CO adsorption on hydrogen saturated Ru(0001)

Abstract

The interaction of CO with the Ru(0001)(1×1)H surface has been studied by density functional theory (DFT) periodic calculations and molecular beam techniques. The hydrogen (1×1) phase induces an activation barrier for CO adsorption with a minimum barrier height of 25 kJ mol−1. The barrier originates from the initial repulsive interaction between the CO-4σ and the Ru-d3z2-r2 orbitals. Coadsorbed H also reduces the CO adsorption energy considerably and enhances the site preference of CO. On a Ru(0001)(1×1)H surface, CO adsorbs exclusively on the atop position.