title: Tungsten Carbide: A Remarkably Efficient Catalyst for the Selective Cleavage of Lignin C-O Bonds.
abstract: A remarkably effective method for the chemoselective cleavage of the C-O bonds of typical β-O-4 model compounds and the deconstruction of lignin feedstock was developed by using tungsten carbide as the catalyst. High yields of C-O cleavage products (up to 96.8 %) from model compounds and liquid oils (up to 70.7 %) from lignin feedstock were obtained under low hydrogen pressure (0.69 MPa) in methanol. The conversion efficiency was determined to a large extent by solvent effects and was also affected by both the electronic and steric effects of the lignin model compounds. In situ W2C/activated carbon (AC)-catalyzed hydrogen transfer from methanol to the substrate was proposed to be responsible for the high performance in methanol solvent. The conversion of 2-(2-methoxyphenoxy)-1-phenylethanol showed that the catalyst could be reused five times without a significant loss in activity for C-O bond cleavage, whereas the selectivity to value-added styrene increased markedly owing to partial oxidation of the W2C phase according to X-ray diffraction, Raman spectroscopy, and transmission electron microscopy characterization. 2 D-HSQC-NMR spectroscopy analysis showed that W2C/AC exhibited high activity not only for β-O-4 cleavage but also for the deconstruction of more resistant α-O-4 and β-β linkages, so that a high yield of liquid oil was obtained from lignin. Corn stalk lignin was more liable to be depolymerized than birch lignin owing to its loosened structure (scanning electron microscopy results), larger surface area (BET results), and lower molecular weight (gel-permeation chromatography results), whereas its liquid oil composition was more complicated than that of birch wood lignin in that the former lignin contained more p-hydroxyphenyl units and the former contained noncanonical units.
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors: Haiwei
authors: H
authors: Guo
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
authors: Bo
authors: B
authors: Zhang
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
authors: Changzhi
authors: C
authors: Li
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors: Chang
authors: C
authors: Peng
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors: Tao
authors: T
authors: Dai
authors: Department of Polymeric Materials & Engineering, College of Materials & Metallurgy, Guizhou University, Guiyang, 550025, China.
authors: Haibo
authors: H
authors: Xie
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
authors: Aiqin
authors: A
authors: Wang
authors: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
authors: Tao
authors: T
authors: Zhang
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D008031:Lignin / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D017973:Tungsten Compounds; C002802:tungsten carbide; D002244:Carbon; D008031:Lignin; D010100:Oxygen
keywords: aromatics; biomass; lignin; methanol; tungsten