In response to global challenges concerning the ecological transition, the secure supply of critical raw materials, and the sustainable management of waste, the European Union has laid out an ambitious strategic vision through the European Green Deal. This initiative fosters a climate-neutral, resilient, and circular economy by promoting clean technologies and the recovery of valuable resources from complex waste streams such as waste electrical and electronic equipment (WEEE) and spent automotive catalysts. Within this framework, Regulation (EU) 2020/852 establishes a unified classification system for environmentally sustainable economic activities, guiding investment toward technologies for resource recovery and valorization.

The DURABLE project aligns with these strategic priorities by developing green and sustainable hydro-solvometallurgical processes for the recovery of key noble metals, gold (Au), platinum (Pt), and rhodium (Rh), from WEEE and end-of-life automotive catalysts (WCat). It addresses the technical and environmental challenges associated with extracting secondary raw materials from heterogeneous waste matrices, while minimizing the use of hazardous chemicals and energy-intensive conditions that typically characterize conventional methods.

This approach significantly contributes to the United Nations Sustainable Development Goals (SDGs), particularly those promoting good health and well-being (Goal 3), clean water and sanitation (Goal 6), responsible consumption and production (Goal 12), and climate action (Goal 13). In fact, pyrometallurgical recycling processes have been linked to adverse health effects and environmental degradation due to the release of hazardous emissions and substantial energy consumption. These impacts undermine progress toward several SDGs. In contrast, the closed-loop hydrometallurgical and adsorption-based route adopted in DURABLE promotes resource efficiency, enhances secondary raw material recovery, and reduces environmental burdens, offering a more sustainable alternative aligned with European and global policy goals.

The project not only enables the safe and efficient recovery of noble metals but also contributes to a tangible reduction in CO₂-equivalent emissions by avoiding high-temperature treatments and aggressive reagents. These advancements support both decarbonization efforts and the objectives of the 2030 Agenda for Sustainable Development.

By integrating selective leaching with adsorption-based refining, DURABLE seeks to optimize metal recovery in terms of both yield and selectivity. Depending on the characteristics of the sorbents used, metal-loaded materials can either undergo chemical regeneration or thermal recovery. This dual pathway allows for the industrial production of secondary metals or the direct reuse of sorbents as functional materials, including catalysts and electrodes for fuel cells.

The project also investigates the catalytic potential of recovered Pt and Au, particularly in the context of biorefinery applications. One notable case is the valorization of crude glycerol, a biodiesel by-product, through processes such as Aqueous Phase Reforming (APR) and selective oxidation to allylic alcohols. These applications demonstrate how waste valorization and functional material development can be effectively combined to advance the Union’s sustainability and circular economy objectives.

DURABLE is being implemented by a multidisciplinary consortium comprising experts from the Department of Chemical, Materials and Industrial Production Engineering (DICMAPI) at the University of Naples Federico II (UNINA) and the Institute of Science and Technology for Sustainable Energy and Mobility (STEMS) of the Italian National Research Council (CNR). This collaboration between academic and technological partners ensures the effective execution of the project and facilitates the transfer of its outcomes to the European industrial ecosystem.

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