Efficient N2 formation on Ag(111) by eley-rideal recombination of hyperthermal atoms

Using molecular dynamics simulations and potential energy surfaces of ab initio quality, we show that direct pickup of N adsorbates by gas-phase N is a highly efficient channel for N2 formation on Ag(111). This recombination process, called Eley-Rideal, was traditionally associated with lighter projectiles and regarded as marginal, but here, we obtain reactivities for N of ≳35% even at incident energies of a few eV. The good agreement found between simulated and published experimental energies of the desorbed N2 is a fingerprint of this otherwise elusive recombination. © 2013 American Chemical Society.
Work supported in part by the Basque Departamento de Educación, Universidades e Investigación, the University of the Basque Country UPV/EHU (Grant No. IT-366-07) and the Spanish Ministerio de Ciencia e Innovación (Grant No. FIS2010-19609-C02-02). M.B.-R. acknowledges the Gipuzkoako Foru Aldundia and the European Commission (Grant No. FP7-PEOPLE-2010-RG276921). G.A.B. acknowledges ANPCYT (Grant No. PICT 2010-1558).