Method for manufacturing noble metal fine particles

Abstract

A method for manufacturing noble metal fine particles, by which noble metal fine particles are obtained whose particle diameter and alloy composition are easy to control and whose crystallinity and purity are high, is provided. The method includes the steps of: (1) obtaining a molten mixture containing a noble metal chloride, by insufflating chlorine gas into a mixture of a molten salt of an alkali metal chloride and a noble metal; (2) obtaining a noble metal oxide as a precipitate by adding an alkali metal carbonate to the molten mixture under an inert gas atmosphere; (3) obtaining a mixture containing noble metal oxide fine particles, by pulverizing the noble metal oxide with at least one of an alkali metal carbonate and an alkali earth metal carbonate; and (4) obtaining noble metal fine particles by heating the mixture obtained in step (3) under an atmosphere of gas containing hydrogen, and then treating the heat-treated mixture with acid.

Dependencies are inferred from the claim text.