Decomposition of PF3 on Ni(755) and coadsorption with ethylcyclohexane: Comparing the results of PF3 with CO

Temperature-programmed desorption spectra for exposure of PF3 on Ni(755) ar e characterized by two desorption features around 350 and 650 K. The lower temperature feature is assigned to the molecular desorption and the higher one to the recombinative desorption of PF3 fragments, respectively. The res ults suggest that the decomposition of PF3 occurs at the step sites but not on the terrace of Ni(755). Coadsorbed PF3 inhibits the decomposition of et hylcyclohexane almost completely and the inhibiting effect of PF3 is more e ffective than that of CO. We can obtain the same decomposition starting tem perature (the temperature where an adsorbed hydrocarbon starts to decompose ) of ethylcyclohexane by using the inhibiting effects of PF3 and CO. (C) 20 01 Academic Press.