Innovative carbon nanotubes-bridging strategy valorizes plastic waste into high-quality H2-rich syngas while suppressing CO2 emissions

Abstract

Plastic waste disposal is mounting, with consequences for both environmental and human wellbeing. Addressing the plastic waste challenge through chemically upcycling waste to other products is gaining momentum but can have trade-offs. For example, the conversion of plastic waste into hydrogen rich gas can be achieved via catalytic steam, but this process can release large quantities of CO₂ (∼12 kg CO₂ per 1 kg H₂ production). High-performance bifunctional catalysts, such as carbon nanotubes (CNTs), offer a potential solution, but suppressing CO₂ emissions without compromising H₂-rich gas yield remains challenging. Here, we synthesize a new CNTs-bridging nanocomposite by integrating Ni nanoparticles with HY zeolite. Employing this bifunctional CNTs-bridging nanocomposite in the catalytic steam reforming of polyethylene can achieve high-quality H₂ yields of up to 2,340 mL/g_plastic and a 77% reduction in CO₂ emissions (1.68 g CO₂ per 1 g H₂ production). This work introduces an innovative CNTs-bridging strategy to valorize plastic waste into high-quality H₂-rich syngas while suppressing CO₂ emissions.