TPD and HREELS study of the reaction of guaiacol on Zn-decorated Pt(111)

Temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS) were used to characterize the adsorption and reaction of guaiacol on Pt(111) and Zn-modified Pt(111) surfaces. It was found that the guaiacol molecule binds to the Pt(111) surface via the aromatic ring which facilitates unselective decomposition to produce CO, H-2 and small hydrocarbon fragments at relatively low temperatures. In contrast, on Zn-modified Pt(111) surfaces, guaiacol was found to bond to surface Zn sites via the oxygen atoms in the molecule producing a bonding configuration in which the aromatic ring is tilted away from the surface. Such a binding configuration facilitates the desired C-O bond cleavage while keeping the aromatic nature of the molecule intact.