To spread the use of catalysts for fuel cells, there is a demand to develop a catalyst that uses less Pt and has a high power generation efficiency. An electrode catalyst includes a support particle containing a metal oxide and a precious-metal alloy supported on the support particle. The support particle includes multiple branches, a hole between the branches, and a pore. The pore is surrounded by the branches and the hole. The precious-metal alloy includes a precious metal element and at least one or more transition elements.

Provided is a method for producing a catalyst, including: (i) mixing a core metal salt that serves as a material for a core metal, and a complexing agent (a) to produce a core metal complex solution containing a core metal complex; (ii) mixing a shell metal salt that serves as a material for a shell metal, and a complexing agent (b) to produce a shell metal complex solution containing a shell metal complex; (iii) mixing a carbon powder and a dispersing agent to produce a carbon powder dispersion; (iv) mixing the core metal complex solution, the shell metal complex solution, and the carbon powder dispersion, and reducing the core metal complex and the shell metal complex on the carbon powder by using at least one reducing agent; and (v) drying and baking at a predetermined temperature the carbon powder resulting from Step (iv), said carbon powder having a core-shell structure that includes the core metal and the shell metal.

Provided are processes for preparing a thermodynamically stable PtBi.sub.2 alloy nanoparticle. In certain aspects, the process comprises preparing an aqueous mixture, with the aqueous mixture comprising: an inorganic compound comprising SnCl.sub.2; an inorganic compound comprising Bi; and HCl. The process further comprises adding PtCl.sub.4 to the mixture. The process results in the spontaneous reduction of Bi and Pt. Excess SnCl.sub.2 is adsorbed as a ligand at the surface of the PtB.sub.2 alloy nanoparticle, which serves to stabilize the nanoparticle. Another aspect provides a thermodynamically stable PtBi.sub.2 nanoparticle. The nanoparticle comprises a core comprising a PtBi.sub.2 alloy. The nanoparticle further comprises a shell at least partially encapsulating the core, with the shell comprising stannous chloride. The thermodynamically stable PtB.sub.2 nanoparticle has a negative charge.

The present invention refers to a method of treating a platinum-alloy catalyst, comprising the steps of: A) providing a platinum-alloy catalyst, which comprises platinum (Pt) and at least one metal (M), which is less noble than platinum; B) exposing the catalyst to an acidic or basic medium, and exposing the catalyst to an adsorptive gas, wherein during step B) the catalyst is not subjected to an external electrical current or voltage. Further, the invention refers to a treated platinum-alloy catalyst. Moreover, and a device for carrying out the method of treating the platinum-alloy catalyst is provided.

A composite including: a carbonaceous material; and a solid solution including a first metal and a cerium oxide, wherein the solid solution is disposed on the carbonaceous material.

A core-shell catalyst with high platinum mass activity for a short period of time. The method for producing a core-shell catalyst may comprise a core containing palladium and a shell containing platinum and coating the core, the method comprising: a step of preparing a copper-coated palladium-containing particle dispersion in which copper-coated palladium-containing particles are dispersed, the particles being palladium-containing particles coated with copper; a step of preparing a platinum ion-containing solution; a step of preparing a microreactor; and a substitution step of forming the shell by substituting the copper on the copper-coated palladium-containing particle surface with platinum by mixing the copper-coated palladium-containing particle dispersion and the platinum ion-containing solution in the microreactor.

A fuel cell system includes a first fuel cell having an electrode area made of first electrode material, and a second fuel cell having an electrode area made of second electrode material having low durability against output voltage variation in comparison with the first electrode material. The fuel cell system is configured to supply electrical power to a motor generator. The fuel cell system includes a required electrical power acquisition unit configured to obtain required electrical power of the motor generator, and a control unit configured to control the second fuel cell in a manner that a variation of output electrical power of the second fuel cell becomes not more than a predetermined limit variation, and control the first fuel cell in accordance with the required electrical power and output electrical power of the second fuel cell.

A proton exchange membrane and a membrane electrode assembly for an electrochemical cell such as a fuel cell are provided. A catalytically active component is disposed within the membrane electrode assembly. The catalytically active component comprises particles containing a metal oxide such as silica, metal or metalloid ions such as ions that include boron, and a catalyst. A process for increasing peroxide radical resistance in a membrane electrode is also provided that includes the introduction of the catalytically active component described into a membrane electrode assembly.

A hydrogen/bromine reduction-oxidation flow battery system includes a bromine electrode, a hydrogen electrode, a membrane, a first catalyst, and a second catalyst. The membrane is positioned between the bromine electrode and the hydrogen electrode. The first catalyst is associated with the bromine electrode. The second catalyst is associated with the hydrogen electrode and at least partially formed from a subsurface alloy configured (i) to promote facile dissociation of H.sub.2, and (ii) to prevent bromide from adsorbing onto the hydrogen electrode.

Disclosed is a method of manufacturing a ternary catalyst for an oxygen reduction reaction. The method may include constructing a database including catalytic activity of oxygen reduction reaction (ORR) of PtFeCu nanoparticles using machine-learning-based neural network potential (NNP), determining thermodynamically stable PtFeCu nanoparticles through Monte Carlo calculation, and selecting a type of the PtFeCu nanoparticles by analyzing a structure of PtFeCu nanoparticles.