Highly Active and Durable PGM-free ORR Electrocatalysts through the Synergy of Active Sites
Recipient Pacific Northwest National Lab/PNNL (PI: Shao, Yuyan)
Subs Prof. Vijay Ramani (Washington University in St. Louis), Prof. Liangbing Hu (University of Maryland, College Park), Dr. Dustin Banham (Ballard Power Systems Inc.)
Participating Labs PNNL
Abstract The overall goal of this project is to develop highly active and durable PGM-free catalysts for oxygen reduction reaction (ORR) in PEMFCs to meet DOE activity target (0.044A/cm2 at 0.9 V) as well as the potential to meet DOE durability target through dual-active site synergy, i.e., O2 reduction sites and H2O2 decomposition sites. The proposed novel mechanistic approaches can be strategically extended to any PGM-free ORR catalysts. In this project, the unique thermal shock activation technique with extremely fast heating/cooling (16,000K/s to 400,000K/s for up to 3000K) will be used to optimize and increase the density of both O2 reduction active sites and H2O2 decomposition active sites. By decreasing or eliminating H2O2 which has been shown to decrease electron transfer number and degrade catalysts and membrane/ionomers, the catalyst durability and activity will be increased. Innovation on hierarchical porous structure (e.g., nanowires, porosity, etc.) to facilitate mass transport will be achieved through controlling metal-organic framework (MOF) precursors structures/morphology. In collaboration with ElectroCat, our synergistic mechanism study will provide knowledge-based new catalyst design principles through dual site synergy. The materials innovation and fundamental study, with the aid of electrode engineering at membrane electrode assembly (MEA) level will lead us to meet DOE targets.