Degradation of PEMFC at low loadings

Our presentation focuses on investigations of durability and of degradation of fuel cells at low Pt loadings for automotive application. Major motivations are problems related to the need to reduce the amount of Pt in MEAs down to values of e.g. 0.2 mgPt/cm2 in order to make PEMFC more competitive. The particular challenge is to maintain sufficiently high performance and long-term durability. Both requirements, however, are conflicting with the reduction of Pt loading. In this context, our study regarding the influence of Pt loading on PEMFC performance and on durability shows that for cathode loadings below 0.2 mgPt/cm2 and for current densities exceeding 1 A/cm2 a sudden increase of mass transport resistance is observed. The same threshold value is found for the increase of irreversible voltage losses which lead to a dramatic reduction of PEMFC durability for cathodic loadings below 0.2 mgPt/cm2. Another durability issue at low cathodic Pt-loadings (