Simulating Gold’s Structure-Dependent Reactivity: Nonlocal Density Functional Theory Studies of Hydrogen Activation by Gold Clusters, Nanowires, and Surfaces

Gold’s
structure-dependent catalytic activity motivates
the study of reactions on a range of gold nanostructures. Electronic
structure methods used to model gold catalysis should be capable of
treating atoms, clusters, nanostructures, and surfaces on an equal
theoretical footing. We extend our previous density functional theory
(DFT) studies of a model reaction, H2 adsorption and dissociation
on unsupported Au3 clusters [J. Phys. Chem. C 2013, 117, 7487], to larger clusters, quasi-one-dimensional
nanowires and nanoribbons, and surfaces. We focus on trends in DFT
predictions made using various approximate exchange-correlation functionals.
Most functionals predict qualitatively reasonable trends, i.e., decreasing
adsorption energies and increasing dissociation barriers with increasing
Au coordination number. However, significant quantitative differences
motivate continued exploration of methods beyond the generalized gradient
approximation.