ELECTROLYSIS ELECTRODE, POSITIVE ELECTRODE FOR PRODUCING OZONE ELECTROLYSIS, POSITIVE ELECTRODE FOR PRODUCING PERSULFATE ELECTROLYSIS, AND POSITIVE ELECTRODE FOR CHROMIUM ELECTROLYTIC OXIDATION

摘要

The purpose of the present invention is to provide an electrolysis electrode used in electrolytic oxidation reactions, the electrode having a high oxygen overvoltage and extended service life. The electrolysis electrode has an electrode surface layer formed from a valve metal oxide film by a high-temperature heat treatment at a low oxygen partial pressure of 100 Pa or less; the layer directly underneath the electrode surface layer comprising a valve metal and a noble metal other than silver (Ag); and the noble metal being precipitated and dispersed in the crystal grain boundaries of the valve metal; wherein the crystals of the valve metal to a depth within 30 µm in a perpendicular direction from the electrode surface are elongated crystal grains in a cross section cut perpendicularly to the electrode surface; and the content of the noble metal to a depth within 10 µm in the perpendicular direction from the electrode surface is 5 at.% or less.