A highly-active, stable and low-cost platinum-free anode catalyst based on RuNi for hydroxide exchange membrane fuel cells

Yanrong Xue,Yushan Yan,Xingdong Wang,Wei Zhu,Jinjie Fang,Zhongbin Zhuang,Xuerui Liu,Brian P Setzler,Lin Shi

doi:10.1038/s41467-020-19413-5

Abstract

The development of cost-effective hydroxide exchange membrane fuel cells is limited by the lack of high-performance and low-cost anode hydrogen oxidation reaction catalysts. Here we report a Pt-free catalyst Ru7Ni3/C, which exhibits excellent hydrogen oxidation reaction activity in both rotating disk electrode and membrane electrode assembly measurements. The hydrogen oxidation reaction mass activity and specific activity of Ru7Ni3/C, as measured in rotating disk experiments, is about 21 and 25 times that of Pt/C, and 3 and 5 times that of PtRu/C, respectively. The hydroxide exchange membrane fuel cell with Ru7Ni3/C anode can deliver a high peak power density of 2.03 W cm−2 in H2/O2 and 1.23 W cm−2 in H2/air (CO2-free) at 95 °C, surpassing that using PtRu/C anode catalyst, and good durability with less than 5% voltage loss over 100 h of operation. The weakened hydrogen binding of Ru by alloying with Ni and enhanced water adsorption by the presence of surface Ni oxides lead to the high hydrogen oxidation reaction activity of Ru7Ni3/C. By using the Ru7Ni3/C catalyst, the anode cost can be reduced by 85% of the current state-of-the-art PtRu/C, making it highly promising in economical hydroxide exchange membrane fuel cells.

Highlights

The development of cost-effective hydroxide exchange membrane fuel cells is limited by the lack of high-performance and low-cost anode hydrogen oxidation reaction catalysts
Recent reports show that Ru enhances the hydrogen oxidation reaction (HOR) activity of PtRu/C catalyst which has the highest activity in HEMFCs29,30
Ru is considered as the HOR active sites for the Ru7Ni3/C catalyst because of its metallic form in the HOR process

Summary

Introduction

The development of cost-effective hydroxide exchange membrane fuel cells is limited by the lack of high-performance and low-cost anode hydrogen oxidation reaction catalysts. By using the Ru7Ni3/C catalyst, the anode cost can be reduced by 85% of the current state-of-the-art PtRu/C, making it highly promising in economical hydroxide exchange membrane fuel cells. If HEMFCs can maintain high performance without using Pt, low-cost fuel cells can be realized, significantly advancing the hydrogen economy They showed high activity and potential to replace the Pt-based cathode catalysts in HEMFCs. the hydrogen oxidation reaction (HOR) still relies on Pt-based catalysts. The development of low-cost and high-activity anode catalysts is required to fulfill the commercialization of HEMFCs. Some non-platinum HOR catalysts have been reported, such as. HEMFC using Ru/C as anode catalyst can only output a PPD of ca. 250 mW cm−2 31

Methods

Results

Conclusion