Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deproton...Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation,by which the IL based biomass processing will be challenging.Herein,we demonstrated that the thermal stability of normal acetate-based imidazolim[C8C1Im][OAc]could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL([C4C1Im][NTf2]).When the molar fraction of[C8C1Im][OAc]was 0.3,the thermal stability of[C8C1Im][OAc]could be significantly improved(ΔT5%dec=+43°C).Detailed information obtained from thermal gravimetric analysis(TGA)and nuclear magnetic resonance(NMR)revealed that the addition of[C4C1 Im][NTf2]played a significant role in enhancing the thermal stability of[C8C1Im][OAc].It was proposed that the formation of an anion–π+structure network between[C8C1 Im][OAc]and[C4C1Im][NTf2]via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.展开更多
Low cost processing of lignocellulosic biomass is of great importance for sustainable chemistry and engineering.Herein,a low cost system composed of 1-butyl-3-methylimidazolium chloride([C_(4)C_(1) im]Cl),HCl and form...Low cost processing of lignocellulosic biomass is of great importance for sustainable chemistry and engineering.Herein,a low cost system composed of 1-butyl-3-methylimidazolium chloride([C_(4)C_(1) im]Cl),HCl and formaldehyde(FA)was developed for the pretreatment of corn stalk at 80℃.The efficiency of this technology was compared with that in dioxane system or without FA addition.Due to FA stabilization,the extent of acid-hydrolysis of carbohydrate fraction can be significantly decreased while 70%above of lignin was removed with the pretreatment of[C_(4)C_(1) im]Cl/HCl/FA system at 80℃for 2 h.A maximum reducing sugar yield of 93.7%and glucose concentration of 7.0 mg·ml^(-1) were subsequently obtained from enzymatic hydrolysis of the slurry.There were great differences in compositions of small molecule degraded products obtained with FA addition or not.The present[C_(4)C_(1) im]C_(l) based system exhibits great potential of substituting volatile organic solvents(i.e.dioxane)in developing low cost lignocellulosic biomass pretreatment at low temperature.Also,this work would gain insight into understanding on the roles of stabilization methods on the economic improvement of IL based biomass processing.展开更多
Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectrosc...Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS)were applied to study the surface morphology and elemental composition of the golden yellow-colored conversion coating.Elec trochemic al impedance spectroscopy(EIS)was used to investigate the electrochemical performance of the conversion coatings with different colors.The corrosion resistance properties of the powder coatings were characterized using the neutral salt spray test(NSS)and the tape adhesion test.The EIS and NSS results demonstrate that the colored zirconium conversion coatings exhibit excellent corrosion resistance properties compared with the bare CRS.The golden yellow-colored conversion coating has a maximum EIS value(748Ω·cm^(2))and achieves 0 mm degree of corrosion,as stipulated by EN ISO 4628-8.This paper proposes a hypothesis concerning the ZrO_(2)-(β-FeOOH)-polymer conversion reaction to explain the color changes.展开更多
Syngas production from CO2 reforming of ethanol over an Ir/Ce O2 catalyst was investigated. Catalysts characterization was conducted by X-ray diffraction(XRD), temperature programmed reduction(TPR), transmission e...Syngas production from CO2 reforming of ethanol over an Ir/Ce O2 catalyst was investigated. Catalysts characterization was conducted by X-ray diffraction(XRD), temperature programmed reduction(TPR), transmission electron microscopy(TEM) and temperature programmed oxidation(TPO). The Ir/Ce O2 catalyst was more active and stable toward syngas formation(molar ratio ~1). The superior catalytic performance was interpreted in terms of the strong interaction between Ir particles and ceria support which was crucial for efficient ethanol/CO2 activation and coke removal on the catalyst surface.展开更多
基金financially supported by the National Natural Science Foundation of China(21776026)the Liaoning Revitalization Talents Program(XLYC1902037)the start-up research funding of Beijing Institute of Technology(3160011181808)。
文摘Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation,by which the IL based biomass processing will be challenging.Herein,we demonstrated that the thermal stability of normal acetate-based imidazolim[C8C1Im][OAc]could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL([C4C1Im][NTf2]).When the molar fraction of[C8C1Im][OAc]was 0.3,the thermal stability of[C8C1Im][OAc]could be significantly improved(ΔT5%dec=+43°C).Detailed information obtained from thermal gravimetric analysis(TGA)and nuclear magnetic resonance(NMR)revealed that the addition of[C4C1 Im][NTf2]played a significant role in enhancing the thermal stability of[C8C1Im][OAc].It was proposed that the formation of an anion–π+structure network between[C8C1 Im][OAc]and[C4C1Im][NTf2]via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.
基金supported by the National Natural Science Foun-dation of China(21776026,22078023)Liaoning Revitalization Talents Program(XLYC1902037).
文摘Low cost processing of lignocellulosic biomass is of great importance for sustainable chemistry and engineering.Herein,a low cost system composed of 1-butyl-3-methylimidazolium chloride([C_(4)C_(1) im]Cl),HCl and formaldehyde(FA)was developed for the pretreatment of corn stalk at 80℃.The efficiency of this technology was compared with that in dioxane system or without FA addition.Due to FA stabilization,the extent of acid-hydrolysis of carbohydrate fraction can be significantly decreased while 70%above of lignin was removed with the pretreatment of[C_(4)C_(1) im]Cl/HCl/FA system at 80℃for 2 h.A maximum reducing sugar yield of 93.7%and glucose concentration of 7.0 mg·ml^(-1) were subsequently obtained from enzymatic hydrolysis of the slurry.There were great differences in compositions of small molecule degraded products obtained with FA addition or not.The present[C_(4)C_(1) im]C_(l) based system exhibits great potential of substituting volatile organic solvents(i.e.dioxane)in developing low cost lignocellulosic biomass pretreatment at low temperature.Also,this work would gain insight into understanding on the roles of stabilization methods on the economic improvement of IL based biomass processing.
基金financially supported by Shenzhen Technology Development Project(No.CXZZ20140902141250786)Guangdong Science and Technology Project(No.2014A010105004)。
文摘Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS)were applied to study the surface morphology and elemental composition of the golden yellow-colored conversion coating.Elec trochemic al impedance spectroscopy(EIS)was used to investigate the electrochemical performance of the conversion coatings with different colors.The corrosion resistance properties of the powder coatings were characterized using the neutral salt spray test(NSS)and the tape adhesion test.The EIS and NSS results demonstrate that the colored zirconium conversion coatings exhibit excellent corrosion resistance properties compared with the bare CRS.The golden yellow-colored conversion coating has a maximum EIS value(748Ω·cm^(2))and achieves 0 mm degree of corrosion,as stipulated by EN ISO 4628-8.This paper proposes a hypothesis concerning the ZrO_(2)-(β-FeOOH)-polymer conversion reaction to explain the color changes.
基金Project supported by the National Natural Science Foundation of China (No. 50973129) and Natural Science Foundation of Guangdong Province (No. 07001781).
基金supported by Foundation of National Natural Science Foundation of China(21303185)Key Laboratory of Renewable Energy and Gas Hydrate,Chinese Academy of Sciences(y407k21001)
文摘Syngas production from CO2 reforming of ethanol over an Ir/Ce O2 catalyst was investigated. Catalysts characterization was conducted by X-ray diffraction(XRD), temperature programmed reduction(TPR), transmission electron microscopy(TEM) and temperature programmed oxidation(TPO). The Ir/Ce O2 catalyst was more active and stable toward syngas formation(molar ratio ~1). The superior catalytic performance was interpreted in terms of the strong interaction between Ir particles and ceria support which was crucial for efficient ethanol/CO2 activation and coke removal on the catalyst surface.