Monoglyceride(MAG)is a widely used nonionic surfactant.In this work,an economic and green solid superbase HND-63 was utilized to synthesize monoglyceride,and the independent variables were examined to achieve the high...Monoglyceride(MAG)is a widely used nonionic surfactant.In this work,an economic and green solid superbase HND-63 was utilized to synthesize monoglyceride,and the independent variables were examined to achieve the highest MAG content.HND-63 was characterized in order to explore the potential reasons for its high MAG selectivity.At the same time,the catalytic mechanism of HND-63 in glycerolysis reaction was also focused on in this paper.A maximum of 72.50%MAG content was obtained under the optimal reaction parameters(reaction temperature of 110.5◦C,reaction time of 209 min,molar ratio of glycerol to oil of 9.2:1,and catalyst dosage of 10.1%).The activation energy Ea and the pre-exponential factor A of the reaction were 61.37 kJ/mol and 6.33×10^(6) mol·L^(-1)·min^(-1),respectively.The basic site of HND-63 is O^(2-),which is loaded on molecular sieve analogs in the form of Na_(2)O,thus providing great convenience for recovery.The findings offer a novel solid superbase that could be potentially applied to glycerolysis reactions,providing the foundation for further development of plantbased surfactants.展开更多
Thioxanthone-based N-phthalimidoamino acid ammonium salt（thioxanthen-DBU） as a photocaged base was synthesized and characterized. The photochemical properties and initiation mechanism were analyzed. It was found tha...Thioxanthone-based N-phthalimidoamino acid ammonium salt（thioxanthen-DBU） as a photocaged base was synthesized and characterized. The photochemical properties and initiation mechanism were analyzed. It was found that the compound absorbs over the UV and visible region with relatively high absorption coefficients. Furthermore, the covalent binding of N-phthalimidoamino acid and type II chromophores（thioxanthone, TX） remarkably improved the photoreactivity. Specifically, in combination with a benzoyl peroxide initiator, thioxanthen-DBU was able to initiate the amine-mediated redox photopolymerization of trimethylol propane triacrylate（TMPTA）, and an excellent photopolymerization profile was obtained.展开更多
LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane,giving 84%ethane conversion and 74%ethene yield at 923 K.Results indicated that the stro...LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane,giving 84%ethane conversion and 74%ethene yield at 923 K.Results indicated that the stronger the basicity of LiC1-based catalysts,the better the catalytic performance.展开更多
ACCORDING to Tanabe’s definition, all materials possessing the basic strength （H-） over 26.5 are superbases. However, most of superbases known up to now, including CaO and SrO evacuated at 1173 K, K or Na metal sup...ACCORDING to Tanabe’s definition, all materials possessing the basic strength （H-） over 26.5 are superbases. However, most of superbases known up to now, including CaO and SrO evacuated at 1173 K, K or Na metal supported on KOH/γ-Al<sub>2</sub>O<sub>3</sub>, etc. are extremely sensitive to CO<sub>2</sub> or H<sub>2</sub>O in the atmosphere, which limits their application in industrial scale. In or-展开更多
Carbon nanotubes(CNTs)are emerging as promising platforms for organic thermoelectric(TE)materials.However,the poor stability of n-doped states often presents a problem for the long-term operation of p-n junction TE mo...Carbon nanotubes(CNTs)are emerging as promising platforms for organic thermoelectric(TE)materials.However,the poor stability of n-doped states often presents a problem for the long-term operation of p-n junction TE modules.In this study,we synthesized a cross-linked organic superbase,2TBD-C10,as a dopant to create n-type CNTs that are resistant to air,heat,and humidity.When comparing the stability of 2TBD-C10-doped CNTs with those doped by a conventional superbase(TBD),we found that the enhanced stability could be attributed to the unique molecular structure of 2TBD-C10.This structure aids in effective adsorption on the CNT surfaces through multiple points,reduces volatility because of increased molecular weight,and suppresses water adsorption owing to the presence of hydrophobic alkyl chains.The results of our study demonstrate that tailoring the primary molecular structures of dopants can remarkably improve the stability of doped states in CNTs.The stable n-type materials were integrated into all-CNT TE modules,achieving good-to-excellent performance(power output of approximately 35μW from a temperature difference of approximately 65°C),making them suitable for powering wireless sensors and green light-emitting diodes.展开更多
Benzoylfonnamide（BFA） derivatives are proposed as new photocagcd bases with good solubility in epoxy resin.Initially their structures were confirmed by ~1H NMR,^（13）C NMR,and elemental analysis.Next,we detail thei...Benzoylfonnamide（BFA） derivatives are proposed as new photocagcd bases with good solubility in epoxy resin.Initially their structures were confirmed by ~1H NMR,^（13）C NMR,and elemental analysis.Next,we detail their thermal stability,solubility behavior,and photolysis products.Furthermore,the model photo-latent anion polymerization（AP） of epoxide system in the presence of BFA-dBA（N,N-dibenzyl-2-oxo-2-phenylacetamide） as a photocaged base has been investigated,and excellent photopolymerization profile is obtained.展开更多
Magnesium-related solid bases have long been considered catalysts with weak or medium basicity.Here we report the fabrication of Mg single-atom catalysts with superbasicity for the first time.A sublimation-migration-a...Magnesium-related solid bases have long been considered catalysts with weak or medium basicity.Here we report the fabrication of Mg single-atom catalysts with superbasicity for the first time.A sublimation-migration-anchoring strategy is employed,in which the Mg net is sublimated,transported by Ar,and trapped by defective graphene(producing Mg_(1)/G).Simulated and experimental results demonstrate that Mg single atoms are anchored on graphene in tetra-coordination,and Mg single atoms cooperating with C atoms give superbasicity,which differs from conventional alkali/alkaline earth metal oxides with basicity originating from O atoms.This new solid base is highly active in the synthesis of dimethyl carbonate through transesterification of ethylene carbonate with methanol,which is usually catalyzed by strong bases.The turnover frequency value reaches 99.6 h^(-1) on Mg_(1)/G,which is much higher than that of traditional Mg-related counterparts(1.0–5.6 h^(-1))and even superior to that of typical Na and K-related solid superbases(29.8–36.2 h^(-1))under similar conditions.展开更多
Progress on preparing strong basic and superbasic zeolites, mainly obtained in China during last decade has been reviewed. Strong basic sites are difficult to be generated on zeolite by common way, e.g. adjusting the ...Progress on preparing strong basic and superbasic zeolites, mainly obtained in China during last decade has been reviewed. Strong basic sites are difficult to be generated on zeolite by common way, e.g. adjusting the chemical composition of frameworks or loading alkali metal oxides/hydroxides owing to the special structure of zeolite. Through some novel methods展开更多
基金financially sponsored by Natural Science Foundation of Henan(252300421033).
文摘Monoglyceride(MAG)is a widely used nonionic surfactant.In this work,an economic and green solid superbase HND-63 was utilized to synthesize monoglyceride,and the independent variables were examined to achieve the highest MAG content.HND-63 was characterized in order to explore the potential reasons for its high MAG selectivity.At the same time,the catalytic mechanism of HND-63 in glycerolysis reaction was also focused on in this paper.A maximum of 72.50%MAG content was obtained under the optimal reaction parameters(reaction temperature of 110.5◦C,reaction time of 209 min,molar ratio of glycerol to oil of 9.2:1,and catalyst dosage of 10.1%).The activation energy Ea and the pre-exponential factor A of the reaction were 61.37 kJ/mol and 6.33×10^(6) mol·L^(-1)·min^(-1),respectively.The basic site of HND-63 is O^(2-),which is loaded on molecular sieve analogs in the form of Na_(2)O,thus providing great convenience for recovery.The findings offer a novel solid superbase that could be potentially applied to glycerolysis reactions,providing the foundation for further development of plantbased surfactants.
基金financially supported by National Natural Science Foundation of China(No.20974127,21374135)China Postdoctoral Science Foundation(No.2013M542178)+1 种基金the Open Foundation of the State Key Laboratory of Pulp and Paper Engineering in South China University of Technology(No.C713043z)the Fundamental Research Funds for the Central Universities(No.2013ZB0025)
文摘Thioxanthone-based N-phthalimidoamino acid ammonium salt（thioxanthen-DBU） as a photocaged base was synthesized and characterized. The photochemical properties and initiation mechanism were analyzed. It was found that the compound absorbs over the UV and visible region with relatively high absorption coefficients. Furthermore, the covalent binding of N-phthalimidoamino acid and type II chromophores（thioxanthone, TX） remarkably improved the photoreactivity. Specifically, in combination with a benzoyl peroxide initiator, thioxanthen-DBU was able to initiate the amine-mediated redox photopolymerization of trimethylol propane triacrylate（TMPTA）, and an excellent photopolymerization profile was obtained.
基金supported by the Ministry of Science and Technology of China(No.2005CB221408)the Science and Technology Projects of Hunan Province(No.2007FJ4151)
文摘LiCl-promoted superbase catalysts were found to be stable and highly selective to ethene for oxidative dehydrogenation of ethane,giving 84%ethane conversion and 74%ethene yield at 923 K.Results indicated that the stronger the basicity of LiC1-based catalysts,the better the catalytic performance.
文摘ACCORDING to Tanabe’s definition, all materials possessing the basic strength （H-） over 26.5 are superbases. However, most of superbases known up to now, including CaO and SrO evacuated at 1173 K, K or Na metal supported on KOH/γ-Al<sub>2</sub>O<sub>3</sub>, etc. are extremely sensitive to CO<sub>2</sub> or H<sub>2</sub>O in the atmosphere, which limits their application in industrial scale. In or-
基金supported in part by the A-STEP pro-gram of the Japan Science and Technology Agency(JST)(grant number JPMJTR23R6)a Grant-in-Aid for Scientific Research(KAKENHI)from the Japan Society for the Promotion of Science(JSPS)(grant number 23K13671).
文摘Carbon nanotubes(CNTs)are emerging as promising platforms for organic thermoelectric(TE)materials.However,the poor stability of n-doped states often presents a problem for the long-term operation of p-n junction TE modules.In this study,we synthesized a cross-linked organic superbase,2TBD-C10,as a dopant to create n-type CNTs that are resistant to air,heat,and humidity.When comparing the stability of 2TBD-C10-doped CNTs with those doped by a conventional superbase(TBD),we found that the enhanced stability could be attributed to the unique molecular structure of 2TBD-C10.This structure aids in effective adsorption on the CNT surfaces through multiple points,reduces volatility because of increased molecular weight,and suppresses water adsorption owing to the presence of hydrophobic alkyl chains.The results of our study demonstrate that tailoring the primary molecular structures of dopants can remarkably improve the stability of doped states in CNTs.The stable n-type materials were integrated into all-CNT TE modules,achieving good-to-excellent performance(power output of approximately 35μW from a temperature difference of approximately 65°C),making them suitable for powering wireless sensors and green light-emitting diodes.
基金financially supported by National Natural Science Foundation of China(No.21374135)China Postdoctoral Science Foundation(Nos.2013M542178 and 2014M562183)+1 种基金the Open Foundation of the State Key Laboratory of Pulp and Paper Engineering in South China University of Technology(No.C713043z)the Fundamental Research Funds for the Central Universities (No.2013ZB0025)
文摘Benzoylfonnamide（BFA） derivatives are proposed as new photocagcd bases with good solubility in epoxy resin.Initially their structures were confirmed by ~1H NMR,^（13）C NMR,and elemental analysis.Next,we detail their thermal stability,solubility behavior,and photolysis products.Furthermore,the model photo-latent anion polymerization（AP） of epoxide system in the presence of BFA-dBA（N,N-dibenzyl-2-oxo-2-phenylacetamide） as a photocaged base has been investigated,and excellent photopolymerization profile is obtained.
基金supported by the National Science Fund for Distinguished Young Scholars(22125804)the National Natural Science Foundation of China(22078155,21878149,U20A20151)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Magnesium-related solid bases have long been considered catalysts with weak or medium basicity.Here we report the fabrication of Mg single-atom catalysts with superbasicity for the first time.A sublimation-migration-anchoring strategy is employed,in which the Mg net is sublimated,transported by Ar,and trapped by defective graphene(producing Mg_(1)/G).Simulated and experimental results demonstrate that Mg single atoms are anchored on graphene in tetra-coordination,and Mg single atoms cooperating with C atoms give superbasicity,which differs from conventional alkali/alkaline earth metal oxides with basicity originating from O atoms.This new solid base is highly active in the synthesis of dimethyl carbonate through transesterification of ethylene carbonate with methanol,which is usually catalyzed by strong bases.The turnover frequency value reaches 99.6 h^(-1) on Mg_(1)/G,which is much higher than that of traditional Mg-related counterparts(1.0–5.6 h^(-1))and even superior to that of typical Na and K-related solid superbases(29.8–36.2 h^(-1))under similar conditions.
文摘Progress on preparing strong basic and superbasic zeolites, mainly obtained in China during last decade has been reviewed. Strong basic sites are difficult to be generated on zeolite by common way, e.g. adjusting the chemical composition of frameworks or loading alkali metal oxides/hydroxides owing to the special structure of zeolite. Through some novel methods
