Photocatalytic Cleavage of β-O-4 Ether Bonds in Lignin over Ni/TiO2

Molecules

Minghao Zhou¹  Peng Liu¹  BrajendraK. Sharma¹  Jiaping Zhao²  Changzhou Chen²  Haihong Xia²  Jianchun Jiang² 

[1] Key and Open Lab. on Forest Chemical Engineering, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, SFA, Nanjing 210042, China;Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Lab. for Biomass Chemical Utilization;

关键词: lignin;    β-O-4;    photocatalyst;    Ni/TiO₂;    oxidant PCC;   

DOI  :  10.3390/molecules25092109

来源: DOAJ

【 摘 要 】

It is of great importance to explore the selective hydrogenolysis of β-O-4 linkages, which account for 45–60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO₂ exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO₂ and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of β-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO₂ photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of β-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of β-O-4 alcohol to β-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained β-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing β-O-4 linkage for the generation of fragmentation products in good to excellent results.

【 授权许可】

Unknown