Method for producing a particle containing porous silica, porous silica, and a particle containing porous silica

A method for producing a particle containing porous silica comprising the following steps:

• (a) producing porous silica by hydrolysis of alkoxy silane comprising the following steps:
• (a1) mixing a surfactant and an alkoxy silane to form a mixed solution;
• (a2) hydrolyzing the alkoxy silane by adding water to the mixed solution;
• and
• (a3) removing the surfactant by heat treatment after the (a2) process;
• (b) synthesizing the particle in the pores of porous silica produced in the step (a), and,
• (c) removing the porous silica and obtaining a metallic oxide after the step (b),
• wherein the step (b) is contacting the porous silica with solution or gas containing a compound comprising the metal of the metallic oxide as a component element to introduce pores of the porous silica with the solution or gas, and forming the particle containing the metallic oxide in the pores of the porous silica by heat treatment,
• wherein the surfactant is a cationic surfactant of which carbon atoms of a hydrophobic group is 2 to 7,
• wherein in the step (a2), silica is formed by the hydrolysis with micelle of the surfactant used as a template under a condition of a stoichiometric ratio of alkoxy silane:water=1:n, the amount of water is an amount in which n is 2 to 4;
• and, pH value of the water is 0 to 2, and
• an average pore diameter of the porous silica is 0.5 nm or more to 1.5 nm or less.