US 12,440,825 B2
Method for synthesizing SiO2Al2O3 containing sol solution and method for forming porous alumina film
Akira Hasegawa, Aomori (JP); Osamu Okada, Kyoto (JP); Hiromi Nakamura, Kyoto (JP); and Shizuka Ogasawara, Kyoto (JP)
Assigned to Renaissance Energy Research Corporation, Kyoto (JP); and National Institute Of Technology, Tokyo (JP)
Filed by Renaissance Energy Research Corporation, Kyoto (JP); and NATIONAL INSTITUTE OF TECHNOLOGY, Tokyo (JP)
Filed on May 28, 2025, as Appl. No. 19/221,361.
Application 19/221,361 is a division of application No. 18/835,990, granted, now 12,343,703, previously published as PCT/JP2023/010790, filed on Mar. 20, 2023.
Claims priority of application No. 2022-050413 (JP), filed on Mar. 25, 2022.
Prior Publication US 2025/0288974 A1, Sep. 18, 2025
Int. Cl. B01J 21/12 (2006.01); B01J 23/02 (2006.01); B01J 37/00 (2006.01); B01J 37/02 (2006.01); B01J 37/03 (2006.01); B01J 37/06 (2006.01); B01J 37/08 (2006.01)
CPC B01J 21/12 (2013.01) [B01J 23/02 (2013.01); B01J 37/009 (2013.01); B01J 37/0215 (2013.01); B01J 37/0236 (2013.01); B01J 37/031 (2013.01); B01J 37/06 (2013.01); B01J 37/08 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for synthesizing SiO2Al2O3 containing sol solution for forming a porous alumina to which silica is added, the method including:
preparing an alkoxysilane solution comprising an alkoxysilane, water, an alcohol, and an inorganic acid;
preparing an aluminum solution comprising an aluminum compound and water, the aluminum compound being selected from among aluminum nitrate, sodium aluminate, aluminum chloride, and aluminum sulfate;
precipitating a precipitate of aluminum hydroxide in the aluminum solution;
filtering the precipitate from the aluminum solution, and washing the filtered precipitate with water to prepare a precipitate cake;
preparing Al2O3 containing sol solution, in which boehmite particles are dispersively present as sol particles, by preparing a slurry solution with adding water to the precipitate cake, performing a pH adjusting treatment on the slurry solution, and thereafter performing an autoclave treatment on the slurry solution; and
preparing the SiO2Al2O3 containing sol solution, in which sol particles with silica bonded to boehmite particles are dispersively present, by adding the alkoxysilane solution to the Al2O3 containing sol solution,
wherein the pH adjusting treatment on the slurry solution controls pH value of the slurry solution within a specific pH range so that a solution state of the Al2O3 containing sol solution after the autoclave treatment is a sol state.