxide, like silica, alumina and ceria in acetone or another organic solvent. After stirring for a few hours, the material is filtered, washed with water, and dried; the metals complexed by the polymer and then supported are reduced by the same methods describe above. Preparation of the anode Method (a)

The catalysts supported on conductive carbon prepared by methods 1 - 6 are suspended in a mixture of water/ethanol. To this vigorously stirred suspension is added PTFE (polytetrafluoroethylene) and the flocculent solid obtained is separated and spread on a conductive support like carbon paper, steel or nickel netting. These electrodes are then heated to 350 °C under a flow of inert gas (Ar, N₂). Method (b) The products obtained from the reaction of the metal salts or compounds with the POLYMER (METALISED POLYMER) are dissolved in a polar organic solvent like acetone or dimethylformamide. A portion of this solution is deposited on a disc of highly porous conductive material such as silver, nickel, ceramic powder (like Wc or MOc). These discs once prepared are dried and then treated with a reducing agent (for example, NaBH* or NH₂NH₂) or exposed to a flux of hydrogen gas at a temperature between 300 e 800 °C. For the preparation of catalysts for use in cathodes for fuel cells it is possible to use methods 7 and 8 as follows below. Method 7

A metal salt or metal compound, for example cobalt acetate tetrahydrate (Co(OAc)₂.4H₂0) dissolved in water, is added to an aqueous suspension of the POLIMERO. The solid product formed after stirring for an hour is filtered, washed with water and dried. This solid is added to a suspension of porous carbon like Vulcan XC-72 or activated carbon RDBA (to name a few) in acetone or dimethylformamide or another organic solvent. After stirring for a couple of hours the solvent is removed under reduced pressure and the solid obtained is heated to a temperature between. 500 and 900°C under an inert atmosphere (N₂ or Ar). Method 8

A metal salt or metal compound for example hexachloroplatinic acid (H₂PtCI₆) dissolved in water, and a metal salt, preferably nickel, cobalt, molybdenum, lanthanum, vanadium and manganese, dissolved in water are added to an aqueous suspension of the POLYMER. The solid product formed after a few hours, is filtered, washed and dried. This solid is added to a suspension of porous carbon like Vulcan XC-72 or activated carbon RDBA (to name a few) in acetone or dimethylformamide. After stirring for a few hours the solvent is eliminated by evaporation under reduced pressure and the residual solid is heated to a temperature between 500 and 900°C under an inert atmosphere (N₂, Ar). Preparation of the cathode: The catalytic material obtained with the methods described in 7 and 8 is suspended in a mixture of water/ethanol to which is added PTFE (polytetrafluoroethylene) and the flocculous solid that forms is separated and spread at room temperature on a support such as carbon paper or steel netting made hydrophobic by state of the art methods. The supported catalyst is then heated to a temperature between 300 and 350 °C under an inert atmosphere (N₂, Ar). The metallic composition of the catalysts has been determined by Inductively Coupled Plasma Atomic Emission Spetroscopy (ICP-AES) and verified by Energy Dispersive X-ray Spectrometry (EDXS).

The histograms shown in Figures 2-4, demonstrate the results of measurements made using Transmission Electron Microscopy (TEM) at high resolution, and show the distribution of the particle dimensions of the catalysts of this invention.

The highest frequency of the size distribution of the particles is no higher than 1 nm, and is clustered between 0.3 and 0.7 nm. The metal loading of the reduced metal-supported material can be varied from between 0.1 and 50% in weight with respect to the support. The metal particles of catalyst described in this invention are characterised by a very small quantity of atoms, no more than a dozen, which gives life to a structure capable of extraordinary reactivity in anodes and cathodes in various types of fuel cells containing solid electrolytes made of polymeric membranes either proton exchange (for example Nation^®) or anionic (for example Flemion^® of Asahi Glass or Morgane^® of Solvay). Experiments using Diffuse Reflectance Infrared Spectroscopy (DRIFT) have shown that the catalysts of the invention either individual metals or combinations of metals do not interact strongly with gaseous CO.

The anodes made with the catalysts of this invention are able to convert gaseous hydrogen (pure or reformed), metal borohydrides, hydrazine and hydroxylamine into electrons and protons. They are also able to convert a great variety of compounds containing oxygen and hydrogen atoms into electrons and CO₂. For example methanol, ethanol, ethylene glycol, acetaldehyde, formic acid, glucose and sorbitol to name but a few all at ambient temperature and pressure. In general the catalysts of the invention and the electrodes that they are contained in can be used to catalyse any fuel containing hydrogen even saturated hydrocarbons like methane (natural gas), ethane, propane and butane as well as gasoline and kerosene.

The cathodes made with the catalysts of this invention convert pure oxygen or that contained in air into water (when the electrolyte is a proton exchange membrane) or in hydroxide ions (OH^") (when the electrolyte is an anion exchange membrane). An anode of this invention in combination with a cathode of this invention or with a cathode for fuel cells of the state of the art and a cathode of this invention in combination with an anode of this invention or with any anode for fuel cells of the state of the art can be used to assemble fuel cells like that shown in Figure 1 .

The performance of mono-planar fuel cells with electrodes of this invention have been tested with a potensiostat/galvanostat (Princeton PARTSTAT 2273) under various experimental conditions. The cathodes and anodes of this invention exhibit properties and activity comparable with those described in the international patent application N.o WO 2004/036674 for analogous electrodes with cation and anion exchange membranes in fuel cells fed with hydrogen or direct alcohol. Figures 5-7 show examples of the polarisation curves for different combinations of anodes and cathodes. According to a particular embodiment this invention refers to the formation of anodic and cathodic electrodes catalysed preferably with iron, cobalt, nickel (anode) and with cobalt or nickel (cathode) for fuel cells of PEMFC and DAFC type. The invention will now be better illustrated with some specific examples.

Example 1

PREPARATION OF NOVEL POLYMER P1

A mixture of 2.45 g (0.026 mol) of phenol, 2.16 mL (0.026 mol) of 2-furfural and 20 mL of KOH (5%) is added to a suspension of 7 g (0.02 mol) of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}- benzene-1 ,3-diol in 60 mL of H₂O. The resulting suspension is kept at reflux for 6 h (1 10°C). The red solid that forms is collected by filtration and washed thoroughly with water (4 x100 mL) and water/acetone (1 :1 v:v) to remove the low molecular weight fraction. The solid product is then dried under vacume and at 60 °C to constant weight. Yield 7.2 g. Elemental analysis: C, 61 . 40; H, 5.01 ; N, 10.4 % (The analysis is in agreement with the polymer composition with x = 1 and n = 1 ). CaIc: C, 62.43; H, 5.08; N, 10.60 %.

FT-IR, (?/crrf¹): 3600-3120 (? OH); 3280 (? NH); 3100 (? CH aromatic); 2950 (? CH furf.);1650 (? CN); 1585 (? NH); 1520 (?_S.NO₂); 1515 (?_as.NO₂); 1330 @ OH); 830 (? C-NO₂ Ar.). UV-Vis: ?„_«, = 386 nm; shoulder at 433 nm (DMSO, 294 K). ¹H NMR (400.13 MHz, DMSO, 298 K): d = 2.2-2.4 (- CH₃-NC) 6.0 (CH, furf.); 6.7-7.1 (H, furf.) 6.8-7-4: 8.0-8.4 (H, phenol); 8.7-9.0 ( H, Ar.); 9.1 -9.2 (OH, Ar-) 1 1 .1 -11 .3 (OH, Ar-); 1 1 .5-1 1 .8 ( Ar, NH-N); ¹³C{¹ H} (100.62 MHz, DMSO, 298 K): d = 15.30- 115 ( CH₃-CN) 33.6-34.4 (CH furf.); 103.9-1 15.3 -(CH Ar); 1 16.3-1 17 .1 (m-phenol); 1 19.1 -120.2 Ip- phenol); 122.2-123-4 (C, furf.)-124.2-125.2 (C furf.) 131 .2-132.5 ( o-phenol); 132.9-134.6 (C furf.); 138.2 (C-NO₂); 158 (/-phenol); 160.3-161 .4 (HO-C, Ar). Example 2 PREPARATION OF POLYMER P2

Method a). To a suspension of 5 g (0.014 mol) of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}- benzene-1 ,3-diol in 100 ml_ of H₂O is added 1 .89 g (0.015 mol) of p-nitrophenol (Aldrich), 0.85 g (0.028 mol) of p-formaldehyde (Aldrich) and 30 ml_ of KOH (7 %). The resulting suspension is heated to reflux for 6 h at 110 °C. The red solid that forms is collected by filtration and washed thoroughly with water (4 x100 ml_) and then dried under at 60 °C to constant weight. Yield 5 g. Elemental analysis: C, 58. 40; H, 5.01 ; N, 1 1.4 % (The analysis is in agreement with the polymer composition with x = 1 and n = 1 ) CaIc: C, 58.18; H, 4.58; N, 10.60 %. FT-IR, (tom^"1): 3600-3120 (? OH); 3240 (? NH); 3100 (? CH aromatic); 2930 (? CH furf.);1640 (? CN); 1585 (? NH); 1510 (?_S.NO₂); 1510 (?_as NO₂); 1330 (d OH); 830 (? C-NO₂ arom.). UV-Vis: ?_M = 396 nm; shoulder a 443 nm (DMSO, 294 K). ¹H NMR (400.13 MHz, DMSO, 298 K): d = 2.4-2.8 (NCCH₃); 6.0 (CH, furf.); 6.7-7.1 (H, furf.);. 7.5-7.6 (CH, Ar.); 8.2-8.4 ^r-H); 9-9.2 (H, Ar.); 9.4-9.7 (V-NH-N); 1 1 .2- 1 1 .4 (OH, Ar). ¹³C{¹ H} (100.62 MHz, DMSO, 298 K): d = 14.30-16.5 (CH₃-CN) 32.6-35.4 (CH, furf.); 103.9-105.3 (CH, Ar); 1 16.3-1 18.3 .1 (m-phenol); 1 19.1 -121 .2 (p-phenol); 122.2-123-4 (C furf.)- 124.2-125.2 (C, furf.) 131 .2-132.5 ( o-phenol); 132.9-134.6 (C, furf.); 140.3 (C-NO₂); 158.1 -158.5 (;- phenol); 160.3-161 .4 (HO-C, Ar).

Method b) A suspension consisting of 5 g (0.014 mol) of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}- benzene-1 ,3-diol, 1 .93 g (0.015 mol) of p-nitrophenol (Aldrich), 40 ml_ of formaldehyde (Aldrich) (1.42 mol) and 6.8 ml_ of NaOH (40 wt%) is heated to reflux at 1 10 °C for 10 h. The resulting red precipitate is washed with cold water (3 x100 ml) and then with hot water (50 °C) to remove low molecular weight oligomers. Yield 6 g. Example 3

PREPARATION OF POLYMER P3

Method a). To a suspension of 5 g (0.014 mol) of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}- benzene-1 ,3-diol in 60 ml_ of H₂O are added 1 .94 g (0.014 mol) of 4-hydroxybenzoic acid (Aldrich), 0.85 g (0.028 mol) of p-formaldehyde (Aldrich) and 30 ml_ of KOH (7 %). The resulting suspension is kept at reflux for 6 h (1 10°C). The red solid that forms is collected by filtration and washed thoroughly with water (4 x100 ml_) and water/acetone (1 :1 v:v) to remove low molecular weight fractions. The solid product is then dried under reduced pressure and at 60 °C to constant weight. Yield 5.5 g. Elemental analysis: C, 60.40; H, 4.3; N, 13.4 % (The analysis is in agreement with the polymer composition with x = 1 and n = 1 ). CaIc: C, 59.74; H, 3.93; N.12.12 %.

FT-IR, (?/cm-1 ) : 3600-3120 (? OH); 3240 (? NH); 3100 (? CH aromatic); 1640 (? CN); 1610 (?as.CO2); 1585 (? NH); 1510 (?s.NO2); 1510 (?as.NO2); 1400 (?as CO2); (1330 (d OH); 830 (? C-NO₂ Ar.). UV-Vis: ?max = 380 nm; shoulder a 463 nm (DMSO, 294 K). ¹H NMR (400.13 MHz, 298 K): (CD₃COCD₃): δ = 2.4-2.8 (NC-CH₃ -); 3.8-4.4 (Ar-CH₂-Ar); 6.4-6.8 (C-H, aromatic); 6.8-7.4 (C-H, phenol); 7.6-7.9 (C-H, aromatic); 8.3-8.6 (H, phen); 8.9-9.2 (H, aromatic), 9.5-9.8 (Ar-NH-N), 1 1 .2-1 1 .6 (Ar-OH), 12.0-13.5 (Ar-OH) ppm. ¹³C NMR: (100.62 MHz, CD₃COCD₃, 298 K): δ = 30-32(Ar-CH₂-Ar); 102-120 (C, Ar); 137 (O₂N-C, Ar); 143 (HN-C, Ar); 159 (Ar-C=N-); 160-161 (HO-C Ar) ppm.

Method b). A suspension consisting of 5 g (0.014 mol) of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]- ethyl}-benzene-1 ,3-diol, 1 .93 g (0.015 mol) of 4-hydroxybenzoic acid (Aldrich), 40 ml_ of formaldehyde (Aldrich) (1.42 mol) and 6.8 ml_ of NaOH (40 wt%) is heated to reflux at 1 10 °C for 10 h. The resulting red precipitate is washed with cold water (3 x100 ml) and then hot water (50 °C) to remove low molecular weight oligomers and dried to constant weight at 60 °C Yield 6 g. Example 4

PREPARATION OF AN ANODIC CATALYST CONTAINING IRON, COBALT and NICKEL. To a suspension of 5 g of polymer P1 in 300 mL of water, are added 1 .13 g of cobalt acetate tetrahydrate (Aldrich), 1.13 g of nickel acetate tetrahydrate (Aldrich) and 0.83 g of anhydrous iron acetate (Aldrich) The pH of the mixture is adjusted to 9 using 70 mL of NaOH 1 M and is then stirred vigorously for 12 h. A dark red precipitate forms which is collected by filtration, washed thoroughly with water and then dried under vacume at 70 °C to constant weight. Yield = 5.1 1 g. Metal content (wt%) Co = 3.98 %, Ni = 3.27 % and Fe = 2.95 % (ICP-AES analysis). To a suspension of 1 g of this compound (obtained by sonication) in 500 mL of acetone is added 5 g of Vulcan XC-72R (Cabot). The resulting mixture is vigorously stirred at room temperature for 4 h and then cooled to 0 °C. A solution of 2 g NaBH4 dissolved in 100 mL of water is slowly added and the temperature allowed to warm to room temperature. After 2 h the resulting solid is filtered, washed with water (3 x 100 mL) and then dried under reduced pressure at 70 °C to constant weight. Metal content (wt%) Co = 0.66 %, Ni = 0.63 % and Fe = 0.61 % (ICP-AES analysis). The product is conserved under an inert atmosphere (N₂ or Ar).

Alternatively, the reduction can be achieved using a current of hydrogen gas. In this case 5 g of the following mixture; POLYMER-PI-Fe, Co, Ni and Vulcan (1 :5 wt/wt), is introduced into a quartz furnace heated at 360 °C under a flow of hydrogen gas for 2 h. The product is conserved under an inert atmosphere (N₂ or Ar). Metal content (wt%) Co = 0.66 %, Ni = 0.63 % and Fe = 0.61 % (ICP- AES analysis). Atomic ratio = Co₃₃Ni₃₃Fe₃₄

Other anodic catalysts containing Fe, Co and Ni can be formed using POLYMERS P2 and P3

(described in examples 2 and 3) instead of POLYMER P1.

Example 5

PREPARATION OF AN ANODE CATALYST CONTAINING PLATINUM To a suspension of 1 g of POLYMER P1 in 100 ml_ of water is added 0.2 g of hexachloroplatinic acid (H₂PtCI₆). The pH of this mixture is adjusted to 9 using 50 ml_ of NaOH 1 M and vigorously stirred at room temperature for 6 h. The red precipitate that forms is filtrated, washed with water and then dried under reduced pressure at 70 °C to constant weight. Yield = 0.8 g. Pt content = 6 wt% (ICP-AES).

To a sonicated suspension of 0.5 g of the above compound in 100 ml_ of acetone is added 5 g of Vulcan XC-72R (Cabot) and then vigorously stirred at room temperature for 4 h. The resulting mixture is then cooled to 0 °C and 0.7 g of NaBH₄ is added in small portions. The mixture is allowed to warm to room temperature and after 2 h the resulting solid is filtered, washed with water (3 x 50 ml_) and dried under reduced pressure at 70 to constant weight. The percentage of Pt in weight is 0.55 % (ICP-AES analysis).

Alternatively, the reduction can be performed with a current of hydrogen gas. In this case 5 g of the mixture of POLYMER PI -Pt and Vulcan (1 :10 wt/wt), is reduced in a quartz furnace under a flow of hydrogen at 360 °C for 2 hours. The percentage of Pt in weight is 0.55 % (ICP-AES analysis). To obtain anodic catalysts containing Pt, even POLYMERS P2 and P3 can be used as described in examples 2 and 3. Example 6

PREPARATION OF A PLATINUM AND RUTHENIUM BASED ANODIC CATALYST To a suspension containing 1 g of POLYMER P1 in 100 mL of water is added 0.2 g of hexachloroplatinic acid (H₂PtCI_6, Aldrich) dissolved in water and 0.31 g of ruthenium trichloride hexahydrate (RuCI₃ 6H₂O, Aldrich) dissolved in water. The mixture is adjusted to pH 9 using 50 mL of 1 M NaOH and vigorously stirred at room temperature for 6 h. The maroon precipitate that forms is filtered, washed thoroughly with water and dried under vacuum at 70 °C to constant weight. Yield 0.9 g. The percentage of Pt in weight is 6 %, Ru 7% (ICP-AES analysis). To a suspension of 0.5 g of the previous compound in 100 mL of acetone (finely dispersed using an ultrasound probe for 30 min) is added 5 g of Vulcan XC-72R (Cabot). The suspension id vigorously stirred at room temperature for 4 h. The resulting mixture is then cooled to 0 °C and 0.7 g of NaBH₄ is added in small portions. The mixture is allowed to warm to room temperature and after 2 h the resulting solid is filtered, washed with water (3 x 50 mL) and dried under vacuum at 70 to constant weight. The percentage of Pt in weight is 0.55 % and Ru 0.66 % (ICP-AES analysis).

Alternatively, the reduction can be performed with a current of 1 bar hydrogen gas. In this case 5 g of the mixture of POLYMER PI -Pt-Ru and Vulcan (1 :10 wt/wt), is reduced in a quartz furnace under a flow of hydrogen at 360 °C for 2 hours. The percentage of Pt in weight is 0.55 % and Ru 0.66 % (ICP-AES analysis). Atomic ratio = Pt₄₅Ru₅₅ To obtain anodic catalysts containing Pt and Ru, even POLYMERS P2 and P3 can be used as described in examples 2 and 3. Example 7

PREPARATION OF COBALT BASED CATHODIC CATALYST To a suspension containing 7 g of POLYMER P1 in 200 mL of water are added 3.6 g of cobalt(ll) acetate tetrahydrate (Aldrich). The mixture is adjusted to pH 9 by the addition of 100 mL of 1 M NaOH and is vigorously stirred at room temperature for 15 h. The red/brown precipitate that forms is collected by filtration, washed with water (3 x 40 ml_) and dried under reduced pressure at 70 °C to constant weight. Yield 7.5 g. The percentage of Co in weight is 3.64 % (ICP-AES analysis). To a suspension of 3.6 g of the previous compound in 600 ml_ of acetone (finely dispersed using an ultrasound probe for 30 min) is added 36 g of Vulcan XC-72R (Cabot). The suspension is vigorously stirred at room temperature for 3 h and the solvent removed. The resulting solid is introduced into a quartz reactor and heated to 600 under a flow of nitrogen gas for 2 h. The percentage of Co in weight is 0.35 % (ICP-AES analysis).

To obtain cathodic catalysts containing Co, even POLYMERS P2 P3, P4 and P5 can be used as described in examples 2, 3, 4 and 5.

Example 8

PREPARATION OF NICKEL BASED CATHODIC CATALYST

To a suspension containing 7 g of POLYMER P1 in 200 mL of water are added 3.6 g of nickel(ll) acetate tetrahydrate (Aldrich). The mixture is adjusted to pH 9 by the addition of 100 mL of 1 M

NaOH and is vigorously stirred at room temperature for 15 h. The red/brown precipitate that forms is collected by filtration, washed with water (3 x 40 mL) and dried under reduced pressure at 70 °C to constant weight. Yield 7.5 g. The percentage of Ni in weight is 3.2 % (ICP-AES analysis).

To a suspension of 3.6 g of the previous compound in 600 mL of acetone (finely dispersed using an ultrasound probe for 30 min) is added 36 g of Vulcan XC-72R (Cabot). The suspension is vigorously stirred at room temperature for 3 h and the solvent removed. The resulting solid is introduced into a quartz reactor and heated to 600 under a flow of nitrogen gas for 2 h. The percentage of Ni in weight is 0.31 % (ICP-AES analysis).

To obtain cathodic catalysts containing Ni, even POLYMERS P2 and P3 can be used as described in examples 2 and 3.

Example 9

PREPARATION OF PLATINUM BASED CATHODE CATALYST

To a suspension containing 2 g of POLYMER P1 in 200 mL of water are added 0.4 g of hexachloroplatinic acid (H₂PtCI_6, Aldrich). The mixture is adjusted to pH 9 by the addition of 100 mL of 1 M NaOH and is vigorously stirred at room temperature for 10 h. The dark red precipitate that forms is collected by filtration, washed with water (3 x 40 mL) and dried under reduced pressure at

70 °C to constant weight. Yield 1.8 g. The percentage of Pt in weight is 6 % (ICP-AES analysis).

To a suspension of 0.5 g of the previous compound in 100 mL of acetone (finely dispersed using an ultrasound probe for 30 min) is added 5 g of Vulcan XC-72R (Cabot). The suspension is vigorously stirred at room temperature for 3 h and the solvent removed. The resulting solid is introduced into a quartz reactor and heated to 600 under a flow of nitrogen gas for 2 h. The percentage of Pt in weight is 0.55 % (ICP-AES analysis).

To obtain cathodic catalysts containing Pt, even POLYMERS P2 and P3 can be used as described in examples 2 and 3. Example 10

PREPARATION OF AN ANODE FOR A FUEL CELL

10 g of the compound obtained by the methods described above in examples 4,5 and 6 are suspended in 100 mL of a mixture of water/ethanol 1 :1 (v/v). To this vigorously stirred suspension is added 3.2 g of PTFE (polytetrafluoroethylene) in water (60 wt%). After 10 min a flocculous solid (FS) forms that is separated by decantation. Instead of Vulcan other activated carbon supports can used such as RDBA, R-5000, NSN-III or graphite Keiten black and Raven amongst others. Method (a): 200 mg of compound FS is uniformly pasted onto a carbon paper disc (Teflon^®-treated carbon paper, Fuel Cell Scientific) and then pressed at 80 Kg/cm². The electrode thus formed is sintered in a furnace at 350 °C under a flow of inert gas for a few minutes (N₂ or Ar).

Method (b): 200 mg of compound FS is uniformly pasted onto a steel netting disc that is then pressed at 100 Kg/cm². The electrode thus formed is sintered in a furnace at 350 °C under a flow of inert gas for a few minutes (N₂ or Ar). Method (c): 0.5 mL of a suspension in acetone (50 mL) of POLYMER described in examples 1 ,2,3,4 and 5, containing the metal compounds described in examples 6,7 and 8 are deposited on various forms of conductive support material, for example silver powder or nickel pressed and sintered. The supports are then immersed in an aqueous solution (100 mL) of 1 g of NaBH₄ for 10 min. at room temperature. The reduction of the metal can be obtained by introducing the support that has absorbed the METALISED POLYMER in a quartz reactor and is heated in under a flow of hydrogen gas at 365 for 2 h. Other conductive substrates can be powdered ceramic materials like Wc, MOc amongst others. Example 11 PREPARATION OF A CATHODE FOR A FUEL CELL

10 g of the compound obtained by the methods described above in examples 7,8 and 9 are suspended in 100 mL of a mixture of water/ethanol 1 :1 (v/v). To this vigorously stirred suspension is added 3.2 g of PTFE (polytetrafluoroethylene) in water (60 wt%). After 10 min. a flocculous solid (FS) forms that is separated by decantation. Instead of Vulcan other activated carbon supports can used such as RDBA, R-5000, NSN-III or graphite Keiten black and Raven amongst others.

Method (a): 200 mg of compound FS is uniformly pasted onto a steel netting disc that is then pressed at 100 Kg/cm². The electrode thus formed is sintered in a furnace at 350 °C under a flow of inert gas for a few minutes (N₂ or Ar). Method (b): 0.5 mL of a suspension in acetone (50 mL) of 200 mg of POLYMER described in examples 4, 5 and 6 containing the metal compounds described in examples 6,7 and 8 are deposited on various forms of conductive support material, for example silver powder or nickel pressed and sintered. The supports are heated at 500 °C under a flow of inert gas for a few minutes. Other conductive substrates can be powdered ceramic materials like Wc, MOc amongst others. Method (c): In this method are used support materials impermeable to water as know in the state of the art. 0.5 ml_ of a suspension in acetone (50 ml_) of 200 mg of POLYMER containing the metals described in examples 9, 10 and 11 are suspended in water (50 ml_) together with a powdered porous conductive material (3 g) and in the presence of 2 g of PTFE or high density polyethylene. The solvent is removed by evaporation under reduced pressure and then the resulting solid is pressed at 100 Kg to give sheets or discs of various dimensions that are heated at 150 °C under flow of inert gas (N₂ or Ar) for a few minutes.

Claims

1. Copolymer resins of formula (A) obtained by the condensation of 4-{1 -[(2,4-dinitrophenyl)- hydrazone]-ethyl}-benzene-1 ,3-diol} with phenol and furfural in the presence of an acid or basic catalyst in water/ethanol mixtures and at temperatures between 20 and 150 °C and having a molecular weight between 1000 and 50000. In this compound x can vary between 1 and 2, n can vary between 1 and 3 and y can vary between 2 and 120.

2. Anodic or cathodic catalysts for fuel cells obtained by the treatment (reduction or inert atmosphere pyrolysis) of metal complexes formed from a salt or transition metal compound, alone or in combination with other salts or metal compounds and the copolymeric resin (A) of claim 1 .

3. Anodic or cathodic catalysts for fuel cells obtained by the treatment (reduction or inert atmosphere pyrolysis) of metal complexes formed from a salt or a transition metal compound, alone or in combination with other salts or metal compounds and the copolymer resins obtained by the condensation of hydroxy or aminoacetophenone with formaldehyde or furfural and hydroxyaromatic compounds or substituted aromatic acids (chloro, amino, nitro) and also with olm alkyl benzoic acids, o/m/p-chloroaniline, o/m/p-toluidine, chloroacetophenone, naphthol, bis- phenols, phenolphthalein and hydroxyquinoline, in the presence of an acid or basic catalyst in alcohol/water mixtures and at temperatures between 20 and 150 °C and having a molecular weight between 1000 and 50000.

4. Anode or cathode catalysts for fuel cells obtained by the treatment (reduction or inert atmosphere pyrolysis) of metal complexes formed from a salt or transition metal compound, alone or in combination with other salts or metal compounds and the copolymer resins obtained by the condensation of 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}-benzene-1 ,3-diol} with a series of hydroxy or substituted aromatic acids (chloro, amino, nitro) and also with olm alkyl benzoic acids, o/m/p-chloroaniline, o/m/p-toluidine, chloroacetophenone, naphthol, bis-phenols, phenolphthalein and hydroxyquinoline and formaldehyde or furan and in alcohol/water mixtures and at temperatures between 20 and 150 °C and having a molecular weight between 1000 and 50000.

5. Catalysts according to claim 3 in which the hydroxyacetophenone is a compound of formula (B) and the aromatic compound has formula (C).

R-_I, in compound of formula (B) represents O, N, N-NH₂, NHCONH₂ and R₂ and R₃ represent independently groups like H and OH. R, R₅, R₃, R₇, R₃ and R₃ in compound of formula (C) independently represent un group comprised of H, OH, ether, amine, acid, nitro, halogen, aryl and linear or branched alkyl groups having 1 to 15 carbon atoms possibly functionalised with OH or ketone or joined in a way as to form condensed or non condensed rings with the aromatic ring of group of formula (C) with the proviso that at least 2 C-H groups must be present in the aromatic ring of compound of formula (C).

6. Catalysts according to claim 4 in which 4-{1 -[(2,4-dinitrophenyl)-hydrazone]-ethyl}- benzene-1 ,3-diol} is a compound of formula (D) and the substituted aromatic compound has formula (C).

In which Ri₀ is chosen from a group consisting of: H and a radical hydrocarbon having from 1 to 10 carbon atoms possibly halogenated;

Rn and Ri₂ independently represent a electron acceptor chosen from the group consisting of hydrogen, halogen, acyl, ester, carboxylic acid, formyl, nitrile, sulfonic acid, aryl and linear or branched alkyl groups gruppi having 1 to 15 carbon atoms possibly functionalised with halogens or joined together in a way as to form one or more condensed rings with the phenyl ring and nitro groups.

7. Catalysts according to the claims 3 and 5 in which the said copolymeric resins are polymers represented by formulas (E) and (F).

in which y can vary from 2 to 120, x can vary between 1 and 2, n can vary from 1 to 3 and R|, R₂, R3, R4 ,Rδ Re, R₇, Rβe R9 are defined as above.

8. Catalysts according to claims 4 and 6 in which the said copolymeric resins are represented by the formula (G) and (H)

(G)

in which y can vary from 2 to 120, x can vary between 1 and 2, n can vary from 1 to 3 and R₄, R₅, R₆, R₇ ,R_8j R₉, Rio, Rn and Ri₂ are defined as above.

9. Catalysts according to the claims 3, 4, 5 and 6 in which the compounds of formula (B) and (C) or (D) and (C) incorporated in the polymeric resins are bridged by a group of the formula CHR₁, where R1 can be any aromatic ring or heteroatom or a linear or branched alkyl group having 1 to 15 carbon atoms possibly functionalised with alcohol, aldehyde, amine, nitro acid and halogen groups.

10. Catalysts according to the claims 2-9 in which the metals alone or in combined are chosen from the group comprised from Fe, Co, Ni, Cu, Pt, Pd, Ru, Rh, Ir, Mo, Sn, La, V, Mn.

11. Catalysts according to the claims 2-10 in which the said salts are chosen from the group comprised of: carboxylates, halogens, alcoholates, acetylacetonates, formates, oxalates, malonates and analogous organic salts and their mixtures or carbonates and bicarbonates and their mixtures.

12. A process for the preparation of a catalyst according to the claim 2-1 1 in which:

- a mixture of salts or compound of iron, cobalt and nickel are first complexed with the polymer;

- the resulting complex polymer/FeCoNi is supported on a conductive porous carbon material; -the resulting product is:

-treated in the solid state with hydrogen gas at a temperature between 50 and 900 ⁰C. -treated in solution/suspension with chemical reducing agents according to the state of the art.

13. Process for the preparation of a catalyst according to the claims 2-11 in which:

- a salt or compound of cobalt is first complexed by the polymer;

- the resulting complex polymer/Co is supported on a conductive porous carbon material;

- the resulting product is then heated in an inert atmosphere to 1000 °C.

14. Process for the preparation of a catalyst according to the claims 2-11 in which:

- a salt or compound of platinum is first complexed by the polymer;

- the resulting complex polymer/Pt is supported on a conductive porous carbon material;

- the resulting product is either:

- treated in the solid state with hydrogen gas at a temperature between 50 and 900 °C. -treated in solution/suspension with chemical reducing agents according to the state of the art. - heated in an inert atmosphere to 1000 °C

15. Process for the preparation of a catalyst according to the claims 2-11 in which:

- a salt or compound of nickel is first complexed by the polymer;

- the resulting complex polymer/Ni is supported on a conductive porous carbon material; - the resulting product is then heated in an inert atmosphere to 1000 °C.

16. Process for the preparation of a catalyst according to the claims 2-11 in which:

-a mixture of a salt or compound of platinum and one or more salts or metal compounds are complexed by the polymer;

- the resulting complexed polymer known as the METALISED POLYMER, is supported on porous conductive carbon material of the state of the art. The resulting product is:

- treated in the solid state with hydrogen gas at a temperature between 50 and 900 °C. -treated in solution/suspension with chemical reducing agents according to the state of the art.

- heated in an inert atmosphere to 1000 °C

17. Process for the preparation of a catalyst according to the claims 2-1 1 in which: - a salt or compound of platinum is first complexed by the POLYMER

- the resulting complex Pt/polymer is then treated with one or more other metal salts;

- the resulting product POLYMER-Pt METALISED is supported on a porous conductive carbon material of the state of the art and the resulting product is then:

- heated in an inert atmosphere to 1000 °C

18. Process for the preparation of a catalyst according to the claims 2-11 in which the polymer/Pt alone or with platinum and one or more metals are supported on porous metal oxides of the state of the art and the resulting product is then: - treated in the solid state with hydrogen gas at a temperature between 50 and 900 °C.

-treated in solution/suspension with chemical reducing agents according to the state of the art.

- heated in an inert atmosphere to 1000 °C

19. Catalysts according to the claims 2-11 based on platinum prepared according to the processes in claims 16, 17 and 18 in which the quantity of platinum varies from 0.1 and 50 wt% with respect to the support material.

20. Catalysts according to the claims 2-1 1 based on iron, cobalt and nickel prepared according to the process in claim 12 in which the quantity of metal varies from 0.1 and 50 wt% with respect to the support material and the atomic ratio between the various metals varies with all possible combinations.

21 . Catalysts according to the claims 2-1 1 based on platinum and ruthenium prepared according to the processes in claims 17, 18 and 19 in which the quantity of metal varies from 0.1 and 50 wt% with respect to the support material and the ratio between platinum and ruthenium varies from 99:1 a 1 :99.

22. Catalysts according to the claims 2-11 based on platinum and any other transition or non transition metal prepared according to the processes in claims 16, 17 and 18 in which the quantity of metal varies from 0.1 and 50 wt% with respect to the support material and the ratio between platinum and the other metal varies from 99:1 a 1 :99.

23. Catalysts according to the claims 2-1 1 based on platinum combined with two or more metals prepared according to the claims 16, 17 and 18 in which the quantity of metal varies from 0.1 and 50 wt% with respect to the support material and the ratio between the various metals has all the possible combinations.

24. Electrodes for fuel cells comprising a catalyst according to the claims 4-12 and 20-23.

25. Anode electrodes consisting of a conductive support of carbon paper and a catalyst according to the claims 4-1 1.

26. Anode electrodes consisting of a conductive support of carbon paper and a catalyst according to the claim 20 in which Fe, Co and Ni are preferably of stoichiometric ratio.

27. Cathode electrodes consisting of a catalyst according to the claims 4-1 1 supported on a finely dispersed nickel or on carbon paper.

28. Cathode electrodes consisting of a cobalt based catalyst according to claim 13 supported on a conductive material chosen among carbon paper or a finely dispersed metal.

29. Electrochemical fuel cells for the production of electric energy comprising electrode catalysts of the type according to the claims 24 to 28, a proton exchange membrane and an electrolyte.

30. Electrochemical fuel cells for the production of electric energy comprising an electrode catalyst of the type according to the claims 24 to 28, an anionic exchange membrane and an electrolyte.

31 . Electrochemical fuel cells for the production of electric energy comprising electrode catalyst according to the claims 24 to 28, an anion or proton exchange membrane and a liquid electrolyte.

32. Electrochemical cells for the production of electric energy comprising an anode consisting of an electrode according to claims 25 and 26, a known cathode, a anion or proton exchange membrane and a liquid electrolyte.

33. Electrochemical cells for the production of electric energy comprising an cathode consisting of an electrode according to claims 27 and 28, a known anode, a anion or proton exchange membrane and a liquid electrolyte.

34. Electrochemical cells defined in the claims 31 and 32 comprising a proton exchange membrane.

35. Electrochemical cells defined in the claims 31 and 32 comprising an anion exchange membrane.

36. Electrochemical cells defined in the claims 31 and 33 comprising a liquid alkaline electrolyte.

37. Electrochemical cells defined in the claims 31 and 33 comprising a liquid acid electrolyte.

38. Electrochemical cells according to the claims from 29 to 37 in which the fuel is hydrogen gas, reformed hydrogen; alcohols, methanol, ethanol and ethylene glycol; hydrazine and hydroxylamine; borohydrides with various metal cations and non metal cations; aldehydes, acids, hydrocarbons like methane (natural gas), ethane, propane and butane; fossil fuels like gasoline and kerosene.