The effect of noble metal treatment on the 304 stainless steel (SS) oxide formed in high temperature water containing excess hydrogen was examined by the transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The electrochemical corrosion
potential (ECP) of noble metal treated 304 SS electrode was also measured to confirm the presence of noble metal on the oxide surface. It was observed that under excess hydrogen water chemistry condition, the presence of Pt and Rh on the oxide surface promotes the transformation of alpha-Fe2O3 to a spinel Fe304 type, a Zn-enriched outer oxide particle and a Cr-enriched inner oxide layer and, thereby, increases the iron concentration in water. Keywords: noble metal, 304 SS ECP, high temperature water, oxide, TEM