Method for producing conductive mayenite compound powder having large specific surface area

Patent metadata

Field	Value
Publication number	US-10124319-B2
Application number	US-201615383412-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Aug 30, 2012
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

If a conductive mayenite compound having a large specific surface area is obtained, the usefulness thereof in respective applications is remarkably increased. A conductive mayenite compound powder having a conduction electron density of 10 15 cm −3 or more and a specific surface area of 5 m 2 g −1 or more is produced by: the following steps: (1) forming a precursor powder by subjecting a mixture of a starting material powder and water to a hydrothermal treatment; (2) forming a mayenite compound powder by heating and dehydrating the precursor powder; (3) forming an activated mayenite compound powder by heating the compound powder in an inert gas atmosphere or in a vacuum; and (4) injecting electrons into the mayenite compound through a reduction treatment by mixing the activated mayenite compound powder with a reducing agent.

First claim

The invention claimed is:

1. A mayenite compound having a conduction electron concentration of 10 15 cm −3 or more and a specific surface area of 5 m 2 g −1 or more.

2. The mayenite compound according to claim 1 , wherein the mayenite compound is used as a support of a transition metal catalyst.

3. The mayenite compound according to claim 1 , wherein the mayenite compound is in powder form.

4. The mayenite compound according to claim 1 , wherein the mayenite compound is in a cage skeleton form.

5. The mayenite compound according to claim 1 , wherein the mayenite compound is activated.

6. A supported metal catalyst comprising:
a support comprising a conductive mayenite compound of claim 1 ; and
a transition metal catalyst supported on the conductive mayenite compound support.

7. A method of synthesizing ammonia, the method comprising:
providing a transition metal catalyst supported on the mayenite compound according to claim 1 ;
supplying nitrogen gas (N 2 ) and hydrogen gas (H 2 ) to contact with the transition metal catalyst so as to react with each other to produce ammonia gas (NH 3 ).

8. The mayenite compound according to claim 1 , wherein the mayenite compound is a conductive mayenite compound.

9. The mayenite compound according to claim 1 , wherein the mayenite compound has a specific surface area of 6 m 2 g −1 or more.

10. The mayenite compound according to claim 1 , wherein the mayenite compound has a specific surface area of 10 m 2 g −1 or more.

Assignees

• Tokyo Inst Tech
• Japan Science & Tech Agency

Inventors

• Hosono Hideo
• Hara Michikazu
• Inoue Yasunori
• Kitano Masaaki
• Hayashi Fumitaka
• Yokoyama Toshiharu
• Matsuishi Satoru
• Toda Yoshitake

Classifications

• B01J37/10

  in the presence of water, e.g. steam · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title

• B01J37/082

  Decomposition and pyrolysis · CPC title

• B01J23/02

  of the alkali- or alkaline earth metals or beryllium · CPC title

• B01J37/04

  Mixing {(B01J37/0009, B01J37/0018 take precedence)} · CPC title