Identification of the environmental hotspots of a recycling process - Case study of a Pt PEMFC catalyst closed-loop recycling system evaluated via life cycle assessment methodology

Abstract

Proton-exchange membrane fuel cell (PEMFC) technology using green H2 as a fuel to produce decarbonized electricity is considered as a promising substitute for fossil fuels. However, its development is impeded by the use of critical raw materials, such as platinum which catalyzes the hydrogen oxidation and oxygen reduction reactions. In this paper, a novel closed-loop system for the re-manufacturing of platinum-based catalyst electrode from recycled material is developed. Three different recycling alternatives are compared using the life cycle assessment (LCA) methodology. The most promising one, which combines the extraction step with an innovative synthesis of recycled Pt/C catalyst, leads to the manufacturing of an electrochemically active Pt/C catalyst with a high recovery efficiency of 96 %. Sensitivity analyses display that the recycling processes significantly relieve the environmental burdens associated with platinum mining and that their efficiencies directly relate to a decrease in environmental impacts.