Abstract: An electrode catalyst for a fuel cell consists principally of a carbon support, and a platinum catalyst or a platinum-alloy catalyst supported on the carbon support. In the electrode catalyst, at least 0.7 mmol of an acid per gram of the electrode catalyst is present on the carbon support.

Abstract: This invention provides a catalyst material comprising a conductive material coated with a polynuclear complex molecule derived from at least two types of heteromonocyclic compounds and a catalyst metal coordinated to the coating layer of the polynuclear complex molecule, and a catalyst material comprising a conductive material coated with a polynuclear complex molecule derived from a heteromonocyclic compound and a catalyst metal, which is a composite of a noble metal and a transition metal, coordinated to the coating layer of the polynuclear complex molecule. Such catalyst material of the invention has excellent catalytic performance and serviceability as, for example, an electrode of fuel cells.

Abstract: An object of the present invention is to optimize an anode catalyst layer such that high output performance can be achieved even under low-humidity conditions. In addition, another object of the present invention is to provide a polymer electrolyte fuel cell having such an anode catalyst layer. The following is obtained: an anode catalyst layer for a polymer electrolyte fuel cell, which comprises a carbon support on which a catalyst is carried and a hydrogen ion-conductive polyelectrolyte, and wherein the catalyst is carried by a carbon support for which the hydrophilic characteristic value specified based on a value representing the amount of adsorbed water vapor/the amount of adsorbed nitrogen is 0.02 or less, or the hydrophilic characteristic value for the catalyst-carrying carbon support is 0.30 or less.

Abstract: An electrode catalyst for a fuel cell, which has improved performance compared with conventional platinum alloy catalysts, a method for producing the electrode catalyst, and a polymer electrolyte fuel cell using the electrode catalyst are provided. The electrode catalyst for a fuel cell comprises a noble-metal-non-precious metal alloy that has a core-shell structure supported on a conductive carrier. The composition of the catalyst components of the shell is such that the amount of the noble metal is greater than or equal to the amount of the non-precious metal.

Abstract: The present invention specifies the physical property valves of a catalytic layer correlating with the performance of a fuel cell, and provides the catalytic layer having the physical proper values and a fuel cell. Specifically, in a fuel cell having a membrane-electrode assembly provided with a catalytic layer 13 on each side of an electrolyte membrane 10, an electrode powder constituting the catalytic layer 13 shall have an amount of adsorbed water vapor in a range of 52 to 70 cm3(STP)/g by a value measured when the water-vapor partial pressure is 0.6, which is determined from the adsorption isotherm of water. The fuel cell having the catalytic layer with the use of the electrode powder having the amount of adsorbed water vapor in this range has the output performance of 0.6 A/cm2 or higher by current density at 0.6 V, in a less humidified condition and a more humidified condition.

Abstract: This invention provides a macrocyclic-organic-compound-based catalyst for reducing oxygen having high oxygen-reducing activity. This oxygen-reducing catalyst comprises a conductive support and, supported thereon, a porphyrin complex represented by formula (I): wherein Rs each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, an amino group, a hydroxyl group, a nitro group, a phenyl group, or a cyano group or adjacent Rs together form a methylene chain having 2 to 6 carbon atoms or aromatic ring; R's each independently represent a thienyl group; and M represents a metal atom selected from the group consisting of Cu, Zn, Fe, Co, Ni, Ru, Pb, Rh, Pd, Pt, Mn, Sn, Au, Mg, Cd, Al, In, Ge, Cr, and Ti, provided that M may bind to a halogen atom, an oxygen atom, —OH, a nitrogen atom, NO, or ?CO.

Abstract: This invention provides a catalyst material comprising a conductive material coated with a polynuclear complex molecule derived from at least two types of heteromonocyclic compounds and a catalyst metal coordinated to the coating layer of the polynuclear complex molecule, and a catalyst material comprising a conductive material coated with a polynuclear complex molecule derived from a heteromonocyclic compound and a catalyst metal, which is a composite of a noble metal and a transition metal, coordinated to the coating layer of the polynuclear complex molecule. Such catalyst material of the invention has excellent catalytic performance and serviceability as, for example, an electrode of fuel cells.

Abstract: It is an object of the present invention to provide a cathode catalyst for fuel cells containing platinum and iron which can maintain the durability of a battery and can make a battery high output. The cathode catalyst for fuel cells comprises a supporting layer which consists of an alloy containing platinum and iron and further containing the third component which has an affinity for iron including one or more sorts of elements selected from the group consisting of tungsten, titanium, molybdenum, rhenium, zinc, manganese, tin, tantalum and rhodium, and a support on which the supporting layer is loaded. A catalyst using an alloy containing platinum and iron enables the batteries to become high output. By alloying one or more sorts of elements of the third component which has an affinity for iron with an alloy containing platinum and iron, it is possible to prevent eluting of the iron into the electrolyte.

Abstract: The invention relates to methods of preparing metal particles on a support material, including platinum-containing nanoparticles on a carbon support. Such materials can be used as electrocatalysts, for example as improved electrocatalysts in polymer electrolyte membrane fuel cells (PEM-FCs).

Abstract: It is an object of the present invention to provide a cathode catalyst for fuel cells containing platinum and iron which can maintain the durability of a battery and can make a battery high output. The cathode catalyst for fuel cells comprises a supporting layer which consists of an alloy containing platinum and iron and further containing the third component which has an affinity for iron including one or more sorts of elements selected from the group consisting of tungsten, titanium, molybdenum, rhenium, zinc, manganese, tin, tantalum and rhodium, and a support on which the supporting layer is loaded. A catalyst using an alloy containing platinum and iron enables the batteries to become high output. By alloying one or more sorts of elements of the third component which has an affinity for iron with an alloy containing platinum and iron, it is possible to prevent eluting of the iron into the electrolyte.

Abstract: An electrode catalyst for a fuel cell includes a conductive support, and catalytic particles loaded on the conductive support. The catalytic particles include platinum and a base metal being on the lower end of the electrochemical series with respect to platinum. The number of the atoms of the base metal, forming metallic oxides without alloying with the platinum, is less than 5 atomic % of the number of the atoms of the platinum on a surface of the catalytic particles. The electrode catalyst is produced by loading the platinum and base metal on the conductive support, alloying the platinum and base metal thereon by a heat treatment, thereby making the catalytic particles, and removing metallic oxides from a surface of the catalytic particles. The electrode catalyst is less expensive comparatively, exhibits high catalytic activities, and hardly lowers the battery performance of fuel cells.

Abstract: In a powder-form electrode catalyzer for a fuel cell which comprises catalyst particles that contain platinum, and an electrically conductive support supporting the catalyst particles, the ratio between a mean value D111 of crystallite diameters of catalyst particles in a direction perpendicular to a (111) crystal face and a mean value D100 of crystallite diameters of the catalyst particles in a direction perpendicular to a (100) crystal face is D100/D111<1, and a mean crystallite diameter of the catalyst particles is at most 5 nm. Due to a large surface area that functions as a catalyst and a great proportion of the catalyst particles that have (100) crystal faces present on surfaces, the electrode catalyzer has high oxygen reduction activity.

Abstract: An electrode catalyst for a fuel cell includes a conductive support, and catalytic particles loaded on the conductive support. The catalytic particles include platinum and a base metal being on the lower end of the electrochemical series with respect to platinum. The number of the atoms of the base metal, forming metallic oxides without alloying with the platinum, is less than 5 atomic % of the number of the atoms of the platinum on a surface of the catalytic particles. The electrode catalyst is produced by loading the platinum and base metal on the conductive support, alloying the platinum and base metal thereon by a heat treatment, thereby making the catalytic particles, and removing metallic oxides from a surface of the catalytic particles. The electrode catalyst is less expensive comparatively, exhibits high catalytic activities, and hardly lowers the battery performance of fuel cells.

Abstract: A catalyst for purifying exhaust gases comprises a catalyst carrier made of potassium titanate and a noble metal loaded on the catalyst carrier. The catalyst carrier is substantially free from alumina. This catalyst can oxidize at least hydrocarbons in exhaust gases at a high catalytic activity even at low temperatures, and at the same time can suppress SO.sub.2 from converting into sulfates. This catalyst does not employ substance like alumina exhibiting solid acidity as a catalyst carrier. Further, this catalyst can be used for purifying exhaust gases from diesel engines to suppress particulates and sulfates from being emitted, and to improve conversions of hydrocarbons and carbon monoxide.

Abstract: An electrically heating catalytic apparatus that quickly heats catalyst to an activation temperature even when the engine is started at a low temperature below the catalyst activation temperature. The apparatus employs an electrically conductive catalyst carrier that is electrically heated. The carrier is provided with local hot spots to be energized. Since the heat is locally generated, the heat capacity of the catalyst carrier is small to shorten a temperature increasing time.

Abstract: An electrically heating catalytic apparatus that quickly heats catalyst to an activation temperature even when the engine is started at a low temperature below the catalyst activation temperature. The apparatus employs an electrically conductive catalyst carrier that is electrically heated. The carrier is provided with local hot spots to be energized. Since the heat is locally generated, the heat capacity of the catalyst carrier is small to shorten a temperature increasing time.

Abstract: An electrically heated catalytic converter having a scroll-like cylindrical laminated assembly in which belts of thin corrugated metal sheet and a thin plain metal sheet are laminated and wound around a center electrode, and the outermost layers are connected to an outer electrode. The corrugated metal sheet has an insulating coating made of a metal oxide, and the plain metal sheet has no insulating coatings. Conductive connections in which the corrugated metal sheet and the plain metal sheet are electrically connected to each other through the insulating coating of the corrugated metal sheet are made at predetermined positions in the layers of the laminated assembly and electric paths of desired shapes are formed by these conductive connections. The corrugated metal sheet and the plain metal sheet are connected in the areas around the respective conductive connections in such a manner that the metal sheets are isolated from each other.

Abstract: An exhaust gas purifying catalyst is characterized in that at least one kind of catalyst metal is loaded on a layered porous silica or a layered porous silica-metal oxide. The exhaust gas purifying catalyst is used as an oxidation catalyst for purifying hydrocarbon and carbon monoxide, or a reduction catalyst for purifying nitrogen oxides (NO.sub.x), which is suitable for purifying exhaust gases in automobiles. An exhaust gas purifying apparatus includes the above exhaust gas purifying catalyst and an absorbent for trapping hydrocarbon components, in which aromatic HC such as trimethylbenzene and the like are effectively trapped.

Abstract: An engine comprising an exhaust passage having therein a NO.sub.x absorbent which absorbs the NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent is lean and releases the absorbed NO.sub.x when the concentration of oxygen in the exhaust gas is lowered. When the air-fuel ratio of air-fuel mixture fed into the engine cylinder is made a rich air-fuel ratio or the stoichiometric air-fuel ratio, a secondary air is fed into the exhaust passage upstream of the NO.sub.x absorbent to make the air-fuel ratio of exhaust gas lean.

Abstract: A sprayed member which has a ceramic-sprayed layer formed on the surface of a parent material of an aluminum alloy through a sprayed bond layer. A diffusion layer occupies 20 to 50% of the entire interface between the bond layer and the parent material. The interface between the diffusion layer and the parent material and the interface between the bond layer and the parent material are finely roughened to have a height of several microns. The diffusion layer and the fine roughness are formed by preheating the surface of the parent material at a temperature ranging from 260.degree. to 500.degree. C. prior to spraying the parent material with a material for the bond layer so that they can together enhance the adherency between the bond layer and the parent material.