Low-Temperature Synthesized Pt<sub>3</sub>Fe Alloy Nanoparticles on Etched Carbon Nanotubes Catalyst Support Using Oxygen-Deficient Fe<sub>2</sub>O<sub>3</sub> as a Catalytic Center for PEMFC Applications
Dipsikha Ganguly, Kothandaraman Ramanujam, Sundara Ramaprabhu
Abstract
Proton exchange membrane fuel cells (PEMFCs) have emerged as one of the most promising next-generation renewable energy technologies for the future. However, for the commercialization of PEMFC, low loading of Pt-based catalysts with suitable catalyst support is the utmost necessity. Pt alloys are useful for achieving good electrochemical activity with low Pt loading. But, high-temperature synthesis of these alloys leads to lower cyclic stability. Herein, we have synthesized Pt 3 Fe alloy on etched carbon nanotubes at low-temperature using oxygen-deficient Fe 2 O 3 -ECNT. This low-temperature synthesized Pt 3 Fe-ECNT shows excellent electrocatalytic activity due to the change in the d-band center and lattice contraction in the bimetallic alloy system. Lower hydrogen binding energy, increases in the electrochemical surface area (84 ± 3 m 2 g –1 ) and mass activity (0.45 A mg Pt –1 ) of the Pt 3 Fe-ECNT catalyst, compared to commercial Pt/C (0.36 A mg Pt –1 ), confirms it to be a better catalyst for PEMFC. Furthermore, single-cell studies also show promising performance under real PEMFC conditions. A maximum power density of 530 mW cm –2 at 60 °C is achieved with Pt loading far lower than the U.S. Department of Energy (DOE) 2020 target (0.125 mg Pt cm –2 ) with an excellent Pt catalyst utilization and fast kinetics. After an accelerated durability test of 10 000 cycles, stability studies substantiate it as a suitable catalyst for PEMFC applications.