Adsorption of methanol on Ni3Al(1 1 1) and NiAl(1 1 0): A high resolution PES study

The adsorption of methanol on Ni3Al(1 1 1) and NiAl(1 1 0) has been studied using high resolution photoemission spectroscopy (HR-PES) and density functional theory (DFT). Both methanol and methoxy are formed on these surfaces after the initial methanol exposure at low temperatures. Heating to 200 K leads to further formation of methoxy. On NiAl(1 1 0) two different methoxy species are observed where the first is formed upon methanol adsorption, and the other results from methanol decomposition during heating. The DFT calculations show that methanol and methoxy interacts with the Al atoms on both surfaces. Methanol is found to bond through the oxygen atom to the Al on-top site on Ni3Al(1 1 1) and NiAl(1 1 0) with the C-O axis tilted with respect to the surface normal. On Ni3Al(1 1 1) methoxy is situated in a 2Ni+Al hollow site, whereas on NiAl(1 1 0) the Al-Al bridge site is preferred.