Simulating periodic trends in the structure and catalytic activity of coinage metal nanoribbons

Abstract

We present a systematic density functional theory (DFT) study of the structure and catalytic activity of group 10 (Ni, Pd, Pt) and group 11 (Cu, Ag, Au) coinage metal nanoribbons. These infinite, periodic, quasi-one-dimensional structures are conceptually important as intermediates between small metal clusters and close-packed metal surfaces, and have been shown experimentally to be practical catalysts. We find that nanoribbons have significantly higher predicted H2 dissociation activity than close-packed metal surfaces consistent with their lower coordination numbers. Computed periodic trends are reasonable, with late transition states and low barriers for H2 dissociation over late group 10 nanoribbons, suggesting their promise as practical catalysts. These trends are consistent with the isolated nanoribbons' computed molecular electrostatic potentials. Calculations also predict nearly linear Bronsted–Evans–Polanyi relationships between the nanoribbons' H2 dissociation energies and dissociation barriers. We also test new meta-generalized gradient approximation (GGA) and hybrid DFT approximations for H2 dissociation over these nanoribbons. These new functionals increase the (generally underestimated) dissociation barriers predicted by standard GGAs, motivating their continued application in surface chemistry. © 2015 Wiley Periodicals, Inc.