High surface area mesoporous carbon nanodendrites – detonation synthesis, characterization and use as a novel electrocatalyst support material

Abstract

Carbon supports play a crucial role in the performance and durability of the proton exchange membrane fuel cell (PEMFC). The porosity of carbon particles and the carbon matrix, as well as the surface area, is essential for good transport of oxygen, water and electrons. In this work, the synthesis and characterization of extremely high surface-area, mesoporous carbon nanodendrites (MCNDs) formed by controlled detonation are presented. This new carbon material is used as a cathode catalyst's support material in PEMFCs. Annealed at three different temperatures and compared to commercial carbon supports, the graphitization and ordering degree of the carbons are investigated. Pt nanoparticles are deposited on all support materials using a novel fluidized bed reduction reactor. MCND-based Pt nanoparticle fuel cell cathodes significantly outperform Pt catalysts on commercial carbons in single cell tests in PEMFCs. Online carbon degradation quantification reveals that, due to its unique porous structure and high surface area, corrosive high anodic cell potential cycling leads to pore collapse and hence should be avoided for this kind of support material. This behavior is reduced with higher annealing temperatures.