A search for precursor states to molecular nitrogen chemisorption on Ni(100), Re(0001) and W(100) surfaces at ∼ 20 K

• Published in: Surface science Vol. 139; no. 1; pp. 109 - 120
• Main Authors: Grunze, M.J., Fühler, J., Neumann, M., Brundle, C.R., Auerbach, D.J., Behm, J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.04.1984; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Chemistry; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; General and physical chemistry; Materials science; Metals, semimetals and alloys; Metals. Metallurgy; Physics; Solid-gas interface; Specific materials; Surface physical chemistry; Inorganic adsorbate; Reaction intermediate; Chemisorption; Crystal face; Transition metal; X ray; Nitrogen; Experimental study; Gas solid adsorption; Adsorption; Gas solid interface; Metallic adsorbent; Photoelectron spectrometry; Low temperature
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(84)90012-8

We have studied adsorption and condensation of molecular nitrogen on Ni(100), Re(0001) and W(100) surfaces by XPS at surface temperatures ⩾ 20 K in order to search for a precursor state to the linearly bonded chemisorbed state (γ-state). Our data however show XPS spectra only from γ-N 2 at low exposures and from physisorbed and condensed N 2 at higher exposures. No intrinsic precursor is found, allowing an upper bound of approximately 3 kJ/mol to be placed on the activation barrier between any such state and the chemisorbed state. The physisorbed N 2 observed on top of γ-N 2 covered patches acts as an extrinsic precursor to chemisorption.