Patent ID: 7968490

Claim:
A method for producing a porous substance, the method comprising: (a) holding a phase comprising secondary particles of the porous substance in micelles or inverse micelles in a dispersed state in a solvent with a surfactant; (b) agglomerating the secondary particles held in the micelles or inverse micelles by adjusting pH of microemulsion at room temperature from 7 to 9, and thereafter performing a treatment to resolve the dispersed state of the micelles or inverse micelles containing the secondary particles; and (c) baking the agglomerated secondary particles; wherein: the treatment to resolve the dispersed state comprises adding a small polar molecule that is soluble in both an organic solvent and water and that reduces the surface activation of the surfactant, the small polar molecule is at least one member selected from the group consisting of alcohols having 1 to 3 carbon atoms, glycols having 1 to 3 carbon atoms, and aldehydes having 1 to 3 carbon atoms; and the secondary particles held in the micelles or inverse micelles are agglomerated to form mesopores having a diameter of 5 to 30 nm between the secondary particles, the secondary particles are composite oxide particles in which metallic ions are incorporated, and the secondary particles include cerium-zirconium composite oxide or lanthanum-zirconium composite oxide.