Reaction Pathways of Propanal and 1-Propanol on Fe/Ni(111) and Cu/Ni(111) Bimetallic Surfaces

The adsorption and reaction of propanal and 1-propanol were compared on Ni(111), Fe/Ni(111), and Cu/Ni(111) surfaces by using density functional theory (DFT), temperature-programmed desorption (TPD), and high-resolution electron energy loss spectroscopy (HREELS) as probe reactions for reforming of oxygenates for hydrogen production. DFT calculations predict that the binding energy trend of propanal and 1-propanol is Fe/Ni(111) > Ni(111) > Cu/Ni(111). For propanal the Ni(111) surface shows the highest reforming and total activity, the Fe/Ni(111) surface shows the highest decarbonylation activity to produce gas-phase ethylene, and the Cu/Ni(111) surface shows the highest total decomposition activity, attributed to the adsorption of propanal through the O lone pair. For 1-propanol the Ni(111) surface shows the highest reforming and total activity and produces propanal via a selective dehydrogenation pathway while both Fe/Ni(111) and Cu/Ni(111) surfaces favor the decomposition pathway to produce CO and surface hydrocarbons.