(175e) Uncertainty Quantification of a Computational Study of the Water-Gas Shift Reaction Catalyzed By Platinum Clusters Supported on Titanium Oxide (Pt/TiO2)

The water-gas shift reaction is the primary reaction for generating hydrogen for the chemical and petrochemical industries.  In this paper a novel uncertainty quantification study is conducted of a computational model of the water-gas shift reaction occurring at the three-phase boundary of a Pt/TiO₂ catalyst by taking into account the inexact nature of density functional theory and constraining the results to thermodynamic experiments.  This uncertainty quantification study provides informative model results in the presence of errors from DFT.  The first objective of uncertainty quantification is to make reliable model results given such possible errors.  A second objective is constraining density functional theory results to thermodynamic experiments.  The thermodynamic constraints are accomplished by causing gas molecule corrections to sum to a constant amount.  CO is given a large adjustment compared to other gas molecules due to prior knowledge about the PBE functional being unable to correctly describe the electronic structure of CO.  Uncertainty in model results is represented by probability density plots and the dominant catalytic cycle is identified.