Anhydrous Ethanol Dehydrogenation on Metal–Organic Chemical Vapor Deposition Grown GaN(0001)

Abstract

In this ultrahigh vacuum study, temperature-programmed desorption, Auger electron spectroscopy, and ex-situ atomic force microscopy are used to evaluate the surface chemistry of ethanol on the GaN(0001) surface. Ethanol undergoes dehydration and dehydrogenation reactions on the GaN(0001) surface to a larger extend than on the TiO2(110) surface. This enhanced reactivity is attributed to a higher amount of metal-bound ethoxy. In addition, molecular H2 has been identified as a byproduct of the ethanol dehydrogenation to acetaldehyde. We attribute the reactivity, including the formation of molecular hydrogen, to the combination of wurtzite structure and nitride chemistry, since surface amines are considered to be less stable than surface hydroxyls on other model oxides.