A promising catalyst, KNaY was prepared by an ion exchange method with aqueous potassium chloride solution, Compared with NaY, KNaY was an effective catalyst for the dehydration of methyl lactate to methyl acrylate. U...A promising catalyst, KNaY was prepared by an ion exchange method with aqueous potassium chloride solution, Compared with NaY, KNaY was an effective catalyst for the dehydration of methyl lactate to methyl acrylate. Under the optimized conditions, an improved yield of 37.9 mol% was achieved.展开更多
Designing a catalytic system that could convert cellulose to switchable C3 alcohols or esters with controllable selectivity is highly desired to meet the rapidly changing market demand.Herein,we develop RuSn catalysts...Designing a catalytic system that could convert cellulose to switchable C3 alcohols or esters with controllable selectivity is highly desired to meet the rapidly changing market demand.Herein,we develop RuSn catalysts with the altering Sn loadings that can achieve acetol formation from cellulose hydrogenation at240℃in presence of H_(2)or yield methyl lactate production from cellulose conversion in methanol and water mixture at 200℃in presence of N_(2).The increased Sn contents from 3%to 6%lead to form different surface sites from Ru_(3)Sn_(7),Ru,and SnO_(x)to Ru_(3)Sn_(7)and SnO_(x).The integrated Ru_(3)Sn_(7),Ru,and SnO_(x)species on 1.5%Ru-3%Sn/SiO_(2)catalyze isomerization,retro-aldol condensation,and hydrogenation individual steps with coordinated reaction rates,resulting in the acetol formation with a high yield of 53.7 C%.Furthermore,the optimum combination of Ru_(3)Sn_(7)and SnO_(x)on 1.5%Ru-6%Sn/SiO_(2)contributes to the isomerization,retro-aldol condensation,dehydration,and 1,2-hydride shift,giving rise to the preferential production of methyl lactate at a 25.1 C%yield.These results illustrate the feasibility of controlling the selective conversion of cellulose to C3 acetol or methyl lactate by devising a tunable catalytic system,which guides the rational design of catalysts for the selective conversion of cellulose.展开更多
Cellulosic sugars derived from lignocellulose are the most abundant and inexpensive raw materials used for the production of methyl lactate(MLA).In this study,hierarchical Sn-MFI zeolite with intracrystalline mesoporo...Cellulosic sugars derived from lignocellulose are the most abundant and inexpensive raw materials used for the production of methyl lactate(MLA).In this study,hierarchical Sn-MFI zeolite with intracrystalline mesoporosity was developed,capable of catalyzing the one-pot conversion of cellulosic sugars into MLA in a CH_(3)OH/H_(2)O mixture.The MLA yield from glucose using the hierarchical Sn-MFI zeolite was almost twice as high as that using the conventional microporous Sn-MFI zeolite.This superior catalytic performance was attributed to the reduced diffusion limitation of glucose within the hierarchical Sn-MFI catalyst,which possessed significant intercrystalline mesoporosity.Additionally,the hierarchical Sn-MFI catalyst was recycled for five reaction runs of the one-pot conversion of glucose without an obvious loss of activity,indicating excellent stability and reusability and broadening the scope of carbohydrates used to obtain MLA.展开更多
文摘A promising catalyst, KNaY was prepared by an ion exchange method with aqueous potassium chloride solution, Compared with NaY, KNaY was an effective catalyst for the dehydration of methyl lactate to methyl acrylate. Under the optimized conditions, an improved yield of 37.9 mol% was achieved.
基金supported by“the Research Funds of Happiness Flower ECNU”(2019ST2101)。
文摘Designing a catalytic system that could convert cellulose to switchable C3 alcohols or esters with controllable selectivity is highly desired to meet the rapidly changing market demand.Herein,we develop RuSn catalysts with the altering Sn loadings that can achieve acetol formation from cellulose hydrogenation at240℃in presence of H_(2)or yield methyl lactate production from cellulose conversion in methanol and water mixture at 200℃in presence of N_(2).The increased Sn contents from 3%to 6%lead to form different surface sites from Ru_(3)Sn_(7),Ru,and SnO_(x)to Ru_(3)Sn_(7)and SnO_(x).The integrated Ru_(3)Sn_(7),Ru,and SnO_(x)species on 1.5%Ru-3%Sn/SiO_(2)catalyze isomerization,retro-aldol condensation,and hydrogenation individual steps with coordinated reaction rates,resulting in the acetol formation with a high yield of 53.7 C%.Furthermore,the optimum combination of Ru_(3)Sn_(7)and SnO_(x)on 1.5%Ru-6%Sn/SiO_(2)contributes to the isomerization,retro-aldol condensation,dehydration,and 1,2-hydride shift,giving rise to the preferential production of methyl lactate at a 25.1 C%yield.These results illustrate the feasibility of controlling the selective conversion of cellulose to C3 acetol or methyl lactate by devising a tunable catalytic system,which guides the rational design of catalysts for the selective conversion of cellulose.
基金supported by the National Natural Science Foundation of China[22272166]Department of Science&Technology of Liaoning Province[2023JH2/101800050]Dalian Institute of Chemical Physics[DICP I202116 and DICP I202214].
文摘Cellulosic sugars derived from lignocellulose are the most abundant and inexpensive raw materials used for the production of methyl lactate(MLA).In this study,hierarchical Sn-MFI zeolite with intracrystalline mesoporosity was developed,capable of catalyzing the one-pot conversion of cellulosic sugars into MLA in a CH_(3)OH/H_(2)O mixture.The MLA yield from glucose using the hierarchical Sn-MFI zeolite was almost twice as high as that using the conventional microporous Sn-MFI zeolite.This superior catalytic performance was attributed to the reduced diffusion limitation of glucose within the hierarchical Sn-MFI catalyst,which possessed significant intercrystalline mesoporosity.Additionally,the hierarchical Sn-MFI catalyst was recycled for five reaction runs of the one-pot conversion of glucose without an obvious loss of activity,indicating excellent stability and reusability and broadening the scope of carbohydrates used to obtain MLA.
