The support of catalyst for the direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction was prepared by the sol-gel method. Compared with activated charcoal, molecular sieve, porous ceramics...The support of catalyst for the direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction was prepared by the sol-gel method. Compared with activated charcoal, molecular sieve, porous ceramics, hopcalite, the support prepared by the sol-gel method has higher activity. The characterization of the support by X-ray diffraction (XRD) and transmission electron microscope (TEM) show that the mare crystal phase is Co2MnO4 and the average particle diameter is about 40 nm. The optimum conditions for synthesis of the support were determined by orthogonal experiments, which indicate that the proportion of Cu, Mn, and Co is the first important factor influencing the yield and selectivity of DPC. Temperature of calcination is the second one. The optimum conditions are: molar proportion of Cu, Mn, and Co being 1 : 1 : 1, temperature of calcination 700℃, drying at 100~C, temperature of water bath 85~C. The yield and selectivity of DPC in the process can reach 38% and 99% in the batch operation, respectively. The copper cobalt manganese mixed oxides chosen as the support contribute more to the high catalytic activity than the sol-gel method.展开更多
A carbon-based sulfonated catalyst was prepared by direct sulfonation and carbonization (in moderate conditions:200 °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 °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
High performance enzymatic synthesis of oleyl palmitate, a wax ester was carried out by lipase-catalyzed esterification of palmitic acid and oleyl alcohol. Response surface methodology (RSM) based on 5-level, 3-vari...High performance enzymatic synthesis of oleyl palmitate, a wax ester was carried out by lipase-catalyzed esterification of palmitic acid and oleyl alcohol. Response surface methodology (RSM) based on 5-level, 3-variable of centre composite rotatable design (CCRD) was used to evaluate the interactive effects of synthesis, of temperature (40-60 ℃); amount of enzyme (0.1-0.4 g) and substrate molar ratio of oleyl alcohol to palmitic acid (1:1-4:1) on the percentage yield of wax ester. All reactions were fixed at 1 hour of reaction time. The optimum condition obtained from RSM for the reactions were temperature of 57.9 ℃, enzyme amount of 0.26 g and molar ratio of substrates of 2.92. The actual experimental yield was 91.2% under the optimum condition, which compared well with the maximum predicted value of 92.0%. Comparison of predicted and experimental values reveal good correspondence between them, implying that empirical models derived from RSM can be used to adequately describe the relationship between the factors and response in the synthesis of oleyl palmitate.展开更多
文摘The support of catalyst for the direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction was prepared by the sol-gel method. Compared with activated charcoal, molecular sieve, porous ceramics, hopcalite, the support prepared by the sol-gel method has higher activity. The characterization of the support by X-ray diffraction (XRD) and transmission electron microscope (TEM) show that the mare crystal phase is Co2MnO4 and the average particle diameter is about 40 nm. The optimum conditions for synthesis of the support were determined by orthogonal experiments, which indicate that the proportion of Cu, Mn, and Co is the first important factor influencing the yield and selectivity of DPC. Temperature of calcination is the second one. The optimum conditions are: molar proportion of Cu, Mn, and Co being 1 : 1 : 1, temperature of calcination 700℃, drying at 100~C, temperature of water bath 85~C. The yield and selectivity of DPC in the process can reach 38% and 99% in the batch operation, respectively. The copper cobalt manganese mixed oxides chosen as the support contribute more to the high catalytic activity than the sol-gel method.
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 °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High performance enzymatic synthesis of oleyl palmitate, a wax ester was carried out by lipase-catalyzed esterification of palmitic acid and oleyl alcohol. Response surface methodology (RSM) based on 5-level, 3-variable of centre composite rotatable design (CCRD) was used to evaluate the interactive effects of synthesis, of temperature (40-60 ℃); amount of enzyme (0.1-0.4 g) and substrate molar ratio of oleyl alcohol to palmitic acid (1:1-4:1) on the percentage yield of wax ester. All reactions were fixed at 1 hour of reaction time. The optimum condition obtained from RSM for the reactions were temperature of 57.9 ℃, enzyme amount of 0.26 g and molar ratio of substrates of 2.92. The actual experimental yield was 91.2% under the optimum condition, which compared well with the maximum predicted value of 92.0%. Comparison of predicted and experimental values reveal good correspondence between them, implying that empirical models derived from RSM can be used to adequately describe the relationship between the factors and response in the synthesis of oleyl palmitate.