The structure and reactivity of 2-butanol on Pd(1 1 1)

The structure, formation and decomposition pathways of 2-butoxide species formed on a Pd(1 1 1) surface following the adsorption of 2-butanol is studied by a combination of density functional theory (DFT), analysis of the low-energy electron intensity versus beam energy curves (LEED I/E) and temperature-programmed desorption (TPD). Both DFT calculations and LEED I/E measurements reveal that 2-butoxide adsorbs with the oxygen atom located in the three-fold hollow sites on Pd(1 1 1) with the C-O bond almost perpendicular to the surface with the 2-butyl group in the trans configuration. At coverages below ∼0.11 monolayers, adsorbed 2-butoxide species completely thermally decompose to desorb hydrogen and carbon monoxide. The 2-butoxide species present at higher coverages either hydrogenate to reform 2-butanol or undergo a β-hydride elimination reaction to form 2-butanone.