摘要 |
Provided is a process for producing satisfactory particles held in porous silica. The process comprises (a) the step of preparing porous silica, (b) the step of bringing the porous silica into contact with a liquid which contains either a metal or a compound that has the metal as a component element and infiltrating the liquid into the pores of the porous silica, and (c) the step of subjecting, after the step (b), the impregnated porous silica to a heat treatment to thereby form fine particles comprising the metal or the metal compound in the pores of the porous silica. When porous silica is synthesized by hydrolyzing an alkoxysilane in a solvent-free system, it is possible to synthesize porous silica having a fine pore diameter. Use of this porous silica as a template facilitates formation of particles (e.g., W, Cu, Cr, Mn, Fe, Co, or Ni or an oxide of any of these metals) that show peculiar properties not observed in the bulk material. |