Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Ethylene Oxidation Mechanisms and Intermediates: In Situ Soft X-Ray Studies of Ethylene Oxidation on the Pt(111) Surface

Published

Author(s)

D J. Burnett, A M. Gabelnick, J L. Gland, Daniel A. Fischer

Abstract

In situ studies of ethylene oxidation on Pt(111) have been performed using a powerful combination of fluorescence yield soft x-ray methods for temperatures up to 600 K and oxygen pressures up to 1.3 Pa. Absolute carbon coverages have been determined both in steady state and dynamic catalytic conditions on the Pt(111) surface. Fluorescence yield near-edge spectroscopy (FYNES) and temperature-programmed fluorescence yield near-edge spectroscopy (TP-FYNES) experiments above the carbon K edge were used to identify the structure and bonding of the dominant surface species during oxidation. TP-FYNES experiments of preadsorbed ethylene monolayers in oxygen pressures up to 1.3 Pa indicate a stable intermediate is formed over the 300 K to 340 K temperature range. By comparing the C-H s* resonance at the magic angle with the intensity in the carbon continuum, the stoichiometry of this intermediate can be determined explicitly. Based on calibration with known C:H stoichiometries, the intermediate has a C2H3 stoichiometry for oxygen pressures up to 1.3 Pa, indicating oxydehydrogenation occurs before skeletal oxidation. FYNES spectra at normal and glancing intermediates were performed to characterize the structure and bonding of this intermediate, using FYNES spectra of ethylene, ethylidyne, and acetylene as reference standards. This procedure indicates the oxidation intermediate is tri-s vinyl. Thus, oxidation of ethylene proceeds through a vinyl intermediate with oxydehydrogenation preceding skeletal oxidation.
Citation
Journal of Physical Chemistry B
Volume
109

Keywords

ethylene, intermediates, oxidation, platinum, soft x-ray, surface science

Citation

Burnett, D. , Gabelnick, A. , Gland, J. and Fischer, D. (2005), Ethylene Oxidation Mechanisms and Intermediates: In Situ Soft X-Ray Studies of Ethylene Oxidation on the Pt(111) Surface, Journal of Physical Chemistry B (Accessed May 27, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created March 9, 2005, Updated October 12, 2021