Direct verification of a high-translational-energy molecular precursor to oxygen dissociation on Pd(111)

• Published in: Surface science Vol. 419; no. 1; pp. L107 - L113
• Main Authors: Nolan, P.D, Lutz, B.R, Tanaka, P.L, Mullins, C.B
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 24-12-1998; Amsterdam Elsevier Science; New York, NY
• Subjects: Chemistry; Direct molecular chemisorption; Exact sciences and technology; General and physical chemistry; Oxygen; Pd surface; Solid-gas interface; Surface physical chemistry; Direct molecular chemisorption; Oxygen; Pd surface; Inorganic adsorbate; Gas solid adsorption; Chemisorption; EEL spectroscopy; Gas solid interface; Metallic adsorbent; Transition metal; Palladium; Dissociation; Experimental study
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00759-6

Adsorption of high-translational-energy oxygen on Pd(111) was examined with electron energy-loss spectroscopy (EELS) and molecular beam techniques. EEL spectra indicate that a direct
molecular chemisorption mechanism holds at high kinetic energies (up to 1.27
eV) on a 77
K substrate. The initially intact peroxo-like species proceeds to dissociation or desorption only after sufficient heating – direct dissociation from the gas phase appears to be negligible. We estimate the thermal activation barrier for conversion from the peroxo-like species to be approximately 0.32
eV. Initial adsorption probability measurements in this high-kinetic-energy regime support a molecular chemisorption-initiated mechanism.