33results about How to "Low platinum loading" patented technology

Nanoparticles which contain noble metals alone or noble metals in combination with base metals. The nanoparticles are embedded in an aqueous solution of a temporary stabilizer based on a polysaccharide.

A method for forming a patterned noble metal coating on a gas diffusion medium substantially free of ionomeric components comprising subjecting an electrically conductive web with a patterned mask overlaid thereto to a first ion beam having an energy not higher than 500 eV, and to a second beam having an energy of at least 500 eV, containing the ions of at least one noble metal and a gas diffusion electrode.

The invention belongs to the technical field of new energy materials and applications, and in particular relates to a method for preparing a platinum-cobalt alloy catalyst. The preparation method of the platinum-cobalt alloy catalyst of the invention comprises the following steps: preparation of a catalyst precursor, high-temperature reduction of the precursor, high-temperature alloying of the catalyst, pickling of the catalyst and water washing of the catalyst. The present invention uses pure water as a solvent, which has safety and environmental protection issues; when the precursor is reduced at high temperature, the reducing agent is the carbon in platinum carbon, and no additional reducing agent is needed, which avoids the use of sodium borohydride or hydrazine hydrate, etc. Safety and environmental protection problems caused by toxic reagents; Gel is used as the precursor of platinum-cobalt alloy to prepare platinum-cobalt alloy oxygen reduction catalyst, which ensures the simultaneous reduction of platinum and cobalt; no sodium salt and chloride ions are added, which reduces the difficulty of product post-processing The present invention uses ammonia water to adjust the pH value of the system, and the post-treatment steps are simple; the transition metal cobalt is added to the platinum-carbon catalyst, which reduces the platinum loading of the catalyst while improving the performance of the catalyst.

The invention discloses a platinum / alumina catalyst. The platinum / alumina catalyst is prepared from components in percentage by mass as follows: 0.05%-1.0% of platinum, 0.1%-2.0% of iron, 0.5%-5.0% ofgermanium dioxide and 92.0%-99.35% of alumina. The invention also discloses a preparation method of the platinum / alumina catalyst and an application of the platinum / alumina catalyst in synthesis of an anti-aging agent 4020 from the platinum / alumina catalyst, N-phenyl p-phenylenediamine and methyl isobutyl ketone in a fixed bed reactor. Compared with the prior art, the platinum / alumina catalyst has mild application conditions, high activity, high selectivity, long service life and relatively low price, is simple to produce and easy to industrialize and has bright application prospects and enormous economic benefits.

The invention belongs to the technical field of dye sensitized solar cells, in particular to a method for preparing a graphene / platinum nano counter electrode material for a dye sensitized solar cell. The method comprises the following steps of: soaking a conducting substrate on which a polyelectrolyte is adsorbed in a graphene suspension, a polyelectrolyte solution and a chloroplatinic acid solution in sequence in an electrostatic self-assembly way to form a self-assembly ultrathin film with a polyelectrolyte / graphene / polyelectrolyte / chloroplatinic acid structure on the surface of the conducting substrate under the action of electrostatic attraction; and sintering and transforming into a 'graphene / platinum nanoparticle' ultrathin film. The film can be taken as a counter electrode material for the dye sensitized solar cell. The preparation method has a simple process, the prepared counter electrode has extremely low platinum load amount, the cost of the counter electrode and the dye sensitized solar cell is greatly lowered, and the method can be applied to large-scale production of assembly line operation.

Using self-assembly technique loads Nano granules of platinum in hydrosol of compositive Nano platinum to surface of conducting substrate of containing mercaptan functional group after modification of L-B membrane or silanization so as to realize even, tight and discontinuous distribution of Nano granules of platinum on surface of conducting substrate. Using high sintering or vacuum treatment in low temperature forms Nano platinum carried catalysis electrode in high chemical activity. Electrode produced in the invention possesses very low platinum load so as to lower cost for preparing solar battery. The invention is applicable to preparation of flexible electrode, especially suitable to electrode pair in Nano crystal sensitized solar battery.

The invention relates to a method for carrying out surface alloy modification upon nano-grade porous gold. According to the method, an alloy material is deposited on the surface of nano-grade porous gold with a pulse potential method. The method has the steps that: the nano-grade porous gold is connected on an electrode, and is placed in a solution with different metal ions; pulse potential is applied, wherein the pulse skips between a high potential and a low potential; the high potential is fixed at a value with which the different metal ions are not reduced, and the low potential is fixed at a value with which the metal ions in the solution can be reduced; the two potentials form a pulse cycle; and through multiple times of cycles, the alloy modification upon the nano-grade porous gold is completed. With the method, the nano-grade porous gold is subjected to alloy modification. The prepared nano-grade porous gold based catalyst has low platinum load, high activity, high intoxication resistance, and high corrosion resistance.

The invention relates to a preparation of a platinum catalyst of a direct methanol fuel cell, which adopts a method of electrodepositing and carries out pulse electrodepositing on platinum by two steps, namely a larger current is adopted for forming a crystal nucleus in step I; a small current is adopted for the growing the crystal nucleus in step II; the grain diameter of the prepared catalyst can be reduced through changing the applied electric signal; thereby leading the formed platinum grains to be more dispersive and have a higher covering rate and a larger specific surface; thereby reducing the platinum loading capacity of unit area of the electrodes, improving utilization rate and activity and simultaneously reducing the cost of the catalyst. The method is simple and controllable to be applied. The prepared platinum catalyst can not only be applied to the direct methanol fuel cell, but also can be applied to other fuel cells as catalysts. Besides, the method can be expanded andapplied to platinum-ruthenium codeposition and other multi-metal codeposition.