PtRu alloy nanoparticles supported on high surface area carbon (PtRu/C) are common electrocatalysts used for the hydrogen oxidation reaction at polymer electrolyte membrane fuel cell (PEMFC) anodes. Recycling of these precious metals at the end of the lifetime of fuel cells is important for their further applications in a sustainable energy technology scenario. In this study,1 we explore the electrochemical dissolution of Pt and Ru from the PEMFC anode catalyst layer, i.e., a PtRu alloy supported on carbon catalyst (PtRu/C). Effects of different dissolution routes on the relative rates of dissolution for Pt and Ru have been explored with different electrolytes, namely 0.1 M HCl and 1 M H2SO4. Apart from studying the effect of the presence of chloride on their stability, this study explores the electrochemical dissolution-based recovery of Pt and Ru from PtRu/C electrocatalysts. During potential cycling in presence of chloride (0.1 M HCl), the stability of Pt is observed to be lower than that of Ru. On the other hand, in absence of chloride, due to redeposition of the instable dissolved species, Pt shows stability higher than Ru. For example, the % dissolutions of Pt and Ru are observed to be ~72% and ~33% during potential cycling between 0.2 and 1.6 V for 50 cycles at a scan rate of 100 mV/s, in 0.1 M HCl. On the other hand, for similar initial Pt and Ru loadings, the corresponding dissolution values for Pt and Ru after potential cycling between 0.2 and 1.6 V for 10k cycles at a scan rate of 1 V/s in 1 M H2SO4 are observed to be ~27% and ~61%, respectively (Figure 1). This difference of behaviors is attributed to the formation and stability of soluble Pt and Ru species during potential cycling. The fast dissolution of Pt and higher stability of Ru found during potential cycling in dilute HCl may be explored towards separation of Pt and Ru and for separable recoveries from spent alloy catalysts.
|Publikationsdato||30. aug. 2020|
|Status||Udgivet - 30. aug. 2020|
|Begivenhed||71st Annual Meeting of the International Society of Electrochemistry: Electrochemistry towards Excellence - Online, Belgrade, Serbien|
Varighed: 30. aug. 2020 → 4. sep. 2020
|Konference||71st Annual Meeting of the International Society of Electrochemistry|
|Periode||30/08/2020 → 04/09/2020|