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Kinetics of the Anode Processes in PEM Fuel Cells – The Promoting Effect of Ru in PtRu Anodes
Author(s) -
Liu P.,
Nørskov J. K.
Publication year - 2001
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/1615-6854(200112)1:3/4<192::aid-fuce192>3.0.co;2-m
Subject(s) - anode , proton exchange membrane fuel cell , electrochemistry , adsorption , hydrogen , kinetics , exchange current density , materials science , inorganic chemistry , chemistry , chemical engineering , electrode , thermodynamics , catalysis , organic chemistry , physics , quantum mechanics , engineering , tafel equation
A kinetic model for the anode processes in low temperature proton exchange membrane fuel cells with a Pt based anode is developed. The model is as simple as possible with the minimum number of parameters, and most are determined directly from density functional calculations of adsorption energies. It is first shown that the electrochemical CO oxidation process is described well by the model. In particular, the effect of alloying the Pt electrode with Ru is predicted directly based on the calculated effect of alloying Pt with Ru on the adsorption properties of the surface. The model also describes the hydrogen oxidation process and the effect of CO in the feed gas well. The model predicts the experimentally observed promoting effect of Ru with no fitting to experimental data. It is then used to evaluate whether the promoting effect of Ru is due to the ligand effect or the bifunctional effect. For the CO oxidation process the model suggests that there is a contribution from both effects, but for the hydrogen oxidation process only the ligand effect is important.