Multifunctional Non-Pt ternary anode catalyst for reversal tolerant anode of automotive polymer electrolyte membrane fuel cell

Abstract

During the operation of a polymer electrolyte membrane fuel cell electric vehicle, various transient conditions may trigger hydrogen fuel starvation, which results in fatal degradation of anode caused by the reversal of the cell voltage. The reversal-tolerant anode (RTA) strategy has been introduced to mitigate the influence of hydrogen starvation. RTA employs a catalyst for the oxygen evolution reaction (OER), thereby facilitating the electrolysis of water and reducing the rate of carbon oxidation reaction. In this work, carbon-supported IrRu and IrRuY-based catalysts having the concurrent hydrogen oxidation reaction (HOR) and OER activity as RTA materials were prepared by various synthesis method (e.g., wet-impregnation, electron beam, and polyol process). Recently, IrRu-based alloy catalyst prepared by wet-impregnation as the RTA strategy has been proposed owing to its excellent activities for both HOR and OER. Total replacement of the Pt catalyst in the automotive PEMFC with an IrRu-based catalyst was suggested. In our previous study, to improve catalytic activity of IrRu-based catalyst and save usage of the precious metal, Y was incorporated into IrRu alloy to make IrRu4Y0.5 catalysts on carbon supports, using a novel approach such as an electron beam method was employed for the first time to prepare ternary IrRuY by using high energy electrons. In single cell test, the IrRu4Y0.5 delivers ~ 21% better performance and longer RTA durability (~ 64＆#8239;min) than Pt/C catalyst. Recently, carbon-supported IrRu catalysts with different compositions were synthesized by the polyol process. In particular, IrRu2/C catalyst exhibited HOR activity more than 116% compared withPt/C. In particular, under the fuel starvation condition, the RTA performance for IrRu2/C is the longest as ~7 h, compared with Pt/C (~ 10 min). In summary, it can suggest that the non-Pt anode catalysts (IrRu-based catalysts), which are a promising alternative candidate as an RTA catalyst for automotive PEMFC.