Strain-Enhanced Stabilization and Catalytic Activity of Metal Nanoclusters on Graphene

We report a first-principles investigation aiming at controlling the stabilization and catalytic activity of metal nanoclusters supported on graphene via tuning the mechanical strain in graphene. We show that a relatively modest tensile strain (10%) applied in graphene greatly increases the adsorption energies of various kinds of metal clusters under study by at least 100%, suggesting the greatly strain-enhanced stabilization of these metal clusters on graphene, which is highly desired for graphene-based catalysis. Using Au-16 and Au-8 clusters on graphene as model catalysts for CO oxidation, we found that a small strain of 5% in graphene reverses the charge transfer between Au clusters and graphene, and reduces the reaction barrier of the catalyzed CO oxidation from around 3.0 eV (without strain) to less than 0.2 eV. These findings provide new opportunities for future development of graphene-based nanocatalysis.