A TEMPERATURE-PROGRAMMED X-RAY PHOTOELECTRON SPECTROSCOPY STUDY OF THE DECOMPOSITION REACTIONS OF UNSATURATED HYDROCARBONS ON Ni(100)

Abstract

We present a temperature-programmed X-ray photoelectron spectroscopy study of the thermal chemistry of acetylene, ethylene and propene on Ni(100) using synchrotron radiation. The use of a third generation light source makes it possible to measure high resolution photoemission spectra within a few seconds approaching the ideal of real-time analysis. The evolution of the C 1s core level spectra has been monitored in situ as a function of sample temperature from 90 to 530 K. Analysis of binding energies and changes in intensities and correlation with previous data from the literature have allowed us to distinguish the surface intermediates formed during the thermal reactions. The resultant temperature-dependent intensity curves clarify the dehydrogenation mechanisms of acetylene and ethylene and provide new insight into the decomposition of propene.