A highly-active, stable and low-cost platinum-free anode catalyst based on RuNi for hydroxide exchange membrane fuel cells.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33159046.
- Also identified by DOI 10.1038/s41467-020-19413-5 and PMC identifier 7648055.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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 Ru<sub>7</sub>Ni<sub>3</sub>/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 Ru<sub>7</sub>Ni<sub>3</sub>/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 Ru<sub>7</sub>Ni<sub>3</sub>/C anode can deliver a high peak power density of 2.03 W cm<sup>-2</sup> in H<sub>2</sub>/O<sub>2</sub> and 1.23 W cm<sup>-2</sup> in H<sub>2</sub>/air (CO<sub>2</sub>-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 Ru<sub>7</sub>Ni<sub>3</sub>/C. By using the Ru<sub>7</sub>Ni<sub>3</sub>/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.