The objective of this work is to understand the unique catalysis of the three-phase boundary (TPB) of TiO2 supported Pt catalysts for the water-gas shift (WGS).  The mechanism of the WGS at the Pt/TiO2 interface has been investigated using plane wave DFT calculations by considering the following pathways: (i) redox pathway, (ii) associative carboxyl pathway, and (iii) associative carboxyl with redox regeneration route. Analysis of a microkinetic model containing all these pathways indicates that the CO promoted redox pathway is the most favorable pathway with the lowest activation barrier and highest rate. The calculated apparent activation barrier and reaction orders for this pathway are in excellent agreement with experimental values. In general, this study reveals that the Pt sites away from the TPB likely act primarily as a CO reservoir and the oxide support plays an essential role in O-H bond breaking and H-atom transfer to the metal surface.

Combined DFT and microkinetic modeling study of the water-gas shift reaction at the three phase boundary of Pt/TiO<sub>2</sub> catalysts

245th National Meeting (2013)

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Combined DFT and microkinetic modeling study of the water-gas shift reaction at the three phase boundary of Pt/TiO2 catalysts

Combined DFT and microkinetic modeling study of the water-gas shift reaction at the three phase boundary of Pt/TiO₂ catalysts