Gradation of mechanical properties in gas diffusion electrode. Part 1: Influence of nano-scale heterogeneity in catalyst layer on interfacial strength between catalyst layer and membrane

Stress and plastic deformation analyses of catalyst layer have been conducted after experimentally investigating its mechanical properties at nano-scale. Interestingly, catalyst layer is found to have varying mechanical properties as a function of depth and therefore it is classified under graded material. Effect of gradation in catalyst layer on interfacial strength between membrane and catalyst layer is explained with the aid of numerical simulations. Stress redistribution near interface line is observed in graded model, while stresses are found to have concentrated at critical locations throughout the discrete model. However, it is outlined from this study that the gradation in catalyst layer leads to greater amount of plastic energy dissipation—an indication of enhanced ductility. An experimental coupled numerical approach is presented to characterize the effect of transitional variations of mechanical properties in catalyst layer on the interfacial line and membrane.