title: Synergy in Lignin Upgrading by a Combination of Cu-Based Mixed Oxide and Ni-Phosphide Catalysts in Supercritical Ethanol.
abstract: The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu-Mg-Al oxide (CuMgAlOx) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO2, Ni2P/SiO2, and Ni/ASA (ASA = amorphous silica alumina), with the aim of combining lignin depolymerization and HDO in a single reaction step. While the silica-supported catalysts were themselves hardly active in lignin upgrading, Ni/ASA displayed comparable lignin monomer yield as CuMgAlOx. A drawback of using an acidic support is extensive dehydration of the ethanol solvent. Instead, combining CuMgAlOxwith Ni/SiO2and especially Ni2P/SiO2proved to be effective in increasing the lignin monomer yield, while at the same time reducing the oxygen content of the products. With Ni2P/SiO2, the lignin monomer yield was 53 wt %, leading to nearly complete deoxygenation of the aromatic products.
authors.affiliation: Schuit Institute of Catalysis, Inorganic Materials Chemistry, Eindhoven University of Technology , Den Dolech 2, 5612 AZ, Eindhoven, The Netherlands.
authors.forename: Tamás I
authors.initials: TI
authors.lastname: Korányi
authors.affiliation: Schuit Institute of Catalysis, Inorganic Materials Chemistry, Eindhoven University of Technology , Den Dolech 2, 5612 AZ, Eindhoven, The Netherlands.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Huang
authors.affiliation: Schuit Institute of Catalysis, Inorganic Materials Chemistry, Eindhoven University of Technology , Den Dolech 2, 5612 AZ, Eindhoven, The Netherlands.
authors.forename: Alessandro E
authors.initials: AE
authors.lastname: Coumans
authors.affiliation: Schuit Institute of Catalysis, Inorganic Materials Chemistry, Eindhoven University of Technology , Den Dolech 2, 5612 AZ, Eindhoven, The Netherlands.
authors.forename: Emiel J M
authors.initials: EJ
authors.lastname: Hensen
keywords: Aromatics; Hydrodeoxygenation; Lignin; Ni2P; Supercritical ethanol