A carbon-based sulfonated catalyst was prepared by direct sulfonation and carbonization （in moderate conditions：200 ＆#176;C, 12 h） of red liquor solids, a by-product of paper-making process. The prepared sulfonate...A carbon-based sulfonated catalyst was prepared by direct sulfonation and carbonization （in moderate conditions：200 ＆#176;C, 12 h） of red liquor solids, a by-product of paper-making process. The prepared sulfonated cata-lyst （SC） had aromatic structure, composed of carbon enriched inner core, and oxygen-containing （SO3H, COOH, OH） groups enriched surface. The SO3H, COOH, OH groups amounted to 0.74 mmol·g^-1, 0.78 mmol·g^-1, 2.18 mmol·g^-1, respectively. The fresh SC showed much higher catalytic activity than that of the traditional solid acid catalysts （strong^-acid 732 cation exchange resin, hydrogen type zeolite socony mobile-five （HZSM-5）, sulfated zir-conia） in esterification of oleic acid. SC was deactivated during the reactions, through the mechanisms of leaching of sulfonated species and formation of sulfonate esters. Two regeneration methods were developed, and the catalytic activity can be mostly regenerated by regeneration Method 1 and be fully regenerated by regeneration Method 2, respectively.展开更多
Based on starch and series of alkyl benzene sulfonic acid as the materials, a novel carbon-based solid acid catalyst is synthesized using hydrothermal method. This catalyst exhibits much higher catalytic activity in t...Based on starch and series of alkyl benzene sulfonic acid as the materials, a novel carbon-based solid acid catalyst is synthesized using hydrothermal method. This catalyst exhibits much higher catalytic activity in the reaction of esterification of Mono-fatty alcohol polyoxyethylene maleate esters with 1,4-butanediol. The structure of carbon-based solid acid catalyst was charactered by IR and XRD, characterizations showed that this catalyst exhibited high –SO3H loading. Reusability of the carbon-based solid acid catalyst for esterification showed that after recycling five times the activity remained unchanged.展开更多
Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspher...Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.展开更多
基金Supported by the State Key Development Program for Basic Research of China(2013CB228104,2010CB732205)Ph.D Programs Foundation of Ministry of Education of China(20120172110011)the National High Technology Research and Development Program of China(2012AA051801)
文摘A carbon-based sulfonated catalyst was prepared by direct sulfonation and carbonization （in moderate conditions：200 ＆#176;C, 12 h） of red liquor solids, a by-product of paper-making process. The prepared sulfonated cata-lyst （SC） had aromatic structure, composed of carbon enriched inner core, and oxygen-containing （SO3H, COOH, OH） groups enriched surface. The SO3H, COOH, OH groups amounted to 0.74 mmol·g^-1, 0.78 mmol·g^-1, 2.18 mmol·g^-1, respectively. The fresh SC showed much higher catalytic activity than that of the traditional solid acid catalysts （strong^-acid 732 cation exchange resin, hydrogen type zeolite socony mobile-five （HZSM-5）, sulfated zir-conia） in esterification of oleic acid. SC was deactivated during the reactions, through the mechanisms of leaching of sulfonated species and formation of sulfonate esters. Two regeneration methods were developed, and the catalytic activity can be mostly regenerated by regeneration Method 1 and be fully regenerated by regeneration Method 2, respectively.
文摘Based on starch and series of alkyl benzene sulfonic acid as the materials, a novel carbon-based solid acid catalyst is synthesized using hydrothermal method. This catalyst exhibits much higher catalytic activity in the reaction of esterification of Mono-fatty alcohol polyoxyethylene maleate esters with 1,4-butanediol. The structure of carbon-based solid acid catalyst was charactered by IR and XRD, characterizations showed that this catalyst exhibited high –SO3H loading. Reusability of the carbon-based solid acid catalyst for esterification showed that after recycling five times the activity remained unchanged.
基金financially supported by the National Natural Science Foundation of China(Nos.21875044,52073064,22005058 and 22005057)National Key R&D Program of China(No.2020YFB2008600)+3 种基金Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.20JC1415300)Program of Shanghai Academic Research Leader(No.19XD1420300)China Post-doctoral Science Foundation(Nos.2020M670973,BX20200085)the State Key Laboratory of Transducer Technology of China(No.SKT1904)。
文摘Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.
