摘要
This study demonstrates the direct hydrogenation of polyethylene terephthalate (PET) dissolved in 1,1,1,3,3,3-hexafluro-2-propanol to environmentally friendly polyester polyethylene-1,4-cyclohexanedicarboxylate (PECHD) using a Vulcan XC-72 supported Rh-Pt bimetallic catalyst synthesized via a polyol method. The hydrogenation of PET was promoted by RhOx species present on the catalyst support surface which was generated using the polyol synthesis method. As compared to the monometallic Rh catalyst, the Rh-Pt bimetallic catalyst was found to be superior for hydrogenation of PET. This superiority was attributed to the strong aromatic ring adsorption ability of Rh working in synergy with an increased H2 spillover by Pt. At a H2 pressure of 6.89 MPa and 50 °C for 60 min, complete hydrogenation of PET to PECHD was achieved over the Rh-Pt bimetallic catalyst possessing theoretical Rh and Pt metal loadings of 2.5 wt% each. PECHD was found to be recovered to a very high extent using the compressed CO2 anti-solvent technique after hydrogenation of PET. © 2020 Elsevier B.V.