Recovery of Pt and Ru from Spent Low-Temperature Polymer Electrolyte Membrane Fuel Cell Electrodes and Recycling of Pt by Direct Redeposition of the Dissolved Precursor on Carbon

Recovery of platinum group metals (PGMs), namely, Pt and Ru, from a spent membrane electrode assembly (MEA) of a low-temperature polymer electrolyte membrane fuel cell (PEMFC) through environmentally benign and scalable processes is of significant interest and strategic importance for sustainable growth of the renewable energy industries. Here, we report such a scalable and simple process for recovery of Pt and Ru from the spent MEAs from low-temperature PEMFCs, consisting of the Pt and PtRu nanoparticles supported on carbon (Pt/C and PtRu/C) as the cathode and anode electrocatalysts, respectively. The Pt and Ru were recovered through refluxing the MEA components in a mixture of 1 M HCl and H2O2 (1.5% v/v) with a dissolution efficiency >95%. Furthermore, Ru was separated from the dissolution bath in the form of Ru-hydroxide precipitates, while Pt was redeposited on a carbon support to form the recycled Pt/C electrocatalyst. Unlike conventional Pt/C synthesis, where a Pt compound is used as the Pt precursor, the process uses the dissolved Pt directly and hence eliminates steps necessary to recover it in the form of a Pt compound. The synthesized Pt/C exhibits an electrochemical surface area, particle size, and durability comparable to that of the commercial counterpart. The study is of substantial interest for sustainable development of the PEMFC and other relevant industries utilizing nanoparticulate PGMs for different applications.

Automated summary

The study presents a scalable and simple process for recovering Pt and Ru from spent MEAs of low-temperature PEMFCs. The recovered Pt and Ru showed high efficiency through refluxing in a mixture of 1 M HCl and H2O2, with Ru separated as Ru-hydroxide precipitates and Pt redeposited on a carbon support to form recycled Pt/C electrocatalysts, which exhibited comparable performance to commercial counterparts.