Advancing circular plastic valorization: A synthesis of catalytic, electrochemical, and thermal upcycling technologies for sustainable materials manufacturing

The global escalation of plastic waste necessitates a transition from conventional disposal toward advanced circular upcycling frameworks. This paper synthesizes recent progress in the valorization of plastic waste into high-value chemical feedstock, functional nanomaterials, and renewable energy carriers. Analysis of literature from 2020 through mid-2026 demonstrates that catalytic chemical depolymerization now achieves monomer yields and conversion efficiencies consistently exceeding 85% to 99%. Integrated electro-catalytic systems have emerged as high-performance platforms, frequently reaching Faradaic efficiencies above 90% for hydrogen and chemical intermediate production. Furthermore, high-energy plasma and thermal decomposition techniques have achieved substantial processing throughput, with hydrogen production rates often ranging from 50 to 170 mmol/g and liquid fuel yields reaching 50% to 90% in optimized trials. Beyond simple fuel production, the synthesis of advanced carbon-based materials from plastic precursors, such as quantum dots and hard carbons, has yielded electrochemical capacities frequently exceeding 300 to 400 mAh/g. Sustainability assessments highlight the potential for significant environmental impact, with life cycle analyses indicating greenhouse gas emission reductions of 30% to 85% relative to conventional manufacturing, alongside industrial-scale profit potentials reaching tens of millions of dollars annually. Despite these milestones, challenges such as feedstock heterogeneity and the stability of continuous industrial-scale operations remain. Future research must focus on scaling modular reactor designs, standardizing life cycle assessment metrics, and enhancing the resilience of catalytic systems against common plastic contaminants to accelerate the transition toward a net-zero, circular materials economy.