The surface chemistry of ethyl iodide on hydrogen-covered Ni(100) surfaces

• Published in: Surface science Vol. 322; no. 1; pp. 140 - 150
• Main Authors: Tjandra, Sariwan, Zaera, Francisco
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1995; Amsterdam Elsevier Science; New York, NY
• Subjects: Catalysis; Chemisorption; Chemistry; Exact sciences and technology; General and physical chemistry; Isotopic exchange/traces; Solid-gas interface; Surface and interface chemistry; Surface chemical reaction; Surface physical chemistry; Thermal desorption; Thermal desorption spectroscopy; Isotopic exchange/traces; Chemisorption; Surface chemical reaction; Thermal desorption; Catalysis; Thermal desorption spectroscopy; Gas solid adsorption; Surface reaction; Hydrogen; Coadsorption; Gas solid interface; Thermodesorption; Nickel; Experimental study
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(95)90025-X

The reactivity of ethyl iodides on hydrogen predosed Ni ( 100) surfaces has been studied by using temperature programmed desorption (TPD) spectroscopy. The data show that hydrogen coadsorption inhibits the decomposition of ethyl groups at all coverages. Also, at ethyl iodide coverages below saturation, the yields of both ethylene and ethane (the products of β-hydride and reductive elimination reactions respectively) increase equally with hydrogen coadsorption, but near saturation the desorption of ethane increases at the expense of ethylene production. A small amount of ethane is also produced via the hydrogenation of chemisorbed ethylene. This latter reaction occurs at higher temperature, which means that its activation energy is higher than that for the direct hydrogenation of the ethyl species. No coupling or H-D exchange reactions were observed in our experiments.