A method for preparing particles comprising a material suitable for catalysing oxygen reduction or hydrogen oxidation, the particles being grafted with grafts consisting of at least one specific polymer comprising at least one repeating fluorinated styrene unit bearing at least one proton-conducting group.

The present invention relates to a catalyst for solid polymer fuel cells in which catalyst particles containing Pt as an essential catalyst metal are supported on a carbon powder carrier. The catalyst has good initial activity and good durability. When the catalyst is analyzed by X-ray photoelectron spectroscopy after potential holding at 1.2 V (vs. RHE) for 10 minutes in a perchloric acid solution, a ratio of zero-valent Pt to total Pt is 75% or more and 95% or less. The present inventive catalyst metal is preferably one obtained by alloying Pt with one of Co, Ni and Fe, and further with one of Mn, Ti, Zr and Sn. In addition, it is preferable that a fluorine compound having a CF bond is supported on at least the surfaces of catalyst particles in an amount of 3 to 20 mass % based on the total mass of the catalyst.

The invention relates to systems and methods for successful operation of acid mediated proton exchange membrane fuel cell (PEMFC), and highly efficient, earth-abundant, and ultra-low noble metal-containing, e.g., platinum group metal (PGM)-containing, electrocatalyst materials for anodic hydrogen oxidation reaction (HOR). The electrocatalyst materials include metal silicide alloy-based solid solutions of the general formula: (A.sub.(n-x)B.sub.x)Si.sub.y, wherein A is a transition metal element or mixture or alloy thereof, B is a noble metal element or mixture or alloy thereof, and each of n and x, is a positive integer or a positive fractional number, and y is a positive integer.

An electrode for use in an electrochemical cell, especially a zinc-bromine flow battery or a hydrogen/bromine flow battery, and methods for manufacturing and using the electrode is provided. The electrode has a metal substrate and a catalytic coating applied onto the substrate wherein the catalytic coating has a Ru-rich mixture of ruthenium and having 70-80 mol % Ru, 1-5 mol % Pt and 17-25 mol % Ir. The catalytic coating composition exhibits a surprisingly high voltage efficiency and operating lifetime despite its relatively low Ir/Ru and Pt/Ru ratios. The underlying metal substrate is for example a porous Ti layer or a layer with titanium suboxides Ti.sub.xO.sub.y.

A specific method for preparing platinum particles grafted with proton-conducting polymers and use of these particles as catalysts for oxygen reduction.

A method for preparing a supported noble metal catalyst, comprising: i) melting a noble metal sponge, a peroxide, and a support and/or a support precursor together; ii) dispersing the molten mixture in water; and iii) adjusting the pH to 4 to 10, thereby obtaining a supported noble metal catalyst. The method uses a noble metal sponge rather than an intermediate noble metal precursor, such as a noble metal nitrate salt, a noble metal halide salt, a halogenated noble metal acid, or a salt of the halogenated noble metal acid, for example, H.sub.3IrCl.sub.6, H.sub.2IrCl.sub.6, or IrCl.sub.3. The method does not produce any intermediate product, and does not use any chlorine-containing material, thereby avoiding contamination of the final catalyst by chlorine. The catalyst produced by the present invention has high activity, high surface area, and the RDE OER overpotential is less than 230 mV (at 10 mA cm.sup.2).

A method for fabricating a polymeric material for use in an energy storage apparatus, a polymeric material, and an energy storage apparatus including the polymeric material, where the polymeric material includes a polymer arranged to combine with a plurality of chemical ions so as to form an ion-conducting material, wherein the ion-conducting material is in solid-state.

The present invention provides a catalyst comprising a layer of metallic palladium implanted with an inert gas ions, an electrochemical system containing thereof, a palladium-inert gas alloy stable in the normal conditions, use thereof and a fuel cell containing thereof.

The present invention relates to a non-platinum catalyst for an oxygen reduction electrode, in which iron nanoparticles are dispersed in nitrogen-doped mesoporous carbon nanofibers, and the surfaces of the iron nanoparticles are at least partially exposed to the outside. In addition, the present invention relates to a method for producing a non-platinum catalyst for an oxygen reduction electrode using electrospinning and hydrogen activation reactions.

Provided is a humidity responsive energy harvester. The humidity responsive energy harvester may include: a substrate structure including a carbon fiber; a first harvesting structure disposed on the substrate structure and including a polymer that changes a concentration of hydrogen ions in response to humidity; and a second harvesting structure disposed on the first harvesting structure and including a carbon fiber coated with an active material which includes a composite of a transition metal and an oxide of the transition metal, wherein when the polymer in the first harvesting structure changes the concentration of hydrogen ions in response to the humidity, energy may be generated due to a difference in redox reaction of the second harvesting structure.