Plasma-driven catalytic process for plastic waste upcycling over perovskite-type pre-catalysts

• Plasma-thermal catalytic tandem process for fast decomposition of plastic waste with a high H 2 yield of 54.7 mmol/g plastic. • Catalyst morphology’s impact on H 2 and carbon nanomaterial production yields. • Systematic comparison between plasma-thermal catalytic and conventional thermal catalytic processes. • LCA results demonstrate the environmental benefits of the ultrasonic spray method for catalyst synthesis. The increasing demand for plastics poses significant challenges for post-consumer waste management. In this work, we propose a novel plasma-thermal catalytic tandem process over perovskite-type La 0.6 Ca 0.4 Co 1– x Fe x O 3− δ (LCCF) pre-catalysts for upcycling plastic waste into H 2 and value-added metal oxide–carbon composite materials. Among the evaluated pre-catalysts, La 0.6 Ca 0.4 Co 0.2 Fe 0.8 O 3− δ prepared by ultrasonic spray synthesis (USS) demonstrated the highest performance, achieving an H 2 yield of 54.7 mmol/g plastic (∼76.6 % of theoretical H 2 production) with a selectivity of 78 %. Morphological differences between pre-catalysts synthesized via USS and co-precipitation appear to play a crucial role in their catalytic efficiency. Life cycle assessment results indicate that the ultrasonic spray synthesis method is more environmentally sustainable than the co-precipitation method for LCCF production. Considering the high H 2 yield during plastic upcycling using the La 0.6 Ca 0.4 Co 0.2 Fe 0.8 O 3− δ pre-catalyst prepared by USS, along with its lower environmental impact during pre-catalyst production compared to the co-precipitation method, the plasma-thermal catalytic tandem process using this pre-catalyst offers a promising and sustainable approach to plastic waste upcycling.