A composite electrode includes two or more types of fibers forming a fiber network, comprising at least a first type of fibers and a second type of fibers. The first type of fibers comprises a first polymer and a first type of particles. The second type of fibers comprises a second polymer and a second type of particles. The second polymer is same as or different from the first polymer. The second type of particles are same as or different from the first type of particles.

A method for preparing a catalyst for a fuel cell including performing a first supporting; separating particles unsupported in the first supporting; heat treating; and performing a second supporting, and a catalyst for a fuel cell prepared using the same.

A proton conductor is in contact with a catalyst containing platinum. The proton conductor includes a cationic organic molecule, a metal ion, and an oxoacid anion. A protic ionic liquid containing the cationic organic molecule and the oxoacid anion is coordinated to the metal ion to form a coordination polymer.

An electrolyzer system includes an anticorrosive, conductive material including a first oxide having oxygen vacancies and a formula (Ia): MgTi.sub.2O.sub.5-δ (Ia), where δ is any number between 0 and 3 including a fractional part denoting the oxygen vacancies; and a second oxide having a formula (II): Ti.sub.aO.sub.b (II), where 1<=a<=20 and 1<=b<=30, optionally including a fractional part, the first and second oxides of formulas (Ia) and (II) forming a polycrystalline matrix within the electrolyzer system.

Disclosed are an electrolyte membrane for fuel cells that can prevent poisoning of catalysts and a method of producing the same. The electrolyte membrane for fuel cells includes an ion transport layer including an ionomer having proton conductivity, and a catalytic composite dispersed in the ion transport layer, wherein the catalytic composite includes a catalytic particle including a catalytic metal component having an activity of decomposing hydrogen peroxide, and a protective layer formed on at least a part of a surface of the catalytic particle to prevent the ionomer from contacting the catalytic metal component.

A fuel cell membrane electrode assembly includes a polymer electrolyte membrane and a pair of electrocatalyst layers arranged to have the polymer electrolyte membrane therebetween, at least one of the pair of electrocatalyst layers includes particles supporting a catalyst which is composed of a noble metal component, a polymer electrolyte, and a fibrous oxide-based catalytic material, and the fibrous oxide-based catalytic material includes at least one transition metal element selected from a group consisting of Ta, Nb, Ti, and Zr.

Disclosed herein is a multi-layered composite thin film material formed from graphene quantum dots (GQDs) and metal nanocrystals in a layer-by-layer design, wherein the metal nanocrystals can be selected from the group consisting of Ru, Rh, Os, Ir, Pd, Au, Ag and Pt. In a preferred embodiment, the multi-layered composite thin film material is prepared via a facile, green, and easily accessible layer-by-layer (LbL) self-assembly strategy. In this strategy, positively charged GOQDs and negatively charged metal nanocrystals are alternately and uniformly integrated with each other in a “face-to-face” stacked fashion under substantial electrostatic attractive interaction, and then the obtained GOQDs/metal composite thin film is calcined into GQDs/metal composite thin film. The composite thin film material disclosed herein may be used to catalyse a wide range or reactions, including selective reduction of aromatic nitro compounds in water and electrocatalytic oxidation of methanol at ambient conditions.

A fuel cell catalyst system includes a catalyst and a catalyst support material binding the catalyst and including an anticorrosive, conductive material having oxygen vacancies and a formula (I):
MgTi.sub.2O.sub.5-δ  (I),
where
.sub.δ is any number between 0 and 3 optionally including a fractional part denoting the oxygen vacancies, the material having an electronic conductivity of about 2-10 S/m at room temperature in an ambient environment.

Disclosed is a catalyst complex for a fuel cell. The catalyst complex includes a support including carbon (C), platinum (Pt) supported on the support, and an iridium (Ir) compound supported on the support, and the iridium compound includes at least one of iridium oxide represented by Chemical Formula 1, IrO.sub.x, and iridium-transition-metal oxide represented by Chemical Formula 2, IrMO.sub.x, wherein M is a transition metal selected from the group consisting of Fe, Co, Cu, Ni and combinations thereof, and x is from 1 to 2.

A fuel cell bipolar plate (BPP) includes a metal substrate having a bulk portion and a surface portion comprising an anticorrosive, conductive material having oxygen vacancies and a formula (I):
MgTi.sub.2O.sub.5-δ  (I),
where .sub.δ is any number between 0 and 3 optionally including a fractional part denoting the oxygen vacancies, the material having an electronic conductivity of about 2-10 S/m at room temperature in an ambient environment.