First Principles Investigation of Reversible Adsorption/Desorption and Molecular Dissociation of $CO_{2}$ on Ferroelectric $PbTiO_{3}$-supported $ZnO$ Thin Films

Applying an electric field across a ferroelectric changes its polarization direction. When epitaxial layers are grown on such materials, the polarization may induce new atomic configurations at the interface. In this paper, we use density functional theory calculations to demonstrate that this effect can be used to reversibly modify the surface chemistry of thin $ZnO$ grown on ferroelectric $PbTiO_{3}$. We show that both the substrate polarization direction and the thickness of the $ZnO$ film have a significant effect on the adsorption energy of $CO_{2}$ and methanol, indicating that dynamic polarization switching could be used to minimize reaction barriers and/or enhance selectivity. As an example, we demonstrate a pathway for thermal $CO_{2}$ dissociation over a single monolayer of $ZnO$ on $PbTiO_{3}$ with a predicted reaction rate several orders of magnitude higher than that over unsupported $ZnO$. Our results suggest that ferroelectric-supported $ZnO$, and dynamically tunable catalysts in general, could enable lower-energy approaches for $CO_{2}$ conversion.