Open AccessSynergy in Lignin Upgrading by a Combination of Cu-Based Mixed Oxide and Ni-Phosphide Catalysts in Supercritical Ethanol
Author(s) -
TI Tamás Korányi,
Xiaoming Huang,
AE Alessandro Coumans,
Emiel J. M. Hensen
Publication year - 2017
Publication title -
acs sustainable chemistry and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.878
H-Index - 109
ISSN - 2168-0485
DOI - 10.1021/acssuschemeng.7b00239
Subject(s) - depolymerization , hydrodeoxygenation , lignin , catalysis , deoxygenation , phosphide , chemistry , supercritical fluid , yield (engineering) , monomer , organic chemistry , ethanol , materials science , polymer , selectivity , metallurgy
The depolymerization of lignin to bioaromatics usually requires a hydrodeoxygenation (HDO) step to lower the oxygen content. A mixed Cu-Mg-Al oxide (CuMgAlO x ) is an effective catalyst for the depolymerization of lignin in supercritical ethanol. We explored the use of Ni-based cocatalysts, i.e. Ni/SiO 2 , Ni 2 P/SiO 2 , 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 CuMgAlO x . A drawback of using an acidic support is extensive dehydration of the ethanol solvent. Instead, combining CuMgAlO x with Ni/SiO 2 and especially Ni 2 P/SiO 2 proved to be effective in increasing the lignin monomer yield, while at the same time reducing the oxygen content of the products. With Ni 2 P/SiO 2 , the lignin monomer yield was 53 wt %, leading to nearly complete deoxygenation of the aromatic products.