The adsorption behaviour of isobutane on Pt(533): A combined RAIRS and TPDstudy

The adsorption of isobutane on a Pt(533) stepped surface has been investiga ted using temperature programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS). Isobutane exists in two monolayer states an d one multilayer phase on the Pt(533) surface. The most stable desorption s tate is caused by isobutane desorbing from the terrace planes. The orientat ion of isobutane in this state was determined from RAIRS measurements. The second monolayer phase probably belongs to isobutane molecules with only tw o hydrogen atoms in direct contact with the surface. RAIRS spectra also sho wed there was little bond weakening due to metal adsorbate interaction. (C) 2000 Elsevier Science B.V. All rights reserved.