Enhanced activity and durability for the electroreduction of oxygen at a chemically ordered intermetallic PtFeCo catalyst

• DOI: 10.1039/c4ra04744c
• Publication Date: 2014-06-06T12:35:07Z
• Authors: Balamurugan Arumugam; Bhalchandra A. Ka...; Takanori Tamaki; Masazumi Arao; Hideto Imai; Takeo Yamaguchi
• Keywords: Tetragonal crystal system

We have designed a chemically ordered face-centred tetragonal intermetallic PtFeCo (trimetallic) (fct-TM) alloy catalyst using simple solid-state impregnation method for the oxygen–reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs). The fct-TM has demonstrated both enhanced activity and durability, unlike many Pt alloys. chemical ordering of was verified by high-angle annular dark-field scanning transmission electron microscopy. ORR examined rotating-disk electrode (RDE) technique results are compared with those disordered cubic (fcc), fcc-TM catalyst, commercial from Tanaka Kikinzoku Kogyo, TKK-PtC. displayed superior catalytic (mass) relative to mass (0.505 A mgPt−1) is 2.5 times higher than that TKK-PtC (0.23 mgPt−1). durability these catalysts evaluated over 5000 (5k) potential cycles lifetime regime. retained 80% its initial electrochemically active surface area (ECSA); however, maintained about 50% 70% activity, respectively. also structure after 5k cycles. This confirmed selected-area electron-diffraction (SAED) patterns. Furthermore, microscopy-energy dispersive X-ray spectroscopy (STEM-EDX) line scans revealed Fe Co were found similar as before cycling, which signifies dissolution impeded catalysts. observed enhancement might be due arrangement Fe/Co within alloy.