Skip to content

Mechanism of the water gas shift reaction on Pt: First principles, experiments, and microkinetic modeling

by Lars C. Grabow, Amit A. Gokhale, Steven T. Evans, James A. Dumesic, Manos Mavrikakis
Journal of Physical Chemistry C ()
Get full text at journal


We present a microkinetic model as well as experimental data for the low-temperature water gas shift (WGS) reaction catalyzed by Pt at temperatures from 523 to 573 K and for various gas compositions at a pressure of 1 atm. Thermodynamic and kinetic parameters for the model are derived from periodic, self-consistent density functional theory (DFT-GGA) calculations on Pt(111). The destabilizing effect of high CO surface coverage on the binding energies of surface species is quantified through DFT calculations and accounted for in the microkinetic model. Deviations of specific fitted model parameters from DFT calculated parameters on Pt(111) point to the possible role of steps/defects in this reaction. Our model predicts reaction rates and reaction orders in good agreement with our experiments. The calculated and experimental apparent activation energies are 67.8 kJ/mol and 71.4 kJ/mol, respectively. The model shows that the most significant reaction channel proceeds via a carboxyl (COOH) intermediate. Formate (HCOO), which has been experimentally observed and thought to be the key WGS intermediate in the literature, is shown to act only as a spectator species.

Cite this document (BETA)

Authors on Mendeley

  1. Lars Grabow
    Assistant Professor
    Department of Chemical and Biomolecular Engineering, University of Houston

Readership Statistics

154 Readers on Mendeley
by Discipline
41% Chemistry
38% Engineering
7% Chemical Engineering
by Academic Status
42% Student > Ph. D. Student
22% Researcher
11% Student > Master
by Country
6% United States
1% United Kingdom
1% Brazil

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Sign up & Download

Already have an account? Sign in