# US 5,350,727 A · Process of preparing catalyst supporting highly dispersed platinum particles

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- Number: US 5,350,727 A
- Document ID: US5350727A
- Status: Granted
- Kind: A
- Application number: 08/088,082
- Filed: 1993-07-06
- Granted: 1994-09-27
- Earliest claimed: 1992-07-06
- Assignees: Tanaka Kikinzoku Kogyo K.K.; Stonehart Associates Inc.
- Inventors: Kazunori Tsurumi; Paul Stonehart
- Web page: https://patentgrep.com/patent/US5350727A

## CPC

- H01M 4/926: {on carbon or graphite}
- B01J 23/42: Platinum
- B01J 37/0211: {using a colloidal suspension}
- B01J 37/031: {Precipitation}
- H01M 4/92: Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence)
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Disclosed herein is a process of preparing a catalyst having narrow particle size distribution and supported with monodispersed platinum particles of which a particle size is about less than 20 .ANG.. In the present invention, allyl alcohol and hydrazinc hydrate are employed in place of a sulfur-containing agent for supporting the platinum particles on a support thereby avoiding the contamination of the sulfur component and the high temperature treatment for decomposing the sulfur-containing agent. Accordingly, the resulting catalyst contains no sulfur contaminant and substantially no agglomerated platinum particles.

## Claims

### Claim 1

A process of preparing a catalyst, which comprises highly dispersed platinum particles, said process comprising the steps of:
a. preparing a platinum containing solution by dissolving dinitrodiamine platinum in nitric acid;
b. adding a supporting material for said platinum particles, in the catalyst, to the platinum containing solution;
c. adding allyl alcohol and hydrazine hydrate to the platinum containing solutions; wherein a platinum containing reaction product of the dissolved dinitroamine platinum, the allyl alcohol and the hydrazine hydrate is deposited on said supporting material; and
c. thermally treating the supporting material in a hydrogen-containing reduction gas, to reduce the reaction product to the platinum particles.