Abstract: A composite material having utility for removing sulfur from a feedstock comprises a ceramic matrix having a relatively low melting point metal such as tin, zinc, lead or bismuth nanodispersed therein. The material may be prepared from a mixture of particles of a precursor of the ceramic matrix and precursor of the metal. The precursors are selected such that the melting point of the precursor of the ceramic is less than the melting point of the precursor of the metal. The mixture of precursor materials is heated to a temperature sufficient to melt the precursor of the ceramic material so as to coat it onto the precursor of the metal. The ceramic precursor is then reacted so as to convert it to a ceramic. Thereafter, the precursor of the metal is converted to a free metal which is retained within the ceramic matrix so as to prevent agglomeration.

Abstract: In a method of producing a particulate electrocatalyst composition, a precursor medium comprising at least a first metal precursor, a liquid vehicle, and a substrate precursor to substrate particles is atomized into precursor droplets. The droplets are then heated to a reaction temperature of not greater than 700° C. to form composite particles comprising said first metal at least partly in an oxide form dispersed on said substrate particles. The composite particles are then collected and are heated at a first treatment temperature no greater than 250° C. in the presence of a reducing atmosphere to at least partly convert said oxide form to the metal.

Abstract: A composite material having utility for removing sulfur from a feedstock comprises a ceramic matrix having a relatively low melting point metal such as tin, zinc, lead or bismuth nanodispersed therein. The material may be prepared from a mixture of particles of a precursor of the ceramic matrix and precursor of the metal. The precursors are selected such that the melting point of the precursor of the ceramic is less than the melting point of the precursor of the metal. The mixture of precursor materials is heated to a temperature sufficient to melt the precursor of the ceramic material so as to coat it onto the precursor of the metal. The ceramic precursor is then reacted so as to convert it to a ceramic. Thereafter, the precursor of the metal is converted to a free metal which is retained within the ceramic matrix so as to prevent agglomeration.

Abstract: An electrocatalyst ink composition comprising a liquid vehicle, particles comprising at least one electrocatalyst metal, and at least one copolymer dispersant comprising at least one polyalkylene oxide segment.

Abstract: A membrane electrode assembly comprises (a) a solid electrolyte polymer membrane; (b) an anode electrocatalyst layer disposed at one surface of the membrane and comprising a first electrocatalyst composition comprising carbon substrate particles and nanoparticles comprising an alloy of platinum and ruthenium disposed on the surface of the substrate particles; (c) a cathode electrocatalyst layer disposed at an opposite surface of the membrane, the cathode layer comprising a second electrocatalyst composition different from the first electrocatalyst composition and comprising carbon substrate particles and nanoparticles comprising platinum disposed on the surface of the substrate particles; and (d) gas diffusion layers disposed over each of the anode and cathode electrocatalyst layers.

Abstract: In a method of producing a particulate electrocatalyst composition, a precursor medium comprising at least a first metal precursor, a liquid vehicle, and a substrate precursor to substrate particles is atomized into precursor droplets. The droplets are then heated to a reaction temperature of not greater than 700° C. to form composite particles comprising said first metal at least partly in an oxide form dispersed on said substrate particles. The composite particles are then collected and are heated at a first treatment temperature no greater than 250° C. in the presence of a reducing atmosphere to at least partly convert said oxide form to the metal.

Abstract: A process for the activation of a membrane electrode assembly, such as a direct methanol fuel cell membrane electrode assembly, with a hydrocarbon fuel, e.g., an alkanol fuel such as methanol, and an oxidant is described. The process comprises repeatedly applying an increasing or decreasing potential in each of a plurality of cycles over a voltage range of at least 0.1 volts, e.g., at least 0.2 volts or at least 0.3 volts, until the membrane electrode assembly is substantially activated. The cycles optionally are organized in cycle sets with rest periods therebetween. The temperature at which the cycles are run optionally is increased or decreased in a respective cycle set.

Abstract: An electrocatalyst ink composition comprising a liquid vehicle, particles comprising at least one electrocatalyst metal, and at least one copolymer dispersant comprising at least one polyalkylene oxide segment.

Abstract: A catalyst is synthesized by a method in which a catalytic metal such as platinum or another noble metal is dispersed onto a support member. A transition metal macrocycle is also adsorbed onto the support, and the support is heat treated so as to at least partially pyrolyze the macrocycle and anchor the transition metal to the support. The catalytic metal is alloyed with the transition metal either during the pyrolysis step, or in a separate step. The catalyst has significant utility in a variety of applications including use as an oxygen reduction catalyst in fuel cells.

Abstract: A catalyst is synthesized by a method in which a catalytic metal such as platinum or another noble metal is dispersed onto a support member. A transition metal macrocycle is also adsorbed onto the support, and the support is heat treated so as to at least partially pyrolyze the macrocycle and anchor the transition metal to the support. The catalytic metal is alloyed with the transition metal either during the pyrolysis step, or in a separate step. The catalyst has significant utility in a variety of applications including use as an oxygen reduction catalyst in fuel cells.

Abstract: A proton exchange membrane for a fuel cell is prepared from a polyimidazole polymer having the formula: wherein R1-R3 are independently H, a halogen, an alkyl or a substituted alkyl. X1 and X2 are independently or an electron withdrawing group such as CN. The membrane may be doped to alter its conductivity. The membrane may be prepared from a copolymer of the polyimidazole. Also disclosed is a fuel cell incorporating the membrane.

Abstract: A proton exchange membrane for a fuel cell is prepared from a polyimidazole polymer having the formula: 1