# US 11,998,903 B2 · Method for producing catalysts with nanoparticles of platinum and its alloys with metals

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- Number: US 11,998,903 B2
- Document ID: US11998903B2
- Status: Granted
- Kind: B2
- Application number: 16/942,364
- Filed: 2020-07-29
- Published: 2021-01-14
- Granted: 2024-06-04
- Earliest claimed: 2020-07-29
- Assignees: ZeroAvia, Inc.
- Applicants: ZeroAvia, Inc.
- Inventors: Anastasia Anatolyevna Alekseenko; Sergey Valerievich Belenov; Vladimir Efimovich Guterman
- Web page: https://patentgrep.com/patent/US11998903B2

## CPC

- B01J 37/348: {Electrochemical processes, e.g. electrochemical deposition or anodisation}
- C25B 11/081: the element being a noble metal
- B01J 23/42: Platinum
- B01J 35/45: Nanoparticles
- C25B 9/17: Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
- C25B 11/054: Electrodes comprising electrocatalysts supported on a carrier
- C25B 11/093: at least one noble metal or noble metal oxide and at least one non-noble metal oxide
- C25B 11/097: comprising two or more noble metals or noble metal alloys
- H01M 4/885: {followed by reduction of the catalyst salt precursor}
- H01M 4/921: {Alloys or mixtures with metallic elements}
- H01M 4/925: {supported on carriers, e.g. powder carriers}
- H01M 4/926: {on carbon or graphite}
- B01J 21/185: {Carbon nanotubes (carbon nanotubes per se C01B32/15)}
- B01J 35/61: Surface area
- B01J 2235/00: Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties
- B01J 2235/15: X-ray diffraction
- B01J 2235/30: Scanning electron microscopy; Transmission electron microscopy
- Y02E 60/50: Fuel cells
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The method allows to produce catalysts with nanoparticles of platinum and its alloys with metals of a given composition, with high values of catalytic activity in an oxygen electroreduction reaction, and with predetermined values of structural characteristics. The method comprises preparation of a solution of chloroplatinic acid or a mixture of chloroplatinic acid with metal salts, mixing thereof with dispersed carbon or non-carbon carriers, their mixtures and compositions with specific surface area of more than 60 m2/g, dispersion of the obtained mixture, chemical reduction of compounds of platinum and a metal salt with subsequent deposition of nanoparticles of metallic platinum or its alloys on a dispersed carrier being carried out by purging gases selected from: nitrogen oxides (N2O, NO, NO2), carbon oxides (CO, CO2), sulfur oxide (SO2), ammonia (NH3) or their mixtures through the solution at a temperature of the solution in the range from 5 to 98° C.

## Claims

### Claim 1

A method for producing catalysts with nanoparticles of platinum or its alloys with metals, for a cathode and an anode of low-temperature fuel cells and electrolyzers, wherein each alloy comprises platinum and at least one metal, comprising:
preparation of a solution of chloroplatinic acid or a mixture of chloroplatinic acid with at least one metal salt in water or in an aqueous organic solvent;
mixing thereof with dispersed carbon or non-carbon carriers, or their mixtures, or compositions with specific surface area of more than 60 m2/g;
dispersing the obtained mixture to obtain a suspension;
alkalizing to a pH between 6 and 11 of said suspension;
wherein gas selected from the group consisting of: nitrogen oxides, carbon dioxide (CO2), sulfur oxide (SO2), ammonia (NH3), and their mixtures is purged through the obtained suspension at a temperature of the obtained suspension in a range from 5 to 98° C., to produce said catalysts with nanoparticles of platinum or its alloys with metals, and wherein said catalysts are suited for said cathode and said anode of said low-temperature fuel cells and said electrolyzers, wherein nitrogen oxides are N2O, NO, and NO2; and
adjusting a time interval occurring between said preparation of said solution of chloroplatinic acid or said mixture of chloroplatinic acid with said at least one metal salt in said water or in said aqueous organic solvent and when said selected gas is purged therethrough, to produce said catalysts with said nanoparticles of platinum or its alloys with metals, for said cathode and said anode of said low-temperature fuel cells and electrolyzers.