Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for ...Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides, such as Bi2O3, Sb2O3, SnO2, TiO2, Nb2O5 and Sb2O5, was investigated. It was found that in the six investigated metal oxides, only Sb205 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%, and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and 12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine, which indicated that in the six investigated metal oxides, only Sb2O5 possessed Bronsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Bronsted acid sites of Sb2O5. Reusability tests showed that with 5b205 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed.展开更多
Core-shell magnetic polymer microspheres with mesoporous organic shells hold immense potential in diverse applications,encompassing adsorption,separation,delivery/immobilization of vip molecules in catalysis and con...Core-shell magnetic polymer microspheres with mesoporous organic shells hold immense potential in diverse applications,encompassing adsorption,separation,delivery/immobilization of vip molecules in catalysis and controlled drug release.Herein,magnetic mesoporous melamine-formaldehyde resin microspheres(Fe_(3)O_(4)@SiO_(2)@mMF)are constructed via a nanoemulsion-assisted interfacial co-assembly and polymerization strategy,using Pluronic F127 as a template agent and soluble melamine-formaldehyde(MF)oligomer as the precursor.The resulting microspheres possess radially oriented mesopores,superparamagnetic properties,and abundant N-containing active sites(nitrogen content:15.02 wt%).The assynthesized Fe_(3)O_(4)@SiO_(2)@mMF microspheres as ideal catalyst supports,exhibit exceptional loading capacity for phosphotungstic acid(PTA).The as-formed Fe_(3)O_(4)@SiO_(2)@mMF/PTA composites demonstrate not only good catalytic performance in the esterification reaction of n-butanol and acetic acid with a high conversion of 92%(to acetic acid)but also excellent antimicrobial performance against Staphylococcus aureus and Escherichia coli with viabilities of 11.58%and 7.35%,respectively.展开更多
基金supported by the"Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues"of the Chinese Academy of Sciences(XDA050102)the National Natural Science Foundation of China(21233008)
文摘Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides, such as Bi2O3, Sb2O3, SnO2, TiO2, Nb2O5 and Sb2O5, was investigated. It was found that in the six investigated metal oxides, only Sb205 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%, and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and 12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine, which indicated that in the six investigated metal oxides, only Sb2O5 possessed Bronsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Bronsted acid sites of Sb2O5. Reusability tests showed that with 5b205 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed.
基金financially supported by National Key R&D Program of China(No.2024YFD2402203)National Natural Science Foundation of China(Nos.22125501,U22A20152)Science and Technology Commission of Shanghai Municipality(No.2024ZDSYS02)。
文摘Core-shell magnetic polymer microspheres with mesoporous organic shells hold immense potential in diverse applications,encompassing adsorption,separation,delivery/immobilization of vip molecules in catalysis and controlled drug release.Herein,magnetic mesoporous melamine-formaldehyde resin microspheres(Fe_(3)O_(4)@SiO_(2)@mMF)are constructed via a nanoemulsion-assisted interfacial co-assembly and polymerization strategy,using Pluronic F127 as a template agent and soluble melamine-formaldehyde(MF)oligomer as the precursor.The resulting microspheres possess radially oriented mesopores,superparamagnetic properties,and abundant N-containing active sites(nitrogen content:15.02 wt%).The assynthesized Fe_(3)O_(4)@SiO_(2)@mMF microspheres as ideal catalyst supports,exhibit exceptional loading capacity for phosphotungstic acid(PTA).The as-formed Fe_(3)O_(4)@SiO_(2)@mMF/PTA composites demonstrate not only good catalytic performance in the esterification reaction of n-butanol and acetic acid with a high conversion of 92%(to acetic acid)but also excellent antimicrobial performance against Staphylococcus aureus and Escherichia coli with viabilities of 11.58%and 7.35%,respectively.
