ETHANOL DECOMPOSITION ON NI(111) - OBSERVATION OF ETHOXY FORMATION BY IRAS AND OTHER METHODS

The first step in the decomposition of chemisorbed ethanol on Ni(111) has been investigated using IRAS, XPS and TPD methods. Ethanol decomposes via a first step in which O-H bond scission occurs. This reaction starts from a chemisorbed ethanol structure which is bonded to the surface through both O and H moieties with the O-H bond almost parallel to the surface. This leads to a strong deuterium kinetic isotope effect for both the ethanol decomposition step and the competitive ethanol desorption step. IRAS studies indicate that the average orientation of the (C3v) axis of CH3 becomes more parallel to the Ni(111) surface when chemisorbed ethanol converts to adsorbed ethoxy. Chemisorbed ethoxy possesses a structure where the C-O bond is tilted away from the surface normal, as judged by the observation of nu-as(CH2) intensity by IRAS.