(564d) Tailoring Structure Sensitivity of Metal Nanoparticles on 2D and 3D Supports By Controlling Electrostatic Interactions at the Metal-Support Interface
AIChE Annual Meeting
Thursday, November 18, 2021 - 1:10pm to 1:30pm
The synergy between gold nanoparticles and oxide, carbide, nitride, sulfide supports promotes catalytic turnovers compared to when the gold and support are considered separately. This bifunctional gain is highly structure sensitive, being confined to interfacial active sites having specific coordination numbers (e.g., corners). Designing improved bifunctional interfaces is limited by two factors. First, we lack a systematic understanding of how the interface structure and composition influences catalytic properties. Second, we cannot precisely tailor structure sensitivity at interfaces such that a higher density of interfacial active sites participates in catalytic turnovers. Using a new class of site-specific scaling relations as a diagnostic tool, we holistically understand how the interfacial structure and composition influences adsorption energies of catalytic descriptors like CO*. We consider Au nanostructures ranging from single sites to epitaxial films supported on two- and three-dimensional carbides, oxides, sulfides, and nitrides. Thus, we include a wide latitude of interfacial perturbations. We classify site-specific scaling relations according to proximity to the interface, support termination, and support type. The scaling relations reveal that perturbations in adsorption energies of CO* caused by the interface are strongest for low coordinated interfacial sites located directly at the interface. This interfacial perturbation entirely decays at metal sites located beyond two lattice units from the interface. The scaling relation slopes represent changes in adsorption energies with variations in coordination numbers of interfacial Au sites, reflecting structure sensitivity. This structure sensitivity is highly tunable with interfacial modifications creating negatively charged Au sites being less structure sensitive. The decreased structure sensitivity increases the density of interfacial sites with similar catalytic properties, potentially boosting the overall rate per mass of precious metal. Validation tests demonstrate the predictive nature of our scheme with mean averaged errors of 0.11 eV. We conclude by applying this scheme to design next generation Au interfaces.