Abstract:
The present disclosure relates to a method and an apparatus for preparing nanosized metal or alloy nanoparticles by depositing metal or alloy nanoparticles with superior size uniformity on the surface of a powder as a base material by vacuum deposition and then dissolving or melting the base material using a solvent or heat. The method solves the problems of the existing expensive multi-step synthesis method based on chemical reduction and allows effective synthesis of metal or alloy nanoparticles with very uniform size and metal or alloy catalyst nanoparticles supported on carbon at low cost.
Abstract:
Provided are a perfluorinated sulfonic acid polymer membrane having a porous surface layer, which includes a surface layer and a bottom layer present at the bottom of the surface layer, wherein the surface layer is a porous layer, and the bottom layer is non-porous dense layer, and a method for preparing the same through a solvent evaporation process.
Abstract:
A polymer electrolyte membrane fuel cell is provided. The polymer electrolyte membrane fuel cell includes a phosphoric acid-doped polyimidazole electrolyte membrane and a complex catalyst. In the complex catalyst, an alloy or mixture of a metal and a chalcogen element is supported on a carbon carrier. The polymer electrolyte membrane fuel cell exhibits further improved long-term operation, power generation efficiency, and operational stability at high temperature. The complex catalyst can be produced by a simple method.
Abstract:
The present disclosure relates to a PtAu nanoparticle catalyst heat-treated in the presence of carbon monoxide (CO) and a method for preparing same. Since the PtxAuy nanoparticle catalyst heat-treated under CO atmosphere has high Pt surface area and superior oxygen reduction reaction (ORR) activity, a high-efficiency, high-quality fuel cell can be achieved by applying the catalyst to a fuel cell.
Abstract:
Provided are a ceria-based composition having an undoped or metal-doped ceria and an undoped or metal-doped bismuth oxide, wherein the undoped or metal-doped bismuth oxide is present in an amount equal to or more than about 10 wt % and less than about 50 wt % based on the total weight of the ceria-based composition, and at least one selected from the ceria and the bismuth oxide is metal-doped. The ceria-based composition may ensure high sintering density even at a temperature significantly lower than the known sintering temperature of about 1400° C., i.e., for example at a temperature of about 1000° C. or lower, and increase ion conductivity as well.
Abstract:
Provided is poly(benzimidazole-co-benzoxazole) having polybenzimidazole to which benzoxazole units are introduced, as a polymer electrolyte material. The polymer electrolyte material has both high proton conductivity and excellent mechanical properties even when it is obtained by in-situ phosphoric acid doping. The polymer electrolyte material may substitute for the conventional phosphoric acid-doped polybenzimidazole in a polymer electrolyte membrane fuel cell, particularly in a high-temperature polymer electrolyte membrane fuel cell.
Abstract:
A polybenzimidazole based polymer in which substituted or non-substituted benzyl groups are introduced to the two nitrogen atoms of benzimidazole ring. The benzimidazole ring is not decomposed by the attack of hydroxide ions but shows excellent alkali resistance, and thus maintains high ion conductivity. The polybenzimidazole based polymers are particularly useful for not only solid alkali exchange membrane fuel cells (SAEMFC) but also various industrial fields in which polybenzimidazole based polymers are used.
Abstract:
Provided are cardo copolybenzimidazoles, a gas separation membrane using the same and a method for preparing the same. More particularly, provided are cardo copolybenzimidazoles obtained by introducing cardo groups and aromatic ether groups to a polybenzimidazole backbone, a gas separation membrane having significantly improved oxygen permeability by using the same, and a method for preparing the same. The cardo copolybenzimidazoles have improved solubility as compared to the polybenzimidazole polymers according to the related art, show excellent mechanical properties while maintaining thermal stability so as to be formed into a film shape, and provide a gas separation membrane having significantly improved gas permeability, particularly, oxygen permeability.