| Isocyanate, NCO, is known to form on platinum-group metals in the course of the catalytic reduction of NO by carbon-containing molecules, such as CO or simple hydrocarbons. The surface chemistry of isocyanate and its precursor, isocyanic acid, HNCO, have been presented in this thesis. This study was done under ultrahigh vacuum (UHV) conditions on Pt(111) with surface sensitive techniques.;Exposure of the Pt(111) surface at 90 K to HNCO leads to both molecularly adsorbed HNCO, as well as its dissociation products, H and NCO. The decomposition of HNCO is largely completed when the surface is heated to 150 K. As the temperature is increased from 150 to 300 K, a series of HNCO and NCO decomposition products are identified with RAIRS, including CO, NH, NH2, NH3, H2O, OH, and NO. These reaction products indicate that NCO dissociation can occur at both the N-C and C-O bonds.;It has also been shown that the co-adsorption of oxygen and nitrogen atoms stabilize the HNCO species beyond 300 K, as compared with the disappearance of RAIRS peaks associated with HNCO on Pt(111) (∼ 150-200 K) alone. Molecular oxygen co-adsorption stabilizes the NCO species beyond 300 K as well.;Finally, the formation of NCO on the Pt(111) surface has been attempted using a variety of adsorbates. Isocyanate was successfully produced from the reaction of acetylene-derived carbon with NO, albeit in small quantities. |
