Catalyst production method, electrode catalyst for fuel cell produced by this method, and catalyst production apparatus

Patent metadata

Field	Value
Publication number	US-9833770-B2
Application number	US-201214241626-A
Country	US
Kind code	B2
Filing date	Aug 29, 2012
Priority date	Aug 30, 2011
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A method for producing a catalyst supporting a metal or an alloy on a support, including: independently controlling a temperature of a first supercritical fluid to be first temperature, the first supercritical fluid containing a precursor of the metal or precursor of the alloy that is dissolved in a supercritical fluid; independently controlling a temperature of the support to be a second temperature higher than the temperature of the first supercritical fluid; and supplying the first supercritical fluid controlled to the first temperature to the support, to cause the metal or the alloy to be supported on the support.

First claim

The invention claimed is:

1. A method for producing a catalyst supporting a metal or an alloy on a support therein, comprising the steps of:
independently controlling a temperature of a first supercritical fluid so that the temperature of the first supercritical fluid is a first temperature by a first heat exchanger, the first supercritical fluid containing a precursor of the metal or precursor of the alloy that is dissolved in the first supercritical fluid;
independently controlling a temperature of the support so that the temperature of the support is a second temperature higher than the temperature of the first supercritical fluid; and
supplying the first supercritical fluid, the temperature of which has been controlled to be the first temperature, to the support, to cause the metal or the alloy to be supported on the support, in the supplying the first supercritical fluid, the first supercritical fluid is circulated between the first heat exchanger and the support,
the first supercritical fluid controlled to be the first temperature is supplied to the support to cause the precursor to be adsorbed on the support; and then,
the precursor is thermally decomposed at a third temperature to cause the metal or the alloy to be precipitated on the support, and
the second temperature of the support is higher than the first temperature of the first supercritical fluid, and less than the third temperature at which the precursor is thermally decomposed.

2. The catalyst production method according to claim 1 , wherein
the precursor is added to the first supercritical fluid in an amount equivalent to an amount of the precursor consumed to cause the metal or the alloy to be supported on the support.

3. The catalyst production method according to claim 1 , wherein
a difference between the first temperature of the first supercritical fluid and the second temperature of the support is set at 5° C. to 100° C.

4. The catalyst production method according to claim 1 , wherein
a difference between the second temperature of the support and the third temperature of the support is set at 20° C. to 500° C.

5. The catalyst production method according to claim 1 , wherein
the third temperature of the support is equal to or higher than a temperature at which the precursor is thermally decomposed.

6. The catalyst production method according to claim 1 , wherein
the metal is selected from the group consisting of platinum, cobalt, palladium, copper, titanium, gold, silver, ruthenium, chromium, iron, manganese, nickel, rhodium, iridium, and tin and the alloy includes two or more metals selected from the group consisting of platinum, cobalt, palladium, copper, titanium, gold, silver, ruthenium, chromium, iron, manganese, nickel, rhodium, iridium, and tin.

7. The catalyst production method according to claim 1 , wherein
the support is at least one support selected from the group consisting of carbon nanotube, carbon powder, titanium, silicon, tin, copper, titania, silica, and tin oxide.

8. The catalyst production method according to claim 1 , wherein
the first supercritical fluid is at least one supercritical fluid selected from the group consisting of carbon dioxide, and trifluoromethane (CHF 3 ).

9. An electrode catalyst for fuel cell, wherein
the electrode catalyst is produced by the catalyst production method according to claim 1 .

10. A method for producing a catalyst supporting a metal or an alloy on a support therein, comprising the steps of:
independently controlling a temperature of a first supercritical fluid so that the temperature of the first supercritical fluid is a first temperature by a first heat exchanger, the first supercritical fluid containing a precursor of the metal or precursor of the alloy that is dissolved in the first supercritical fluid;
independently controlling a temperature of the support so that the temperature of the support is a second temperature higher than the temperature of the first supercritical fluid; and
supplying the first supercritical fluid, the temperature of which has been controlled to be the first temperature, to the support, to cause the metal or the alloy to be supported on the support, in the supplying the first supercritical fluid, the first supercritical fluid is circulated between the first heat exchanger and the support,
the first supercritical fluid controlled to be the first temperature is supplied to the support to cause the precursor to be adsorbed on the support; and then,
the precursor is thermally decomposed at a third temperature to cause the metal or the alloy to be precipitated on the support, and
the third temperature of the support is higher than the second temperature of the support.

11. The catalyst production method according to claim 10 , wherein
a difference between the second temperature of the support and the third temperature of the support is set at 20° C. to 500° C.

12. A method for producing a catalyst supporting a metal or an alloy on a support therein, comprising the steps of:
independently controlling a temperature of a first supercritical fluid so that the temperature of the first supercritical fluid is a first temperature by a first heat exchanger, the first supercritical fluid containing a precursor of the metal or precursor of the alloy that is dissolved in the first supercritical fluid;
independently controlling a temperature of the support so that the temperature of the support is a second temperature higher than the temperature of the first supercritical fluid; and
supplying the first supercritical fluid, the temperature of which has been controlled to be the first temperature, to the support, to cause the metal or the alloy to be supported on the support, in the supplying the first supercritical fluid, the first supercritical fluid is circulated between the first heat exchanger and the support wherein,
a temperature of a second supercritical fluid containing an ionomer dissolved therein is independently controlled to be a fourth temperature;
the temperature of the support is independently controlled to be a fifth temperature higher than the fourth temperature of the second supercritical fluid; and
the second supercritical fluid controlled to be the fourth temperature is supplied to the support and the metal or the alloy supported on the support, to coat the support and the metal or the alloy supported on the support with the ionomer.

13. The catalyst production method according to claim 12 , wherein
a second heat exchanger for controlling the temperature of the second supercritical fluid so that the temperature of the second supercritical fluid is the fourth temperature is disposed, and the second supercritical fluid controlled to be the fourth temperature is circulated between the second heat exchanger and the support to supply the second supercritical fluid to the support.

14. The catalyst production method according to claim 12 , wherein
the ionomer is added to the second supercritical fluid in an amount equivalent to an amount of the ionomer consumed by coating the support, and the metal or the alloy supported on the support with the ionomer.

15. The catalyst production method according to claim 12 , wherein
a difference between the fourth temperature of the second supercritical fluid and the fifth temperature of the support is set at 5° C. to 100° C.

16. The catalyst production method according to claim 12 , wherein
the ionomer is at least one ionomer selected from the group consisting of perfluorocarbon sulfonate resins, aromatic polyether sulfonate resins, aromatic polyimide sulfonate resin

Assignees

• Hasegawa Shigeki
• Aizawa Satoru
• Toyota Motor Co Ltd

Inventors

• Hasegawa Shigeki
• Aizawa Satoru

Classifications

• H01M4/8803 Primary

  Supports for the deposition of the catalytic active composition (H01M4/90 takes precedence) · CPC title

• H01M4/926

  on carbon or graphite · CPC title

• H01M4/925

  supported on carriers, e.g. powder carriers · CPC title

• H01M4/9083

  on carbon or graphite · CPC title

• H01M4/8825

  Methods for deposition of the catalytic active composition · CPC title