Switchable production of aromatics and alkanes by Ni-ReOx/CeO2-catalyzed wood depolymerization

Abstract

Complete conversion of lignocellulosic biomass into chemicals and fuels is particularly attractive in biorefinery concept while remains a great challenge due to complicated structure of lignocellulose and its notorious resistance to chemical transformation. Herein, a recyclable multifunctional Ni-ReOx/CeO2 catalyst was designed for switchable conversion of lignocellulose to either aromatics or liquid fuels by simple tuning reaction parameters. Under the condition of 200 °C, 1 MPa H2, lignin in woody biomass was deconstructed via lignin-first manner to produce aromatic oil with the mass yield up to 88.4 %, leaving cellulose and hemicellulose intact. Under harsher condition (260 °C, 4 MPa H2), complete conversion of lignocellulose to alkanes was achieved in 43.8 % carbon yield. The control experiments and characterization of the catalyst revealed that ReOx species of Ni-ReOx/CeO2 enhanced Ni dispersion, the strong electronic interaction and synergic effects of Ni and ReOx species played major roles for the flexible transformation.