Density functional calculations have been used to study the mechanism of 1-phenyl-1-（3-pyridyl）ethene hydroformylation using rhodium catalyst.Our calculations reveal that the rate-determining step is the oxidative a...Density functional calculations have been used to study the mechanism of 1-phenyl-1-（3-pyridyl）ethene hydroformylation using rhodium catalyst.Our calculations reveal that the rate-determining step is the oxidative addition of hydrogen molecule and the preferred path is the one involving ts3ans for the lowest activation free-energy （ΔrGa）,63.8 kJ/mol.This reaction is demonstrated to be strong exothermic by-96.6 kJ/mol of branched products and-98.2 kJ/mol of linear products.And the predominant product is the linear 3-phenyl-3-（3-pyridal）propanal （pr-ns） determined by both thermodynamics and kinetics.These results are in agreement with the practicality experimental studies.展开更多
Effects of hydrochloride acid dealumination of mordenite(MOR) catalysts for the synthesis of 1-phenyl-1-xylyl ethane(PXE) were investigated. The structure and acidity of catalysts were characterized by XRD, BET, XRF, ...Effects of hydrochloride acid dealumination of mordenite(MOR) catalysts for the synthesis of 1-phenyl-1-xylyl ethane(PXE) were investigated. The structure and acidity of catalysts were characterized by XRD, BET, XRF, FT-IR, 27Al NMR and NH3-TPD techniques. The catalytic performance of the acid-treated MOR zeolites was studied through using the alkylation of o-xylene with styrene. The test results showed that the strength of remaining Br?nsted acid sites increased despite the reduction of total number of acid sites after dealumination, and the micropores of HMOR were slightly enlarged coupled with the formation of secondary mesopores. Additionally, the modified HMOR zeolites showed longer catalyst life with the styrene conversion rate retained. Among the catalysts employed in this study, the modified mordenite that was dealuminated by HCl(2 mol/L) could be used repeatedly without significant loss of activity and selectivity during six catalytic runs, which have been ascribed to its specific acidity and structural properties.展开更多
基金Supported by the Education Commission of Chongqing (kj070809)Chongqing Normal University (06XLY018)crosswise project of Sichuan Normal University
文摘Density functional calculations have been used to study the mechanism of 1-phenyl-1-（3-pyridyl）ethene hydroformylation using rhodium catalyst.Our calculations reveal that the rate-determining step is the oxidative addition of hydrogen molecule and the preferred path is the one involving ts3ans for the lowest activation free-energy （ΔrGa）,63.8 kJ/mol.This reaction is demonstrated to be strong exothermic by-96.6 kJ/mol of branched products and-98.2 kJ/mol of linear products.And the predominant product is the linear 3-phenyl-3-（3-pyridal）propanal （pr-ns） determined by both thermodynamics and kinetics.These results are in agreement with the practicality experimental studies.
基金the financial supports of the National Natural Science Foundation of China (Grant No. 21306023, 21376051, 21106017 and 51077013)the Fund Project for Transformation of Scientific and Technological Achievements of Jiangsu Province (Grant No. BA2011086)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100092120047)the Key Program for the Scientific Research Guiding Fund of Basic Scientific Research Operation Expenditure of Southeast University (Grant No. 3207043101)the Instrumental Analysis Fund of Southeast University
文摘Effects of hydrochloride acid dealumination of mordenite(MOR) catalysts for the synthesis of 1-phenyl-1-xylyl ethane(PXE) were investigated. The structure and acidity of catalysts were characterized by XRD, BET, XRF, FT-IR, 27Al NMR and NH3-TPD techniques. The catalytic performance of the acid-treated MOR zeolites was studied through using the alkylation of o-xylene with styrene. The test results showed that the strength of remaining Br?nsted acid sites increased despite the reduction of total number of acid sites after dealumination, and the micropores of HMOR were slightly enlarged coupled with the formation of secondary mesopores. Additionally, the modified HMOR zeolites showed longer catalyst life with the styrene conversion rate retained. Among the catalysts employed in this study, the modified mordenite that was dealuminated by HCl(2 mol/L) could be used repeatedly without significant loss of activity and selectivity during six catalytic runs, which have been ascribed to its specific acidity and structural properties.
