Design of Pt/Carbon Xerogel Catalysts for PEM Fuel Cells

Abstract

Abstract:The design of efficient catalytic layers of proton exchange membrane fuel cells (PEMFCs) requires the preparation of highly-loaded and highly-dispersed Pt/C catalysts. During the last few years, our work focused on the preparation of Pt/carbon xerogel electrocatalysts, starting from simple impregnation techniques that were further optimized via the strong electrostatic adsorption (SEA) method to reach high dispersion and a high metal weight fraction. The SEA method, which consists of the optimization of the precursor/support electrostatic impregnation through an adequate choice of the impregnation pH with regard to the support surface chemistry, leads to very well-dispersed Pt/C samples with a maximum 8 wt.% Pt after drying and reduction under H2. To increase the metal loading, the impregnation-drying-reduction cycle of the SEA method can be repeated several times, either with fresh Pt precursor solution or with the solution recycled from the previous cycle. In each case, a high dispersion (Pt particle size ~3 nm) is obtained. Finally, the procedure can be simplified by combination of the SEA technique with dry impregnation, leading to no Pt loss during the procedure.

Electrocatalysis in Fuel Cells

“…Holade et al [29] and Job et al [30] summarized the recent advances in the preparation of carbon-supported nanocatalysts based on colloidal methods. The correlation between the structure of the catalysts and their activities and the effects from the synthesis methods were discussed.…”

Electrocatalysis in Fuel Cells

“…The performance of fuel cell catalysts is certainly dependent on the preparation methods. Holade et al [29] and Job et al [30] summarized the recent advances in the preparation of carbon-supported nanocatalysts based on colloidal methods. The correlation between the structure of the catalysts and their activities and the effects from the synthesis methods were discussed.…”

Toward a continuous synthesis of porous carbon xerogel beads

“…These materials have a high surface specific area, display a tailorable pore texture and are good conductors of electricity . Therefore, they can be used in a wide range of industrial applications as adsorbents, catalyst supports, and battery or fuel cell electrodes . The original process developed by Pekala is not applicable on a large scale because it involves long aging time of the gel and supercritical drying.…”