Investigation of the energetics of the reactions of NH2 species with hydrogen and NO on the Pt(100) surface by the method of UBI-QEP

The formation of NH2,ads and its further reactions with hydrogen and NO on the Pt(100) surface were previously studied by the methods of HREELS and TPR, in order to understand the role of amino species in the mechanism of the NO+H-2 reaction. In this work the method of unity bond index-quadratic exponential potential (UBI-QEP) has been employed to rationalize the experimental findings by calculating the energies associated with the envisaged routes of reactions. It is concluded that the activation energy of formation of NH2,ads is higher than water production. The simplicity of recombinative desorption of N-2 is due to the decrease of its activation energy because of the destabilizing effect of O-ads and NOads. The rate-determining step of explosive surface reaction in the saturated coadsorption layer of NH2,ads and NOads is dissociation of NOads. Autocatalytic acceleration of the explosive reactions is due to the decrease of activation energy of the rds by increasing the number adsorption vacant sites. H2O is produced via two different processes with different activation energies. NH3 is produced via several paths.