Experimental data and kinetic modeling of the catalytic and electrochemically promoted CH4 oxidation over Pd catalyst-electrodes

• The kinetic of the electrochemically promoted methane oxidation over Pd based catalyst-electrodes is studied.
• A model based on Langmuir–Hinshelwood mechanism predicts the kinetic.
• The model predicts the data under both open circuit state and polarization conditions.
• CH4 adsorption equilibrium constant increases with increasing applied anodic potential.

This aim of this work is to model the kinetics of the electrochemically promoted methane oxidation over impregnated Pd catalyst-electrodes in the temperature range between 300 and 400 °C. Six different kinetic models based on the Eley–Rideal, Langmuir–Hinshelwood and Mars van Krevelen mechanisms were fitted to the experimental data. It was found that Langmuir–Hinshelwood mechanism, considering dissociative chemisorption of O2 and only one oxygen surface species consumed in the rate determining step, successfully predicted the kinetics of the methane consumption rate under both open circuit state and electrochemical promotion conditions. In addition, the influence of the polarizations on the components adsorptions was analyzed. An increase in the adsorption constant and the partial charge transfer parameter of the methane was obtained with increasing values of the applied anodic potential.