56 results about "Mass activity" patented technology

The present application is directed to a fabrication method to reduce Pt loading in fuel cells through the use of thin film electrodes by increasing Pt utilization and the use of more active Pt alloys that can be easily and inexpensively fabricated by sputter deposition. Pt and Pt alloy thin films were sputter deposited onto carbon / Nafion® decals and subsequently hot pressed with the catalyst thin film towards the membrane. The results show improved mass performance and catalyst utilization with Pt thin films and increased mass activities can be achieved with PtCo (76:24 atomic ratio) and PtCr (80:20 atomic ratio) as compared to pure Pt. Mass activity improvements of 14 mV and 8 mV were observed for the PtCo and PtCr alloys with respect to a pure Pt film with similar mass loading under 300 / 350 kPa hydrogen / oxygen operation.

The invention provides a fuel cell electrode catalyst capable of greatly reducing the use of Pt in PtCo alloy and obtaining PtCo / C which can achieve a mass activity equal to that of a Pt / C catalyst or above, and a manufacturing method thereof, a supporting electrode of the fuel cell electrode catalyst, and a fuel cell. The fuel cell electrode catalyst supports the alloy on a carbon support, the alloy comprises a noble metal and a base metal, wherein the molar ratio of the noble metal to the base metal of the above alloy, referring to the ratio of the base metal / the noble metal is set as 4-9.

The invention provides a metal material for a proton exchange membrane fuel cell cathode catalyst. An alloy formed by platinum and gallium has a one-dimensional nanowire structure having the length of40-80nm and the diameter of 1-2nm, is provide. The invention also provides a preparation method of the metal material. Firstly Pt nanowires are obtained by reduction of the divalent metal platinum under the organic liquid condition, and a trivalent metal gallium compound and a reducing agent are added into the Pt nanowires and the alloy of Pt and Ga with the one-dimensional nanowire structure isobtained through reduction reaction. The structure of the Pt-Ga alloy material is the one-dimensional nanowire structure, the mass activity of the catalyst supported by carbon is more than nine timesof that of the Platinum-carbon nano-catalyst, the area activity of the catalyst is more than seven times than that of the Platinum-carbon nano-catalyst and the mass activity performance loss of the catalyst is only 15.7% when it is recycled 30000 times in oxygen atmosphere. Besides, the preparation method can realize high content doping of Ga element to Pt nanowires and the content is controllable, the use of the Pt element can be effectively reduced according to the requirements and the battery cost can be reduced; meanwhile, the reaction condition is mild and operation is simple.

The invention provides a platinum-based monatomic electrocatalytic material as well as a preparation method and application thereof, belonging to the field of electrocatalysis. The platinum-based monatomic electrocatalytic material is prepared by taking an Anderson type heteropolyacid compound, dopamine or a salt thereof as raw materials, wherein the Anderson type heteropolyacid compound is Anderson type heteropolyacid or a hydrate thereof, and a salt of the Anderson type heteropolyacid or a hydrate thereof; and the structure of the Anderson type heteropolyacid is H8PtR6O24, and R is a transition metal. The electrocatalytic hydrogen evolution performance of the platinum-based monatomic electrocatalyst in an acid solution is equivalent to the electrocatalytic hydrogen evolution performance of commercial platinum carbon, and the electrocatalytic hydrogen evolution performance of the platinum-based monatomic electrocatalyst in an alkaline solution is remarkably higher than the electrocatalytic hydrogen evolution performance of the commercial platinum carbon. Meanwhile, the long-term durability of the platinum-based monatomic electrocatalyst in the acid solution and the alkaline solution is remarkably superior to the long-term durability of commercial platinum carbon, and the mass activity and the catalytic conversion frequency of the platinum-based monatomic electrocatalyst are also remarkably superior to the mass activity and the catalytic conversion frequency of the commercial platinum carbon. The platinum-based monatomic electrocatalyst prepared in the invention has high activity and long-term stable electrocatalytic performance in a wide pH range, and has wide application prospects.

The invention provides an alloy nanocage catalyst, and a preparation method and an application thereof. The catalyst comprises an alloy of noble metal and transition metal, wherein the noble metal includes any one or a combination of at least two of palladium, ruthenium, platinum, gold, rhodium, osmium and iridium; the transition metal includes copper; and the catalyst is of a hollow nanocage structure. According to the catalyst, the transition metal part is used for replacing the noble metal to form the alloy, so that the usage amount of the noble metal is reduced, the noble metal and the transition metal have a synergistic effect, an electronic structure is optimized, and the catalyst stability is enhanced; the catalyst has an octahedral hollow cage-like structure and is stable in structure and large in specific surface area, the usage amount of the noble metal is small, the catalyst cost is greatly reduced, and the application prospect is good; the catalyst is applied to the fuel cell positive catalysis; and the noble metal has the mass activity which can reach about 1,000mA mg<-1>, and the specific activity which can reach about 2.0mA cm<-2>.

The invention discloses a three-dimensional carbon structure loaded GaN catalyst and a preparation method thereof, and belongs to the technical field of fuel cell catalysts. The method comprises the following steps: 1) carrying out a pretreatment process on carbon-based materials with various structures to obtain three-dimensional carbon structure powder; 2) performing plasma treatment on the three-dimensional structure carbon powder to obtain surface-activated three-dimensional structure carbon powder; 3) preparing a GaN nano material by adopting a microwave plasma chemical vapor deposition system; 4) transferring the GaN nano material to the surface of the foamed nickel electrode, and performing electrostatic adsorption on the three-dimensional carbon structure in an aqueous solution; and 5) annealing the three-dimensional carbon structure adsorbing the GaN nano material to obtain the three-dimensional carbon structure loaded GaN catalyst. The mass activity of the prepared three-dimensional carbon structure loaded GaN catalyst is larger than 100 mA / mgGaN at 0.9 V, and after 10000 circles of aging tests, the mass activity attenuation of the three-dimensional carbon structure loaded GaN catalyst is smaller than 20%.

The invention discloses an inorganic-organic core-shell framework loaded low-dosage precious metal palladium material and preparation thereof and application of the material in electro-catalytic dechlorination hydrogenation reaction. The preparation method comprises the following steps: polymerizing dopamine around a TiO2 one-dimensional nanorods which vertically grow on the surface of FTO and have an array structure by utilizing an in-situ auto-polymerization effect of the dopamine to form an inorganic-organic core-shell structure of TiO2 nanorod wrapped by the dopamine; and uniformly dispersing and loading an extremely low amount of palladium nanoparticles on the core-shell framework by adopting a chemical impregnation method to obtain an electrode material, wherein the loading capacity of precious metal palladium in the electrode material is only 0.29%, when the electrode material is used as a cathode to be applied to electro-catalysis of a dechlorination reaction of a chlorinated organic compound, the mass activity reaches up to 44.39 min<-1>g<-1>, the conversion rate of dechlorination of the chlorinated organic compound can reach up to 94%, very high electro-catalytic reaction activity is shown, and a relatively large application prospect is achieved in electro-catalytic hydrodechlorination.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt / C catalyst.

The invention discloses a preparation method of a platinum-based alloy catalyst, which comprises the following steps: (1) preparing nano-sized alloy particles of platinum and 3d transition metals; (2) acid-treating the alloy particles prepared in step (1) (3) annealing the alloy particles treated in step (2); the platinum-based alloy catalyst prepared by the present invention can prevent the loss of transition metals in the working environment, and realize the long-term use process of the platinum-based alloy catalyst The electrochemical active area, oxygen reduction specific activity, oxygen reduction mass activity and other properties basically remain unchanged, which ensures the long-term durable use of platinum-based alloy catalysts and is suitable for large-scale industrial production.