First principles calculations had been performed to present the effects of barium atom on dissociation of nitrogen molecule on Ru(0001) surface. Barium atoms became cations on Ru(0001) surface by lose electrons. Charge transfer enhanced the hybridization between d orbitals of substrate and π orbitals of nitrogen molecule. Bond strength of nitrogen molecule was weakened by effects of barium atom. Bond length of γ state nitrogen molecule was increased from 0.113 nm on Ru(0001) surface to 0.123 nm on Ru(0001)-Ba surface, and stretch vibration frequency was decreased from 2221 to 1745 cm^－1. Bond length of α state nitrogen molecule was increased from 0.120 nm on Ru(0001) surface to 0.133 nm on Ru(0001)-Ba surface, and vibration frequency was decreased from 1486 to 1052 cm^－1. The barrier energy of nitrogen molecular dissociation on Ru(0001) surface was reduced from 2.06 to 1.17 eV by effects of barium atom, and activities of Ru(0001) terrace surface was magnified about 9 orders at 500 K. It was indicated that barium atom had some characters to be an electronic promoter on the process of activating nitrogen molecules on Ru(0001) surface.

Key words: nitrogen dissociation, Ru(0001), adsorption energy, molecular vibration, surface electronic structure