LAUSR

Abstract Bimetallic surface alloys have been considered as an effective strategy to achieve better catalytic performance and to modify the work function of the substrate toward metal-gate electrode application. We perform a systematical investigation of Group 10 and Group 11 transition metals adsorption on Rh (111), Ru (0001) and W (110) surfaces with various coverages using first-principles method. Through comparing the Bader charge results and the plots of work function shift, it is found that the polarization effect plays an important role in modification of the bimetallic surface work functions rather than the charge transfer effect especially at low coverages. The coverage-dependent work function behavior gives a general feature: as it has a large negative shift at 0.25ML coverage, then increases almost linearly with the coverage and followed by a saturation value which is controlled by the lattice strain. It is also found that the metal over-layer growth modes are correlated with the specific features of the coverage-dependent metal-substrate adhesion energy. All these findings may give some guidelines for the bimetallic catalysts design in terms of growth, stability and activity.