Air-tolerant solar reforming of pre-treated biomass and plastics in viscous sustainable solvents

Abstract

We report an air-tolerant solar reforming (SR) system for the valorisation of pre-treated biomass and plastic waste streams. This process operates in low O₂-diffusivity solvents such as the robust deep eutectic solvent (DES) ZnCl₂-acetamide, which prevents O₂ from interfering with photocatalysis by avoiding easily oxidisable components (e.g. alcohols) in water. This approach sustains SR performance under aerobic conditions using a carbon nitride photocatalyst, enabling photooxidative valorisation of depolymerised cellulose and polyethylene terephthalate (PET) while generating H₂ fuel. SR using low O₂-diffusivity solvents is scalable and also adaptable to non-innocent viscous liquid wastes such as glycerol, which can act as both the low O₂-diffusivity solvent to exclude O₂ and the organic waste source to produce valuable chemicals.