Publication Date:
2018
Description:
〈p〉Achieving high catalytic performance with the lowest amount of platinum is critical in fuel cell cost reduction. We describe a method of preparing highly active yet stable electrocatalysts containing ultralow Pt content using Co or Co/Zn zeolitic imidazolate frameworks as precursors. Synergistic catalysis between strained Pt-Co core-shell nanoparticles over a platinum-group-metal-free (PGM-free) catalytic substrate led to excellent fuel cell performance under 1 atmosphere of O〈sub〉2〈/sub〉 or air at both high voltage and high current domains. Two catalysts achieved the oxygen reduction reaction (ORR) mass activities of 1.08 A mg〈sub〉Pt〈/sub〉〈sup〉–1〈/sup〉/1.77 A mg〈sub〉Pt〈/sub〉〈sup〉–1〈/sup〉 and retained 64%/15% of initial values after 30,000 voltage cycles in fuel cell. Computational modeling reveals that the interaction between Pt-Co and PGM-free sites improves ORR activity and durability.〈/p〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Natural Sciences in General