We investigated the water-gas shift reaction over various active site models of a Pt/TiO2 catalyst from first principles, i.e., we considered as active site a Pt(111) model, an interface edge site of a Pt particle on a TiO2 support, an interface corner site of a Pt particle on a TiO2 support, an isolated Pt ion on a TiO2 support, and an isolated Pt atom on a TiO2 support surrounded by a Na10OxHy cluster. While predicting and correlating the activity for various active sites with experimental data, we considered the the uncertainty in computational predictions of the turnover frequency, apparent activation barrier, and reaction orders with a Bayesian model. Dependent on the reaction temperature, we find that different active sites are responsible for the observed kinetics. While at low temperature isolated Pt ions are most active, above 500 K interface edge sites dominate the observed kinetics in the experimental studies considered.

Identifying the active site of the water-gas shift reaction over platinum based catalysts

254th National Meeting (2017)

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