State Key Laboratory of Chemical Engineering (Tianjin University), Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering, Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, China.
Bioresour Technol. 2021 Mar;323:124634. doi: 10.1016/j.biortech.2020.124634. Epub 2020 Dec 31.
The efficient depolymerization and hydrodeoxygenation of enzymatic hydrolysis lignin are achieved in cyclohexane solvents over a gamma-alumina supported nickel molybdenum alloy catalyst in a single step. Under initial 3 MPa hydrogen at 320 °C, the highest overall cycloalkane yield of 104.4 mg/g enzymatic hydrolysis lignin with 44.4 wt% selectivity of ethyl-cyclohexane was obtained. The reaction atmosphere and temperature have significant effects on enzymatic hydrolysis lignin conversion, product type and distribution. The conversion of enzymatic hydrolysis lignin was also investigated over different nickel and molybdenum-based catalysts, and the gamma-alumina supported nickel molybdenum alloy catalyst exhibited the highest activity among those catalysts. To reveal the reaction pathways of alkylphenol hydrodeoxygenation, 4-ethylphenol was tested as a model compound. Complete conversion of 4-ethylphenol into cycloalkanes was achieved. A two-step mechanism of 4-ethylphenol dihydroxylation - hydrogenation is proposed, in which the benzene ring saturation is deemed as the rate-determining step.
在一步法中，在环己烷溶剂中，γ-氧化铝负载的镍钼合金催化剂可实现酶解木质素的高效解聚和加氢脱氧。在初始 3 MPa 氢气和 320°C 的条件下，酶解木质素的总环烷烃收率最高可达 104.4mg/g，乙基环己烷的选择性为 44.4wt%。反应气氛和温度对酶解木质素的转化、产物类型和分布有显著影响。还在不同的镍和钼基催化剂上考察了酶解木质素的转化，γ-氧化铝负载的镍钼合金催化剂在这些催化剂中表现出最高的活性。为了揭示烷基酚加氢脱氧的反应途径，选择了 4-乙基苯酚作为模型化合物。4-乙基苯酚完全转化为环烷烃。提出了 4-乙基苯酚二羟基化-加氢的两步机理，其中苯环饱和被认为是速率决定步骤。
