Analysis of Spatio-temporal Pattern Formation in a PEM Fuel Cell with Pt ∕ Ru Anode Exposed to H2 ∕ CO Mixtures

Abstract

In 2005 Zhang and Datta published a model for describing autonomous potential oscillations in a -catalyst-polymer electrolyte membrane (PEM) fuel cell operated with CO rich reformate [ J. X. Zhang and R. Datta , J. Electrochem. Soc. , 152 , A1180 (2005) ]. In the present contribution, we simplify a spatially extended version of this model in order to relate appearing pattern formation to electrochemical coupling mechanisms described by Krischer [ K. Krischer , in Advances in Electrochemical Science and Engineering, Wiley (2003) ]. It is concluded that mean-field- and migration-coupling are the fundamental mechanisms dictating pattern formation in the studied system. By artificially separating the electrical coupling terms it is found that large mean-field-coupling leads to a frequency entrainment and migration-coupling to a spatio-temporal intermittency scenario. It is argued that each of the situations can be found under realistic conditions, depending on the membrane conductivity and the system dimensions.