(36a) Single Atom Catalysts Supported on Defective Hexagonal Boron Nitride: Stability and Activity for CO Oxidation

Authors: 
Schimmenti, R., University of Wisconsin-Madison
Mavrikakis, M., University of Wisconsin-Madison
Atomically dispersed metal catalysts, such as supported single atom catalysts (SACs), have recently gained increased interest in the catalysis community [1]. Due to their monodispersity, SACs demonstrate unique selectivity with respect to their nano-sized counterparts [2].

The efficient synthesis of SACs, requires the use of strongly binding supports, which are able to stabilize the atomic species and avoid sintering at operating reaction conditions. For example, oxygen-defective metal oxides, such as MgO [3] or CeO2 [4], were proposed as potential strongly binding supports for Pd and Pt, respectively. However, SACs supported on metal oxides having highly endothermic oxygen vacancy formation energies, are easily prone to deactivation in oxidizing reactive environments, due to vacancy healing by oxygen [5]. Therefore, supports other than metal oxides may be better suited for SACs for oxidation reactions.

In this study, we employ density functional theory (DFT) calculations for evaluating the potential use of defective hexagonal boron nitride (h-BN) monolayers as supports for SACs. We have systematically screened the stability of more than two dozens transition and post-transition metal atoms, considering different h-BN defect topologies, including N or B vacancies.

We identified several potential candidates leading to the formation of stable SACs supported on defective h-BN. The catalytic activity of these is studied for CO oxidation.

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