Influence of operational parameters and of catalytic materials on electrical performance of Direct Glycerol Solid Alkaline Membrane Fuel Cells
Résumé
The present study focused on the improvement of some aspects of the membrane electrode assembly (MEA) fabrication and on some working conditions of the SAMFC (Solid Anionic Membrane Fuel Cells) fed with glycerol. The fuel solution composition has a great importance. Higher performances were achieved with 1 M glycerol +6 M NaOH solution composition. Further increase of the glycerol concentration led to transport limitations due to the increasing of the mixture viscosity. The electrical performance of a SAMFC reached the maximum value with a glycerol flow of 10 mL min(-1); the oxygen flow rate displayed no significant influence on the electrical performance. The temperature has a great effect on the fuel cell performance. The anion exchange membrane available in the present study led to higher performance in the temperature range between 60 and 70 degrees C. The fuel cell measurements performed with monometallic Pt/C. Pd/C materials, and bimetallic PtPd/C, PtBi/C and PdBi/C compounds as anode catalysts showed encouraging results with respect to the decrease of platinum loading and elaboration of Pt-free catalysts. Low platinum loaded Pt5Pd5/C and non-platinum based Pd9Bi1/C catalysts allowed reaching fuel cell performances very close or even higher than those obtained with a Pt/C catalyst at 25 degrees C and 60 degrees C.