Adsorption and Dehydrogenation of Decaborane on the Pt(111) Surface

Abstract

The adsorption and decomposition of decaborane (B10H14) on the Pt(111) surface was studied with reflection absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). The molecule has a nido structure with 10 terminal B−H bonds and 4 bridging B−H−B bonds. Comparison of the experimental RAIR spectra with spectra calculated using density functional theory indicates that the molecule adsorbs at 85 K without dissociation and with an orientation in which the dipole moment is parallel to the surface. The TPD experiments show that the dissociation leads to H2 desorption up to ∼420 K but that no boron-containing species desorb. Dissociation occurs in stages via stable surface intermediates, as indicated by changes observed with RAIRS in the terminal B−H stretch region at ∼2600 cm−1. Boron, which is produced as a result of complete dissociation, is lost from the surface as indicated by XPS, most likely through dissolution into the bulk of the platinum crystal.