Framework of Catalyst Layer Performance Modeling

Basically, a fuel cell electrode is a highly dispersed and heterogeneous interface between Pt nanoparticles and an electrolyte phase composed of acid-loaded ionomer and water. The structure is designed to maximize the interfacial area between catalyst and proton-supplying electrolyte. 

Random statistical composition, phase-segregated morphology, pore size distribution, and wetting properties of pores determine spatial distributions of potentials, concentrations of reactants, and liquid water saturation. A subtle electrode theory has to link these distributions with the overall CCL performance. 

This chapter focuses on steady-state phenomena during electrode operation. The structure that is formed during self-organization in catalyst layer inks and during MEA fabrication is considered to be constant. Unless stated otherwise, one-dimensional modeling approaches will be explored. This means that species transport occurs in through-plane direction only, perpendicular to the electrode plane. Moreover, in most part of this chapter, conditions are assumed to be isothermal. 

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