The molecular orientation of NO and N 2O during adsorption on Ir(111) is observed by combining the wavelength-dispersive x-ray absorption spectroscopy with 1 Hz switching between the vertical and horizontal linear polarizations. It is revealed that NO adsorbs keeping its molecular axis at ∼ 20 ° from surface normal. In contrast, N 2O rapidly adsorbs up to 2/3 of the saturation coverage with an orientation angle of ∼ 35°, then turns to a slow adsorption phase with larger orientation angles, and gradually reaches its saturation with an average orientation angle of ∼ 45 °. Such a complicated behavior is interpreted by assuming different adsorption sites.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)