The conversion process of chitin,one of the abundant biomass resources on the earth,not only follows the principles of green chemistry,but also has significant value in industrial applications.However,it is a great ch...The conversion process of chitin,one of the abundant biomass resources on the earth,not only follows the principles of green chemistry,but also has significant value in industrial applications.However,it is a great challenge to directly convert insoluble and rigid structured chitin to 5-hydroxymethylfurfural(HMF).To address this issue,we developed a green conversion process combining pretreatment and catalytic system.Chitin was first pretreated by hexafluoro isopropanol(HFIP),which somewhat disrupted the hydrogen bonding network within the chitin structure.Subsequently,formic acid(FA)and silicotungstic acid(STA)synergistically catalyzed the conversion to HMF in a biphasic system of 2-methyltetrahydrofuran(2-Me-THF)/H2O,and high yields(40.2%)HMF was obtained under the optimism conditions.The product distribution was analyzed by HPLC-MS and the co-catalysis of FA with STA was evidenced.A dual-function catalytic system with both Lewis and Br?nsted acids was created,the catalytic system that significantly improved the efficiency of complex tandem catalytic reactions with chitin.Based on the experimental results,a possible pathway for chitin conversion was deduced,providing a new catalytic idea for the efficient conversion of chitin to HMF.展开更多
Layered V_(2)O_(5) cathode holds the merits of high theoretical specific capacity(589 mA h g^(-1))in aqueous zinc-ion batteries(AZIBs),yet it still suffers from inferior bulk conductivity and structure degradation not...Layered V_(2)O_(5) cathode holds the merits of high theoretical specific capacity(589 mA h g^(-1))in aqueous zinc-ion batteries(AZIBs),yet it still suffers from inferior bulk conductivity and structure degradation notably during prolonged cycling.Herein,we ingeniously design cations(Na^(+)/Co^(2+)/Al^(3+))and anion(F^(-))synergistic-doped hydrated V_(2)O_(5)·0.48H_(2)O cathode(VNACOF)to enhance the electronic and spatial effects in the bulk.A range of in-situ,ex-situ characterizations,and DFT calculations profoundly clarify the strengthened ionic/electronic conductivities,structural stability,and Zn^(2+)diffusion kinetics.As a result,the VNACOF displays a superior discharge capacity(529 mA h g^(-1)@0.1 C),rate capabilities(488 mA h g^(-1)@0.5 C,437 mA h g^(-1)@1C),and cycling stability(301 mA h g^(-1)@10 C@5000 cycles@93%)with sufficient energy density(393 W h kg^(-1)),Furthermore,the pouch-cells with high-load(60 mg)also deliver superior cyclic(2 C@178 mA h g^(-1)@1000 cycles@90%)and rate performance(132 mA h g^(-1)@5 C),revealing great application potential for high-energy-density and high-stability AZIBs.展开更多
基金Supported by the National Natural Science Foundation of China(No.42076126)the Shandong Key R&D Plan+2 种基金Major Scientific and Technological Innovation Project(No.2022CXGC020413)the Natural Science Foundation of Shandong Province(Nos.ZR2020MD072,ZR2021QD014)the Liaoning Provincial Natural Science Foundation:Joint Open Fund of the State Key Laboratory for the Creation and Development of New Pesticides(No.2022-KF-25-03)。
文摘The conversion process of chitin,one of the abundant biomass resources on the earth,not only follows the principles of green chemistry,but also has significant value in industrial applications.However,it is a great challenge to directly convert insoluble and rigid structured chitin to 5-hydroxymethylfurfural(HMF).To address this issue,we developed a green conversion process combining pretreatment and catalytic system.Chitin was first pretreated by hexafluoro isopropanol(HFIP),which somewhat disrupted the hydrogen bonding network within the chitin structure.Subsequently,formic acid(FA)and silicotungstic acid(STA)synergistically catalyzed the conversion to HMF in a biphasic system of 2-methyltetrahydrofuran(2-Me-THF)/H2O,and high yields(40.2%)HMF was obtained under the optimism conditions.The product distribution was analyzed by HPLC-MS and the co-catalysis of FA with STA was evidenced.A dual-function catalytic system with both Lewis and Br?nsted acids was created,the catalytic system that significantly improved the efficiency of complex tandem catalytic reactions with chitin.Based on the experimental results,a possible pathway for chitin conversion was deduced,providing a new catalytic idea for the efficient conversion of chitin to HMF.
基金financially supported by the National Key Research and Development Program of China(2022YFA1505700,2019YFA0210403)the National Natural Science Foundation of China(52102216)+4 种基金the Natural Science Foundation of Fujian Province(2022J01625,2022-S-002)the Anhui Key Laboratory of Nanomaterials and Nanotechnology,the Major Science and Technology Projects in Anhui Province(202305a12020006)the Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(2025-22)the Innovation Training Program for College Students(cxxl-2024131,cxxl-2024136)support by Transmission Electron Microscope Platform and High-performance Computing Platform of Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China。
文摘Layered V_(2)O_(5) cathode holds the merits of high theoretical specific capacity(589 mA h g^(-1))in aqueous zinc-ion batteries(AZIBs),yet it still suffers from inferior bulk conductivity and structure degradation notably during prolonged cycling.Herein,we ingeniously design cations(Na^(+)/Co^(2+)/Al^(3+))and anion(F^(-))synergistic-doped hydrated V_(2)O_(5)·0.48H_(2)O cathode(VNACOF)to enhance the electronic and spatial effects in the bulk.A range of in-situ,ex-situ characterizations,and DFT calculations profoundly clarify the strengthened ionic/electronic conductivities,structural stability,and Zn^(2+)diffusion kinetics.As a result,the VNACOF displays a superior discharge capacity(529 mA h g^(-1)@0.1 C),rate capabilities(488 mA h g^(-1)@0.5 C,437 mA h g^(-1)@1C),and cycling stability(301 mA h g^(-1)@10 C@5000 cycles@93%)with sufficient energy density(393 W h kg^(-1)),Furthermore,the pouch-cells with high-load(60 mg)also deliver superior cyclic(2 C@178 mA h g^(-1)@1000 cycles@90%)and rate performance(132 mA h g^(-1)@5 C),revealing great application potential for high-energy-density and high-stability AZIBs.
