Glycerol carbonate,an important glycerol value-added product,has been widely used as an active intermediate and inert solvent in the synthesis of cosmetics,detergents,chemical intermediates,polymers,and so on.The dire...Glycerol carbonate,an important glycerol value-added product,has been widely used as an active intermediate and inert solvent in the synthesis of cosmetics,detergents,chemical intermediates,polymers,and so on.The direct carbonylation from glycerol with CO_(2)is considered a promising route,but still tough work due to the thermodynamic stability and the kinetic inertness of CO_(2).In this work,highlyselective direct carbonylation of glycerol and CO_(2)into glycerol carbonate has been achieved over highly dispersed MgInCe-mixed metal oxides(MgInCe-MMO),which were prepared through the topological transformation derived from the MgInCe-layered double hydroxides(MgInCe-LDHs).By precisely modulating the surface basic-acidic properties and the oxygen vacancies,an efficient carbonylation of glycerol with CO_(2)has been achieved with a selectivity of up to>99%to glycerol carbonate.Deep investigation into the synergistic catalysis of base-acid sites and oxygen vacancies has been clarified.展开更多
L-theanine has been shown to have a therapeutic effect on depression.However,whether L-theanine has an excellent preventive effect on depression in children and adolescents and what its mechanism is have not been well...L-theanine has been shown to have a therapeutic effect on depression.However,whether L-theanine has an excellent preventive effect on depression in children and adolescents and what its mechanism is have not been well explained.Given the complexity of the pathogenesis of depression,this study investigated the preventive effect and mechanism of L-theanine on depression in juvenile rats by combining serum and hippocampal metabolomic strategies.Behavioral tests,hippocampal tissue sections,and serum and hippocampal biochemical indexes were studied,and the results confirmed the preventive effect of Ltheanine.Untargeted reversed-phase liquid chromatography-quadrupole-time-of-flight mass spectrometry and targeted hydrophilic interaction liquid chromatography-triple quadrupole mass spectrometry were developed to analyze the metabolism changes in the serum and hippocampus to screen for potential biomarkers related to L-theanine treatment.The results suggested that 28 abnormal metabolites in the serum and hippocampus that were considered as potential biomarkers returned to nearnormal levels after L-theanine administration.These biomarkers were involved in various metabolic pathways,mainly including amino acid metabolism and lipid metabolism.The levels of amino acids and neurotransmitters in the phenylalanine,tryptophan,and glutamic acid pathways were significantly reduced after L-theanine administration compared with chronic unpredictable mild stress-induced rats.In summary,L-theanine had a significant preventive effect on depression and achieved its preventive results on depression by regulating various aspects of the body,such as amino acids,lipids,and inflammation.This research systematically analyzed the mechanism of L-theanine in preventing depression and laid the foundation for applying L-theanine to prevent depression in children and adolescents.展开更多
The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenati...The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenation of alcohol to acetaldehyde requires high temperature to activate oxygen to realize the C-H cleavage,while the acetalization of acetaldehyde with ethanol is exothermic reversible reaction favorable at low temperature.The mismatching of the reaction condition for the two consecutive steps makes it a great challenge to achieve both high ethanol conversion and high DEE selectivity.This work reports a highly efficient bi-functional catalysis by Bi/BiCeO_(x)for one-pot oxidative dehydrogenation-acetalization route from ethanol to DEE under 150℃and ambient pressure,affording a selectivity of 98.5%±0.5%to DEE at an ethanol conversion of 87.0%±1.0%.An efficient tandem catalysis has been achieved on the interfacial Bi^(δ)+-Ov-Ce^(III)sites in Bi/BiCeO_(x)established by strong metal-support interaction,in which Biδ+-Ov-sites contribute to the oxidative dehydrogenation of ethanol at mild temperature,and-Ov-CeIII sites to the subsequent acetalization between the generated acetaldehyde and ethanol.展开更多
Sorbitol is a primary platform compound in the conversion of cellulose.The conversion of sorbitol to C_(6) hydrocarbons requires a complete cleavage of C–O bonds and meanwhile the inhibition of C–C cleavage.Here,we ...Sorbitol is a primary platform compound in the conversion of cellulose.The conversion of sorbitol to C_(6) hydrocarbons requires a complete cleavage of C–O bonds and meanwhile the inhibition of C–C cleavage.Here,we demonstrated an efficient selective cleavage of C–O over C–C bond on the(221)facet of supported CoGa.A selectivity of 94%to C_(6) hydrocarbon with conversion of 97%has been achieved.The selective C–O cleavage was demonstrated by tuning the exposed facet as(221)or(110).The supported CoGa was prepared simply by reduction of Co and Ga-containing layered double hydroxides(CoZnGaAl-LDHs),the exposed facets of CoGa crystallites were controlled by tailoring the temperature-programmed rate in the reduction.By reducing CoZnGaAl-LDHs,CoGa(221)was exposed with a temperature-programmed rate of 5℃/min under the induction of ZnO lattice,while CoGa(110)was exposed with a rate of 10℃/min.展开更多
Supported NiCu bimetallic catalysts have been produced in-situ on commercial Al_(2)O_(3)by using layered double hydroxides as precursors. The resulting catalysts show a uniform Ni and Cu distribution, thus providing g...Supported NiCu bimetallic catalysts have been produced in-situ on commercial Al_(2)O_(3)by using layered double hydroxides as precursors. The resulting catalysts show a uniform Ni and Cu distribution, thus providing good activity and selectivity in the reforming reaction of n-heptane. The catalytic performance has been found to depend on the Cu/Ni ratio, revealing the synergic catalysis between homogeneously dispersed Ni and Cu sites. The good catalysis of Ni Cu bimetallic catalysts makes it possible to partly or even completely replace Pt with NiCu bimetallic catalysts.展开更多
基金Financial support from the National Key Research and Development Program of China(2022YFB3805602)the National Natural Science Foundation of China(22138001,22288102)the Fundamental Research Funds for the Central Universities。
文摘Glycerol carbonate,an important glycerol value-added product,has been widely used as an active intermediate and inert solvent in the synthesis of cosmetics,detergents,chemical intermediates,polymers,and so on.The direct carbonylation from glycerol with CO_(2)is considered a promising route,but still tough work due to the thermodynamic stability and the kinetic inertness of CO_(2).In this work,highlyselective direct carbonylation of glycerol and CO_(2)into glycerol carbonate has been achieved over highly dispersed MgInCe-mixed metal oxides(MgInCe-MMO),which were prepared through the topological transformation derived from the MgInCe-layered double hydroxides(MgInCe-LDHs).By precisely modulating the surface basic-acidic properties and the oxygen vacancies,an efficient carbonylation of glycerol with CO_(2)has been achieved with a selectivity of up to>99%to glycerol carbonate.Deep investigation into the synergistic catalysis of base-acid sites and oxygen vacancies has been clarified.
文摘L-theanine has been shown to have a therapeutic effect on depression.However,whether L-theanine has an excellent preventive effect on depression in children and adolescents and what its mechanism is have not been well explained.Given the complexity of the pathogenesis of depression,this study investigated the preventive effect and mechanism of L-theanine on depression in juvenile rats by combining serum and hippocampal metabolomic strategies.Behavioral tests,hippocampal tissue sections,and serum and hippocampal biochemical indexes were studied,and the results confirmed the preventive effect of Ltheanine.Untargeted reversed-phase liquid chromatography-quadrupole-time-of-flight mass spectrometry and targeted hydrophilic interaction liquid chromatography-triple quadrupole mass spectrometry were developed to analyze the metabolism changes in the serum and hippocampus to screen for potential biomarkers related to L-theanine treatment.The results suggested that 28 abnormal metabolites in the serum and hippocampus that were considered as potential biomarkers returned to nearnormal levels after L-theanine administration.These biomarkers were involved in various metabolic pathways,mainly including amino acid metabolism and lipid metabolism.The levels of amino acids and neurotransmitters in the phenylalanine,tryptophan,and glutamic acid pathways were significantly reduced after L-theanine administration compared with chronic unpredictable mild stress-induced rats.In summary,L-theanine had a significant preventive effect on depression and achieved its preventive results on depression by regulating various aspects of the body,such as amino acids,lipids,and inflammation.This research systematically analyzed the mechanism of L-theanine in preventing depression and laid the foundation for applying L-theanine to prevent depression in children and adolescents.
基金support from the National Natural Science Foundation of China(Nos.22138001 and 21521005)the National Key R&D Program of China(No.2017YFA0206804)is acknowledged.
文摘The direct conversion of ethanol to 1,1-diethoxyethane(DEE)through one-pot dehydrogenation-acetalization has attracted broad interest from both academia and industry.Based on thermodynamics,the oxidative dehydrogenation of alcohol to acetaldehyde requires high temperature to activate oxygen to realize the C-H cleavage,while the acetalization of acetaldehyde with ethanol is exothermic reversible reaction favorable at low temperature.The mismatching of the reaction condition for the two consecutive steps makes it a great challenge to achieve both high ethanol conversion and high DEE selectivity.This work reports a highly efficient bi-functional catalysis by Bi/BiCeO_(x)for one-pot oxidative dehydrogenation-acetalization route from ethanol to DEE under 150℃and ambient pressure,affording a selectivity of 98.5%±0.5%to DEE at an ethanol conversion of 87.0%±1.0%.An efficient tandem catalysis has been achieved on the interfacial Bi^(δ)+-Ov-Ce^(III)sites in Bi/BiCeO_(x)established by strong metal-support interaction,in which Biδ+-Ov-sites contribute to the oxidative dehydrogenation of ethanol at mild temperature,and-Ov-CeIII sites to the subsequent acetalization between the generated acetaldehyde and ethanol.
基金the National Natural Science Foundation of China(No.22108009)the National Key R&D Program of China(No.2017YFA0206804)are gratefully acknowledged..
文摘Sorbitol is a primary platform compound in the conversion of cellulose.The conversion of sorbitol to C_(6) hydrocarbons requires a complete cleavage of C–O bonds and meanwhile the inhibition of C–C cleavage.Here,we demonstrated an efficient selective cleavage of C–O over C–C bond on the(221)facet of supported CoGa.A selectivity of 94%to C_(6) hydrocarbon with conversion of 97%has been achieved.The selective C–O cleavage was demonstrated by tuning the exposed facet as(221)or(110).The supported CoGa was prepared simply by reduction of Co and Ga-containing layered double hydroxides(CoZnGaAl-LDHs),the exposed facets of CoGa crystallites were controlled by tailoring the temperature-programmed rate in the reduction.By reducing CoZnGaAl-LDHs,CoGa(221)was exposed with a temperature-programmed rate of 5℃/min under the induction of ZnO lattice,while CoGa(110)was exposed with a rate of 10℃/min.
基金Financial supports from National Nature Science Foundation of China (NSFC, Nos. 91634120 and 21521005)the National Key Research and Development Program of China (No. 2017YFA0206804)the Fundamental Research Funds for the Central Universities(No. XK1802-6)。
文摘Supported NiCu bimetallic catalysts have been produced in-situ on commercial Al_(2)O_(3)by using layered double hydroxides as precursors. The resulting catalysts show a uniform Ni and Cu distribution, thus providing good activity and selectivity in the reforming reaction of n-heptane. The catalytic performance has been found to depend on the Cu/Ni ratio, revealing the synergic catalysis between homogeneously dispersed Ni and Cu sites. The good catalysis of Ni Cu bimetallic catalysts makes it possible to partly or even completely replace Pt with NiCu bimetallic catalysts.