Estudio computacional del efecto de H2 en la disociación de nitratos en superficies metálicas y bimetálicas de Pd, Rh y Cu

Abstract

Abstract: The present work focused on the study of the decomposition of nitrates, which has been applied for some years as an alternative to purify water; In particular, the molecular dissociation of sodium nitrate and the effect of H2 on the formation of N2 are studied through the DFT method. For this, models of monometallic surfaces (100), (110) and (111) of Pd and Rh were used; and, bimetallic of Cu/Pd and Cu/Rh. The sites studied for the nitrate molecule were top, bridge, 3- fold and 4-fold, of which the most active in breaking N-O bonds were top and bridge sites, on surfaces (100) and (111) of mono and bimetallic. The dissociation of the N-O bonds on the bimetallic surfaces occurs at the monometallic sites of the bimetallic slab. These results indicate that H2 facilitates the breaking of the N-O bond of the nitrate molecule in the catalytic reduction towards N2. Furthermore, H2 acts on the noble metal (Pd or Rh) as a reductant agent, regenerating the metal surface during the reaction.