The production of?-valerolactone(GVL)from lignocellulosic biomass has become a focus of research owing to its potential applications in fuels and chemicals.In this study,(n)CuOx-CaCO3(where n is the molar ratio of Cu ...The production of?-valerolactone(GVL)from lignocellulosic biomass has become a focus of research owing to its potential applications in fuels and chemicals.In this study,(n)CuOx-CaCO3(where n is the molar ratio of Cu to Ca)compounds were prepared for the first time and shown to function as efficient bifunctional catalysts for the conversion of biomass-derived methyl levulinate(ML)into GVL,using methanol as the in-situ hydrogen source.Among the catalysts with varied Cu/Ca molar ratios,(3/2)CuOx-CaCO3 provided the highest GVL yield of 95.6% from ML.The incorporation of CaCO3 with CuO resulted in the formation of Cu+species in a CuOx-CaCO3 catalyst,which greatly facilitated the hydrogenation of ML.Notably,CuOx-CaCO3 also displayed excellent catalytic performance in the methanolysis products of cellulose,even in the presence of humins.Therefore,a facile two-step strategy for the production of GVL from cellulose could be developed over this robust and inexpensive catalyst,through the integration of cellulose methanolysis catalyzed by sulfuric acid,methanol reforming,and ML hydrogenation in methanol medium.展开更多
Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ c...Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ controllable synthesize heterogeneous bimetallic Ni3Fe NPs@C nanocatalyst.The X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy and N2 adsorption‐description results reveal that the Ni3Fe alloy nanoparticles are evenly embedded in carbon matrix.The as‐prepared Ni3Fe NPs@C catalyst shows excellent selective hydrogenation catalytic performance toward the conversion of levulinic acid(LA)toγ‐valerolactone(GVL)via both direct hydrogenation(DH)and transfer hydrogenation(TH).In DH of LA,the bimetallic catalyst achieved a 93.8%LA conversion efficiency with a 95.5%GVL selectivity and 38.2 mmol g–1 h–1 GVL productivity(under 130°C,2MPa H2 within 2 h),which are 6 and 40 times in comparison with monometallic Ni NPs@C and Fe NPs@C catalysts,respectively.In addition,the identical catalyst displayed a full conversion of LA with almost 100%GVL selectivity and 167.1 mmol g–1 h–1 GVL productivity at 180°C within 0.5 h in TH of LA.Under optimal reaction conditions,the DH and TH catalytic performance of 500‐Ni3Fe NPs@C(3:1)catalyst for converting LA to GVL is comparable to the state‐of‐the‐art noble‐based catalysts.The demonstrated capability of bimetallic catalyst design approach to introduce dual‐catalytic functionality for DH and TH reactions could be adoptable for other catalysis processes.展开更多
基金supported by the National Natural Science Foundation of China(21676223,21706223,21776234,21606188)the Fundamental Research Funds for the Central Universities(20720180084),the Energy development Foundation of Energy College,Xiamen University(2017NYFZ02)+1 种基金the Natural Science Foundation of Fujian Province of China(2018J01017)the Education Department of Fujian Province(JZ160398)~~
文摘The production of?-valerolactone(GVL)from lignocellulosic biomass has become a focus of research owing to its potential applications in fuels and chemicals.In this study,(n)CuOx-CaCO3(where n is the molar ratio of Cu to Ca)compounds were prepared for the first time and shown to function as efficient bifunctional catalysts for the conversion of biomass-derived methyl levulinate(ML)into GVL,using methanol as the in-situ hydrogen source.Among the catalysts with varied Cu/Ca molar ratios,(3/2)CuOx-CaCO3 provided the highest GVL yield of 95.6% from ML.The incorporation of CaCO3 with CuO resulted in the formation of Cu+species in a CuOx-CaCO3 catalyst,which greatly facilitated the hydrogenation of ML.Notably,CuOx-CaCO3 also displayed excellent catalytic performance in the methanolysis products of cellulose,even in the presence of humins.Therefore,a facile two-step strategy for the production of GVL from cellulose could be developed over this robust and inexpensive catalyst,through the integration of cellulose methanolysis catalyzed by sulfuric acid,methanol reforming,and ML hydrogenation in methanol medium.
文摘Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ controllable synthesize heterogeneous bimetallic Ni3Fe NPs@C nanocatalyst.The X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy and N2 adsorption‐description results reveal that the Ni3Fe alloy nanoparticles are evenly embedded in carbon matrix.The as‐prepared Ni3Fe NPs@C catalyst shows excellent selective hydrogenation catalytic performance toward the conversion of levulinic acid(LA)toγ‐valerolactone(GVL)via both direct hydrogenation(DH)and transfer hydrogenation(TH).In DH of LA,the bimetallic catalyst achieved a 93.8%LA conversion efficiency with a 95.5%GVL selectivity and 38.2 mmol g–1 h–1 GVL productivity(under 130°C,2MPa H2 within 2 h),which are 6 and 40 times in comparison with monometallic Ni NPs@C and Fe NPs@C catalysts,respectively.In addition,the identical catalyst displayed a full conversion of LA with almost 100%GVL selectivity and 167.1 mmol g–1 h–1 GVL productivity at 180°C within 0.5 h in TH of LA.Under optimal reaction conditions,the DH and TH catalytic performance of 500‐Ni3Fe NPs@C(3:1)catalyst for converting LA to GVL is comparable to the state‐of‐the‐art noble‐based catalysts.The demonstrated capability of bimetallic catalyst design approach to introduce dual‐catalytic functionality for DH and TH reactions could be adoptable for other catalysis processes.
