Self-consistent periodic DFT-GGA calculations are used to investigate the NO reduction reaction in the presence of atomic H on 6 close-packed transition metal surfaces namely, Cu(111), Ag(111), Ru(0001), Rh(111), Pd(111), Ir(111), and Pt(111). The chemisorption of molecular HNO and NOH (reaction intermediates) species and co- adsorption of NO, NH, N, NH, OH an O (initial and end products of reactions) on each metal surface has been systematically studied and the preferred binding sites and binding energies are determined for a 1/4 ML surface coverage. Based on these results the thermodynamic potential energy surfaces (PESs) are developed for H-assisted NO reduction reaction on all the surfaces studied. These PESs suggest that for some metal surfaces H-assisted NO reduction is quite favorable whereas for other metals it hardly has any effect.