Considering energy shortage, large molecules in corn cob and easy separation of solid catalysts, nano oxides are used to transform corn cob into useful chemicals. Because of the microcrystals, nano oxides offer enough...Considering energy shortage, large molecules in corn cob and easy separation of solid catalysts, nano oxides are used to transform corn cob into useful chemicals. Because of the microcrystals, nano oxides offer enough accessible sites for cellulose, hemicellulose and monosaccharide from corn cob hydrolysis and oxidant. Chemical conversion of corn cob to organic acids is investigated over nano ceria, alumina, titania and zirconia under various atmospheres. Liquid products are mainly formic and acetic acids. A small amount of other compounds, such as D-xylose,D-glucose, arabinose and xylitol are also detected simultaneously. The yield of organic acids reaches 25%–29% over the nano oxide of ceria,zirconia and alumina with 3 h reaction time under 453 K and 1.2 MPa O2. The unique and fast conversion of corn cob is directly approached over the nano oxides. The results are comparative to those of biofermentation and offer an alternative method in chemically catalytic conversion of corn cob to useful chemicals in a one-pot chemical process.展开更多
To study the effect of adjacent hydroxyl to the active sites, several acid catalysts, i.e. substituted benzoic acids with adjacent carboxyl are employed in the fructose dehydration to 5-hydroxymethylfurfural(HMF).Expe...To study the effect of adjacent hydroxyl to the active sites, several acid catalysts, i.e. substituted benzoic acids with adjacent carboxyl are employed in the fructose dehydration to 5-hydroxymethylfurfural(HMF).Experimental results reveal that Br?nsted acid sites with adjacent carboxyl present higher catalytic ability than isolated ones. Computational results suggest that the adjacent sites lead to co-interaction on fructose, corresponding more stable transition state and faster HMF formation rate. Based on the enhancement from the adjacent sites, a novel ordered mesoporous carbon(OMC) full of carboxyls in surface is prepared and turns out to be an effective solid catalyst for HMF production from fructose derived from biomass.展开更多
Atomically precise water-soluble gold nanoclusters(Au NCs)protected by organic ligands have attracted growing attention in serving as unique nanomaterials with the potential to generate theranostic tools(bioimaging,bi...Atomically precise water-soluble gold nanoclusters(Au NCs)protected by organic ligands have attracted growing attention in serving as unique nanomaterials with the potential to generate theranostic tools(bioimaging,biosensing,and biotherapy),due to their ultrasmall size,superior photoluminescence,good biocompatibility,and nontoxicity.More importantly,Au NCs afford a well-defined atomic packing structure and molecular purity,providing a superior platform to unravel the structure−performance correlations for biodistribution,biological pharmacokinetics,and excretion of Au NCs.In this Review,we mainly survey the synthesis of water-soluble Au NCs and the recent progress in biomedicine of Au NCs,including bioimaging,biosensing,and biotherapy.The effects of ligand and size on the biomedical properties are discussed in detail.We hope that the advances in this research area can expand the applications of Au NCs in biomedicine.展开更多
基金supported by the National Natural Science Foundation of China(91434101,91745108)the Ministry of Science and Technology of the People’s Republic of China(2017YFB0702900)~~
基金supported by the Doctoral Fund of the Ministry of Education of China(Grant No.20100091120035)NSF of China(21103087)
文摘Considering energy shortage, large molecules in corn cob and easy separation of solid catalysts, nano oxides are used to transform corn cob into useful chemicals. Because of the microcrystals, nano oxides offer enough accessible sites for cellulose, hemicellulose and monosaccharide from corn cob hydrolysis and oxidant. Chemical conversion of corn cob to organic acids is investigated over nano ceria, alumina, titania and zirconia under various atmospheres. Liquid products are mainly formic and acetic acids. A small amount of other compounds, such as D-xylose,D-glucose, arabinose and xylitol are also detected simultaneously. The yield of organic acids reaches 25%–29% over the nano oxide of ceria,zirconia and alumina with 3 h reaction time under 453 K and 1.2 MPa O2. The unique and fast conversion of corn cob is directly approached over the nano oxides. The results are comparative to those of biofermentation and offer an alternative method in chemically catalytic conversion of corn cob to useful chemicals in a one-pot chemical process.
基金supported by the Natural Science Foundation of Jiangsu Province (BK20151380)NSF of China (21103087 and 21872067)supported by the Fundamental Research Funds for the Central Universities (020514380116)。
文摘To study the effect of adjacent hydroxyl to the active sites, several acid catalysts, i.e. substituted benzoic acids with adjacent carboxyl are employed in the fructose dehydration to 5-hydroxymethylfurfural(HMF).Experimental results reveal that Br?nsted acid sites with adjacent carboxyl present higher catalytic ability than isolated ones. Computational results suggest that the adjacent sites lead to co-interaction on fructose, corresponding more stable transition state and faster HMF formation rate. Based on the enhancement from the adjacent sites, a novel ordered mesoporous carbon(OMC) full of carboxyls in surface is prepared and turns out to be an effective solid catalyst for HMF production from fructose derived from biomass.
基金financial support from the Foundation of the Jiangsu Higher Education Institutions of China(22KJB150026)the National Natural Science Foundation of China(22178161,22101128).
文摘Atomically precise water-soluble gold nanoclusters(Au NCs)protected by organic ligands have attracted growing attention in serving as unique nanomaterials with the potential to generate theranostic tools(bioimaging,biosensing,and biotherapy),due to their ultrasmall size,superior photoluminescence,good biocompatibility,and nontoxicity.More importantly,Au NCs afford a well-defined atomic packing structure and molecular purity,providing a superior platform to unravel the structure−performance correlations for biodistribution,biological pharmacokinetics,and excretion of Au NCs.In this Review,we mainly survey the synthesis of water-soluble Au NCs and the recent progress in biomedicine of Au NCs,including bioimaging,biosensing,and biotherapy.The effects of ligand and size on the biomedical properties are discussed in detail.We hope that the advances in this research area can expand the applications of Au NCs in biomedicine.
