The structural and catalytic properties of three-phase boundaries, which exist at the interface between supported metal nanoparticles and oxide substrates, have recently attracted significant attention in both fundamental and applied catalytic studies.  These structures have been shown, in some cases, to dominate the reactivity of supported metal nanoparticles, but the mechanisms by which they enhance the reactivity, as well as strategies to tune their properties, remain largely unknown.  In this talk, we describe recent efforts in our group to model catalytic reactions at the interface between gold nanoparticles and doped MgO substrates. We analyze the water-gas shift reaction and simple oxidation reactions, and we describe the development of computational strategies to combine detailed DFT calculations with microkinetic modeling for these chemistries.  Next, we demonstrate how dual site reaction models can describe these reactions, and we elucidate the promotional effect of the metal/oxide interface on the indicated kinetics.  Simple strategies to tune the catalytic reactivity of the Au/MgO system through electronic doping of the oxide are then presented, and the existence of rigorous scaling relationships for species adsorbed at the metal/doped oxide interfaces is established.  These scaling relationships are, in turn, used to develop reactivity trends, in the form of classical volcano plots, for the bifunctional systems.  The talk will conclude with perspectives on the use of these strategies for computational design of other chemistries that preferentially occur at metal/oxide interfaces.

First principles analysis of reactivity trends at metal/oxide interfaces

2019 Spring National Meeting

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