2018 AIChE Annual Meeting

(269e) How Do DFT+U and Hybrids Alter Widely Applied Linear Scaling Relations in Heterogeneous Catalysis?

Authors

Zhao, Q. - Presenter, Massachusetts Institute of Technology
First-principles electronic structure calculations (e.g. with density functional theory or DFT) provide unique insights into computational materials and catalyst design. However, the approximations made in semi-local DFT models suffer from delocalization error that prevents predictive accuracy on the most compelling materials to study computationally, such as transition metal catalysts. Within surface chemistry, energetics of adsorbates and surfaces will be sensitive to the relative degree of delocalization permitted in a coordination geometry. Thus, more strongly coordinating geometries will be stabilized over weakly interacting ones, and adsorption energies will be overestimated. We carry out a systematic study to identify commonalities in how diverse approaches for approximate delocalization error correction (i.e., DFT+U and hybrid functionals) perform on adsorption energies and surface formation energies of catalytically active, correlated transition metal oxide surfaces. We will present periodic-table-dependent, method-dependent, divergent behaviors on representative rutile-type transition metal dioxides, which are widely employed as catalysts for water splitting. We will discuss how these approaches alter linear scaling relations between different intermediates, and thus identifying materials at the top of the “volcano” maximum in activity. Time permitting, we will also present our observations on how these same delocalization error corrections alter essential properties of the density in correlated solids.