Thermophysical properties of adsorbates with beyond-DFT accuracy from DFT data through error cancellation.

Abstract

Predictive multiscale modeling of heterogeneously catalyzed reactions requires accurate enthalpies of adsorbates. These properties are typically calculated from density functional theory (DFT) using exchange-correlation functionals with the generalized-gradient approximation (GGA) since more accurate electronic structure methods are not feasible. Therefore, the derived enthalpies are subject to large inaccuracies. We address this challenge through an error-cancellation approach that builds on the connectivity-based hierarchy (CBH) to derive enthalpies of formation of adsorbates with beyond-DFT accuracy without increasing computational cost. This method constructs reactions that conserve the electronic configuration between the target and the reference species, leading to error cancellation. The method is applied to adsorbates on Pt(111), Ni(111), and MgO(100). With the CBH method, it is possible to determine enthalpies of formation that are in excellent agreement with experimental measurements for a range of adsorbates and across many GGA exchange-correlation functionals, clearly outperforming conventional referencing approaches. Additionally, the method combines available experimental surface science data with gas-phase thermochemistry data and DFT data in a global thermochemical network. More accurate enthalpies of formation have a tremendous impact on the predictive performance of multiscale models and enable more conclusive insights into reaction mechanisms of catalytic reactions.