Ethanol Dehydrogenation on Pt/Cu(111) Surfaces

Reflection absorption infrared spectroscopy (RAIRS) was used to directly identify an ethoxy intermediate formed by the dry dehydrogenation of ethanol on a Pt/Cu(111) single-atom alloy surface. Temperature-programmed reaction spectroscopy was used to monitor reaction-limited desorption of acetaldehyde that follows from activation of a C–H bond of ethoxy. The RAIRS results for ethoxy formed on the Pt/Cu(111) surface were compared to RAIR spectra of ethoxy at a coverage of 0.5 monolayer formed on oxidized Cu(111). Quantification of the ethoxy coverage from the RAIRS intensities indicated that it was less than the Pt coverage on the Pt/Cu(111) surface. This is contrary to the expectation that one Pt site could form multiple ethoxy molecules on Cu sites through spillover. Possible reasons for not detecting ethoxy spillover in these experiments are discussed.