Manganese oxide nanowires (MONW) combined with carbon nanostructures were synthesized using three different carbon materials, and their effect on the activity towards Oxygen Reduction Reaction (ORR) and Oxygen Evolution Reaction (OER) was investigated in alkaline electrolytes. The carbon structures were carbon nanofibers (CNF), multiwall carbon nanotubes (CNT) and reduced graphene oxide (rGO). Both MONW and carbon nanostructures were characterized by X-ray diffraction, scanning and transmission electron microscopy, N₂ physisorption and X-ray photoelectron spectroscopy. The electrochemical activity was assessed in a three-electrode cell. Composite MONW/CNF showed the best activity towards ORR, and MONW/rGO exhibited the highest activity towards OER of the series. The addition of the carbon nanostructures to MONW increased the number of electrons transferred in the ORR, indicating a synergistic effect between the carbon and manganese oxide structures due to changes in the reaction pathway. The analysis of Tafel slopes and electrochemical impedance spectroscopies showed that carbons and MONW catalyze different steps of the reactions, which explains the better activity of the composites. This led us to synthesize a MONW/rGO-CNF composite, where rGO-CNF is a hybrid carbon material. Composite MONW/rGO-CNF showed an improved activity towards ORR, close to the benchmark Pt/C catalyst, and activity towards OER, close to MONW/rGO, and better than the benchmark IrO₂ catalyst. It also showed remarkable stability in challenging operation conditions.

The automotive sector is the third-largest consumer of plastics in Europe, after packaging and construction, and its demand is expected to grow. Plastic recycling at the end of vehicle life remains low, with 80% of plastics ending up in energy recovery or landfills. Three vehicle models (SEAT Ibiza Gen. IV and SEAT Leon Gen. II and III) with two trim versions (Reference and Formula Racing) were examined to identify the most critical plastic components from an exergy perspective. Ecodesign measures were defined by considering both the disassemblability of vehicle components and their recyclability potential as key criteria to evaluate end-of-life recovery pathways and guide material and design optimization strategies. The proposed methodology classified the measures into three types: (1) substitution of high-exergy plastics with lower-impact alternatives; (2) use of recycled plastics instead of primary materials, with substitution rates depending on the material; and (3) reuse of components in new models, evaluated by disassemblability and end-of-life condition. Results show that Type 1 measures achieved savings up to 70 MJ, mainly in the floor covering and engine compartment insulator, while Type 2 measures provided larger reductions, up to 1.7 GJ, mainly in bumpers and carpets. Type 3 measures showed reuse potential for paddings and insulators but faced limitations in carpets and dashboards. Findings highlight the importance of material selection and implementing disassembly and recycling strategies to reduce the exergy of vehicle plastics.