Highly Stable and Active Pt−Cu Oxygen Reduction Electrocatalysts Based on Mesoporous Graphitic Carbon Supports

Autor:	Steven Swinnea, Sheng Dai, Jaclyn D. Wiggins-Camacho, Pavan Kumar, Karren L. More, Keith J. Stevenson, Daniel A. Slanac, Xiqing Wang, Gaurav Gupta, Keith P. Johnston
Rok vydání:	2009
Předmět:	Materials science General Chemical Engineering Inorganic chemistry Nanoparticle chemistry.chemical_element General Chemistry Electrochemistry Oxygen Oxygen reduction Catalysis Direct energy conversion chemistry Materials Chemistry Particle size Mesoporous material
Zdroj:	Chemistry of Materials. 21:4515-4526
ISSN:	1520-5002 0897-4756
Popis:	The activity of oxygen reduction catalysts for fuel cells often decreases markedly (30−70%) during potential cycling tests designed to accelerate catalyst degradation. Herein we achieved essentially no loss in electrochemical surface area and catalyst activity during potential cycling from 0.5 to 1.2 V for presynthesized Pt−Cu nanoparticles of controlled composition that were infused into highly graphitic disordered mesoporous carbons (DMC). The high stability is favored by the strong metal−support interactions and low tendency for carbon oxidation, which mitigates the mechanisms of degradation. Electrochemical dealloying transforms the composition from Pt20Cu80 to Pt85Cu15 with a strained Pt-rich shell, which exhibits an enhanced ORR activity of 0.46 A/mgPt, >4 fold that of pure Pt catalysts. The high uniformity in particle size and composition both before and after dealloying, as a consequence of the presynthesis/infusion technique, is beneficial for elucidating the mechanism of catalyst activity and, u...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7dce5ef897ca7db8d92723c4bd263469 https://doi.org/10.1021/cm901203n Zobrazit plný text záznamu