Microwave-initiated catalytic deconstruction of plastic waste into hydrogen and high-value carbons

The ubiquitous challenge of plastic waste has led to the modern descriptor plastisphere to represent the human-made plastic environment and ecosystem. Here we report a straightforward rapid method for the catalytic deconstruction of various plastic feedstocks into hydrogen and high-value carbons. We use microwaves together with abundant and inexpensive iron-based catalysts as microwave susceptors to initiate the catalytic deconstruction process. The one-step process typically takes 30–90 s to transform a sample of mechanically pulverized commercial plastic into hydrogen and (predominantly) multiwalled carbon nanotubes. A high hydrogen yield of 55.6 mmol $${\mathrm{g}}_{\mathrm{plastic}}^{ - 1}$$ is achieved, with over 97% of the theoretical mass of hydrogen being extracted from the deconstructed plastic. The approach is demonstrated on widely used, real-world plastic waste. This proof-of-concept advance highlights the potential of plastic waste itself as a valuable energy feedstock for the production of hydrogen and high-value carbon materials. The valorisation of plastic waste is highly desirable from an environmental perspective but generally yields low-value products. Now a method is disclosed to deconstruct plastic feedstocks into high-value hydrogen and carbon materials by means of an iron-based catalyst under microwave irradiation.