TiO2-Supported Ru–Fe Catalysts for the Hydrodeoxygenation of Bis(2-hydroxyethyl) Terephthalate (BHET) Prepared by the Glycolysis of Polyethylene Terephthalate (PET)

Abstract

Polyethylene terephthalate (PET) upcycling to petrochemical feedstocks proceeded through catalytic hydrodeoxygenation (HDO) of bis(2-hydroxyethyl) terephthalate (BHET) prepared by glycolysis of PET. TiO2-supported ruthenium catalysts produced deoxygenated compounds that included aromatic and cyclohexyl molecules. A hydrogen-pressure-dependent deoxygenation pathway was inferred from the detected intermediates. With iron added to Ru/TiO2 (Ru/Fe/TiO2), the carbon yield to C6-C8 deoxygenated compounds reached 61.1%. Proximity of Ru to Fe oxides depleted the electron density of Ru, adjusted its catalytic activity, and suppressed excessive hydrocracking, which preserved high yields of C6-C7 hydrocarbons.