A composition comprised of a tin (Sn) or lead (Pb) film, wherein the film is coated by a shell, wherein the shell: (a) is comprised of an active metal, and (b) is characterized by a thickness of less than 50 nm, is discloses herein. Further disclosed herein is the use of the composition for the oxidation of e.g., methanol, ethanol, formic acid, formaldehyde, dimethyl ether, methyl formate, and glucose.

A fuel cell electrode comprises a three-dimensional porous composite structure comprising a porous structure comprising a plurality of metal ligaments and a plurality of pores; and at least one carbon nanotube structure embedded in the porous structure and comprising a plurality of carbon nanotubes joined end to end by van der Waals attractive force, wherein the plurality of carbon nanotubes are arranged along a same direction.

The invention relates to a method for fabricating nanowires and a method for fabricating an electrode of an electrochemical device. The nanowire fabrication method according to the invention comprises: a) a step of depositing, on one of the faces of the matrix comprising hole openings, at least one porous layer, having a porosity equal to or higher than 26% by volume, of nanoparticles of a conductive material having their smallest dimension at least equal to the diameter of the holes in the matrix, the nanoparticles being in electrical contact with one another, b) growing the nanowires in the holes of the matrix, and c) removing the matrix. The invention has an application in the field of electrochemical devices in particular.

The present invention is related to fuel cells and fuel cell cathodes, especially for fuel cells using hydrogen peroxide, oxygen or air as oxidant. A supported electrocatalyst (204) or unsupported metal black catalyst (206) of cathodes according to an embodiment of the present invention is bonded to a current collector (200) by an intrinsically electron conducting adhesive (202). The surface of the electrocatalyst layer is coated by an ion-conducting ionomer layer (210). According to an embodiment of the invention these fuel cells use cathodes that employ ruthenium alloys RuMe.sub.IMe.sub.II such as ruthenium-palladium-iridium alloys or quaternary ruthenium-rhenium alloys RuMe.sub.IMe.sub.IIRe such as ruthenium-palladium-iridium-rhenium alloys as electrocatalyst (206) for hydrogen peroxide fuel cells. Other embodiments are described and shown.

A plate-like porous metal body having a three-dimensional mesh-like structure and containing nickel (Ni). The content of the nickel in the porous metal body is 50% by mass or more. The porous metal body has a thickness of 0.10 mm or more and 0.50 mm or less.

A method of producing an electrochemical fuel cell device with one or more electrodes containing one or more electrocatalysts. The method involves the steps of, first, affixing a semi-permeable membrane with inhomogeneous conduction pathways to a conducting surface of a first electrode in a predetermined configuration to form a first electrode assembly. This assembly is then immersed in an electrolyte containing at least one electrochemical precursor with for forming an active electrocatalyst on the conducting surface of the first electrode when a potential is applied to the first electrode. The same process can occur with a second electrode assembly which can be joined to the first electrode assembly before or after the electrocatalyst deposition.

A miniaturized electrochemical cell and a method for making it are provided. The method includes preparing at least one inner electrode of an electron conducting or semi-conducting material M1; providing a hollow support made of an electrically insulating material M6 and having at least one internal hollow channel; depositing on the external surface of the support a layer of an electrically conducting material M2; forming a template of colloidal particles of an electrically insulating material M3, on the M2 layer; depositing a layer of an electrically conducting material M4 on the M2 layer; depositing a layer L1 of an electron conducting or semi-conducting material M5 on the M4 layer, introducing the at least one inner electrode into the at least one internal hollow channel of the obtained structure; stabilizing the structure at its two open ends with an electrically insulating material M7; and removing M2, M3, M4 and M6 materials.

Techniques for preparing an electrocatalyst include growing and immobilizing an earth-abundant metal on an MXene two-dimensional (2D) substrate using a solvothermal, hydrothermal, or electrodeposition process. The earth-abundant metal may include NiFeOOH. The earth-abundant metal may include Mn, Fe, Co, Ni, Cu, Ti, V, Cr, and a combination thereof. The earth-abundant metal may be nanoparticles. The nanoparticles may include multiple metals. The electrocatalyst may be provided for an oxygen evolution reaction. The electrocatalyst may produce a current density of 500-1000 mA/cm.sup.2 for at least 20 hours without degradation thereof.

Atomic mixed metal electrodes, including electrodes containing a conductive polymer-mixed metal complex, as well as methods of making and using the same, are disclosed. In some embodiments, the atomic mixed metal electrode can be described as a conductive polymer-coated electrode having mixed metal clusters complexed to the conductive polymer at levels of between 2 and 10 metal atoms. A method for preparing the conductive polymer-mixed metal complexes is disclosed that can deposit metal atoms one at a time into a complex with the conductive polymer, allowing for highly tailored atomic clusters. A method of oxidizing alcohols, and the application to devices such as fuel cells are also disclosed.

A process for depositing a plurality of layers of iridium on a substrate includes: contacting the substrate with an electrolyte composition including: iridium cations protons; biasing the substrate at a first potential; forming iridium on the substrate at the first potential of the substrate; disposing hydrogen on the substrate; self-terminating the forming of iridium on the substrate in response to increasing a coverage of hydrogen on the substrate; oxidizing hydrogen on the substrate by changing a potential of the substrate from the first potential to a second potential; and changing the potential of the substrate from the second potential to a third potential for forming additional iridium on the substrate to deposit a plurality of layers of iridium on the substrate, such that forming the additional iridium on the substrate occurs at the third potential in response to oxidizing the hydrogen on the substrate at the second potential.