Abstract: Methods and devices for catalyzing reactions, e.g., in a metal-air electrochemical cell, are disclosed. In some instances, a porous positive electrode of the metal-air electrochemical cell includes a metal to catalyze a reaction at the electrode (e.g., oxidation of one or more metal-oxide species). The metal can be disposed as nanoparticles, and/or be combined with a second metal. Other aspects are directed to devices and methods that can generally promote a chemical reaction (e.g., an oxidation/reduction reaction) such as the formation of platinum containing nanoparticles that can be used to catalyze electrochemical reactions.

Abstract: The present invention relates to single chamber fuel cells and systems and methods associated with the same. Architectures and materials that allow for high performance, enhanced fuel utilization, mechanical robustness, and mechanical flexibility are described. In some embodiments, multiple fuel cell units are arranged in a single chamber and may be, in some cases, connected to each other (e.g., connected in series, connected in parallel, etc.). Each fuel cell unit can be defined as one or more anode(s), one or more cathode(s), and an electrolyte able to maintain electrical separation between the anode(s) and cathode(s). The multiple fuel cell units are arranged in stacks in some cases. In one set of embodiments, the stacks of fuel cell units can be shaped and/or arranged to enhance the mixing of fuel and oxidant, thus improving distribution of reactants in the reaction zone. For example, the stacks of fuel cells may be arranged as fins within the fuel cell chamber.

Abstract: The embodiments described herein relate generally to methods, compositions, articles, and devices associated with layer-by-layer assembly and/or functionalization of carbon-based nanostructures and related structures. In some embodiments, the present invention provides methods for forming an assembly of carbon-based nanostructures on a surface. The carbon-based nanostructure assembly may exhibit enhanced properties, such as improved arrangement of carbon-based nanostructures (e.g., carbon nanotubes) and/or enhanced electronic and/or ionic conductivity and/or other useful features. In some cases, improved properties may be observed due to the attachment of functional groups to the surfaces of carbon-based nanostructures. Using methods described herein, formation of carbon-based nanostructure assemblies may be controlled to produce structures with enhanced properties.

Abstract: Fiber structures that include a catalytic material are provided. The fiber structures (e.g., membranes) may be formed of interconnected carbon fibers. The catalytic material may be in the form of nanosize particles supported on the fibers. In one method of the invention, the structures are produced by electrospinning a polymeric material fiber structure that is subsequently converted to a carbon fiber structure in a heat treatment step which also causes the catalytic material particles to nucleate on the carbon fibers and grow to a desired size. The catalytic material may be uniformly distributed across the carbon fiber structure and the amount of catalytic material may be controlled. These factors may enhance catalytic performance and/or enable using less catalytic material for equivalent catalytic performance which can lead to cost savings, amongst other advantages. The fiber structures may be used in a variety of applications including electrodes in batteries and fuel cells.

Abstract: Fiber structures that include a catalytic material are provided. The fiber structures (e.g., membranes) may be formed of interconnected carbon fibers. The catalytic material may be in the form of nanosize particles supported on the fibers. In one method of the invention, the structures are produced by electrospinning a polymeric material fiber structure that is subsequently converted to a carbon fiber structure in a heat treatment step which also causes the catalytic material particles to nucleate on the carbon fibers and grow to a desired size. The catalytic material may be uniformly distributed across the carbon fiber structure and the amount of catalytic material may be controlled. These factors may enhance catalytic performance and/or enable using less catalytic material for equivalent catalytic performance which can lead to cost savings, amongst other advantages. The fiber structures may be used in a variety of applications including electrodes in batteries and fuel cells.