Method for producing porous body

Abstract

The present invention addresses the problem of providing a method for producing, without a reflux heating treatment, a porous body having a co-continuous structure formed from macropores and a ceramic framework including micropores. In order to solve the problem, the present invention provides a method for producing a porous body having a co-continuous structure formed from macropores (2) and a ceramic framework (1) including micropores (3). The method comprises: (a) a step for impregnating, with an alkali solution, a starting gel having a co-continuous structure formed from a framework phase and a solvent phase to obtain an impregnation-treated gel; (b) a step for heating the impregnation-treated gel in gas; and (c) a step for firing the heated impregnation-treated gel at a temperature higher than the heating temperature in step (b) to obtain the porous body. The solid fraction of the starting gel is at most 40.0 mass%.

Claims

1. A method for producing a porous body having a co-continuous structure formed by a ceramic skeleton containing micropores and coarse pores, comprising the following steps: (a) impregnating a starting gel having a co-continuous structure formed by a skeletal phase and a solvent phase with an alkaline solution to obtain an impregnated gel; (b) heating the impregnated gel in a gas; (c) firing the impregnated gel after heating at a temperature higher than the heating temperature in step (b) to obtain the porous body, wherein the solid content of the starting gel is 40.0% by mass or less.

2. The manufacturing method according to claim 1, wherein the ratio of the specific surface area of ​​the porous body to the specific surface area of ​​the dried starting gel is 10 or more and 1000 or less.

3. The manufacturing method according to claim 1 or 2, wherein in the impregnation-treated gel obtained in step (a), the ratio of the mass of the alkaline solution contained in the impregnation-treated gel to the dry mass of the impregnation-treated gel is 0.01 or more and 5.00 or less.

4. The manufacturing method according to claim 1 or 2, wherein in step (b), the impregnation treatment gel is heated in the gas to a temperature of 50°C or higher and 250°C or lower.

5. The manufacturing method according to claim 1 or 2, wherein the alkaline solution contains one or more alkalis selected from alkali metal hydroxides and alkaline earth metal hydroxides.

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