Alumina-based composite oxide and production method for same

Patent metadata

Field	Value
Publication number	US-12077449-B2
Application number	US-202117497688-A
Country	US
Kind code	B2
Filing date	Oct 8, 2021
Priority date	Jun 30, 2017
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

Provided is an alumina-based composite oxide having a large initial specific surface area and a small initial mean pore size, with excellent heat resistance of the specific surface area and pore volume; and a production method therefor. Specifically, provided is an alumina-based composite oxide wherein the initial crystallite diameter is 10 nm or less and the initial specific surface area is 80 m 2 /ml or more; after calcination at 1200° C. for 3 hours in air, the specific surface area is 10 m 2 /ml or more; the initial mean pore size is 10 nm or more and 50 nm or less; and after calcination at 1200° C. for 3 hours in air, the pore volume retention rate is 10% or more, which is determined by (P 1 /P 0 )×100 wherein P 0 represents an initial pore volume (ml/g), and P 1 represents a pore volume (ml/g) after calcination at 1200° C. for 3 hours in air.

First claim

The invention claimed is:

1. A method for producing an alumina-based composite oxide, the method comprising:
step 1 of obtaining an aqueous solution A consisting of a raw material salt containing two or more metals including an aluminum, and water,
step 2 of obtaining an aqueous solution B of a soluble carbonate and/or a soluble hydrogen carbonate,
step 3 of mixing the aqueous solution A and the aqueous solution B to obtain precipitates of an aluminum-based composite hydroxide, and
step 4 of subjecting the precipitates to heat treatment at 400 to 900° C. to obtain the alumina-based composite oxide,
wherein the alumina-based composite oxide has an initial crystallite diameter of 10 nm or less and an initial specific surface area of 80 m 2 /ml or more;
wherein the alumina-based composite oxide after calcination at 1200° C. for 3 hours in air has a specific surface area of 10 m 2 /ml or more;
wherein the alumina-based composite oxide has an initial mean pore size of 10 nm or more and 50 nm or less; and
wherein the alumina-based composite oxide after calcination at 1200° C. for 3 hours in air has a pore volume retention rate of 10% or more, the retention rate being represented by (P 1 /P 0 )×100 wherein P 0 represents an initial pore volume in ml/g, and P 1 represents a pore volume in ml/g after calcination at 1200° C. for 3 hours in air.

2. The method according to claim 1 , wherein the aqueous solution B is an ammonium bicarbonate aqueous solution.

Assignees

• Daiichi Kigenso Kagaku Kogyo

Inventors

• Hayashida Hiroyuki
• Hirose Yoshikazu

Classifications

• C01P2006/16

  Pore diameter · CPC title

• C01P2006/14

  Pore volume · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2006/17

  Pore diameter distribution · CPC title

• C01F7/308

  Thermal decomposition of nitrates · CPC title