A locally resolved investigation on direct methanol fuel cell uneven components fading: Steady state and degradation local analysis

A locally resolved investigation on direct methanol fuel cell uneven components fading: Local cathode catalyst layer tuning for homogeneous operation and reduced degradation rate

“…Analogously to [29], anode catalyst layer (ACL) is loaded with 1.8 mg•cm -2 (PtRu alloy), while cathode catalyst layer (CCL) is provided with locally variable catalyst and ionomer loading, as discussed in section 4.1, corresponding to 1.2 mg•cm -2 (Pt) average. For CCL, a highly graphitized carbon support with 0.5 Pt:C ratio is adopted consistently with [29], where the stability of this component was discussed in AST and DMFC operation. On both sides Sigracet® SGL35DC GDLs (thickness 325 µm, 20% PTFE content) provided with microporous layer (MPL) are used, while membrane is Nafion® 115 (127 µm thick).…”

“…The local experimental setup, thoroughly discussed in [29] and briefly summarized in the following, permits local detailed analysis of performance and degradation. A macro-Segmented Fuel Cell (m-SFC) hardware [29] is utilized in the experimental activity, featuring an active full control on four macro-regions of the cell.…”

“…The local experimental setup, thoroughly discussed in [29] and briefly summarized in the following, permits local detailed analysis of performance and degradation. A macro-Segmented Fuel Cell (m-SFC) hardware [29] is utilized in the experimental activity, featuring an active full control on four macro-regions of the cell. It enables complete electrochemical characterization of each segment while limiting internal border effects, avoiding crosscurrents and reciprocal interference between segments; the limited invasiveness of the setup has been demonstrated in [29].…”

“…Based on results obtained in [29], the most critical components to focus on for the local properties optimization could be either CCL and GDL, both in terms of formulation and microstructure, to face locally dehydrating as well as flooding conditions. In literature, several studies on PEMFC optimization [33][34][35][36][37][38] were identified as useful to obtain insights helping the optimization strategy to be pursued in this work, among which very few discuss DMFC technology.…”

“…Hence, in this work catalyst, ionomer and carbon loading will be locally shaped to promote operation in the performance limited regions identified, e.g. cathode inlet and outlet [29]. Local catalyst loading profile will be tuned by means of physical modelling simulation, aiming to a uniform current density distribution at the nominal operating point.…”