Oxidation of NiAl(210) surface at room temperature using supersonic oxygen molecular beam; Real-time photoemission spectroscopic study with synchrotron radiation

Syu, Y.*; 櫻井 惇也*; 寺岡 有殿; 吉越 章隆; 出村 雅彦*; 平野 敏幸*

no journal, , 

Intermetallic compounds (IMCs) usually have ordered crystal structure which differs from that of their constitute metals. Some of them have been reported to show good catalytic properties for some reactions, such as PtTi, NiSn, and NiAl, demonstrating that IMCs have potential as catalysts and/or catalyst precursors for chemical reactions. In this work, we investigate the initial oxidation process on a NiAl(210) surface at 298 K using a supersonic oxygen molecular beam and a real-time photoemission spectroscopy with synchrotron radiation. The time evolutions of O 1s, Ni 2p, Al 2p, and Ni 3p spectra indicate that both Al and Ni are oxidized, and AlO and NiO are formed during the irradiation of oxygen molecules. The oxidation rate of Al is much higher than that of Ni at the beginning of oxidation, and then quickly saturates. In contrast, the oxidation of Ni progresses gradually for the whole measured period.