Modeling Elementary Heterogeneous Chemistry and Electrochemistry in Solid-Oxide Fuel Cells

This paper presents a new computational framework for modeling chemically reacting flow in anode-supported solid-oxide fuel
cells SOFC. Depending on materials and operating conditions, SOFC anodes afford a possibility for internal reforming or
catalytic partial oxidation of hydrocarbon fuels. An important new element of the model is the capability to represent elementary
heterogeneous chemical kinetics in the form of multistep reaction mechanisms. Porous-media transport in the electrodes is
represented with a dusty-gas model. Charge-transfer chemistry is represented in a modified Butler-Volmer setting that is derived
from elementary reactions, but assuming a single rate-limiting step. The model is discussed in terms of systems with defined flow
channels and planar membrane-electrode assemblies. However, the underlying theory is independent of the particular geometry.
Examples are given to illustrate the model.
© 2005 The Electrochemical Society. DOI: 10.1149/1.2116607 All rights reserved.