Herein,a new mechanism involving Lewis acid-oxygen vacancy interfacial synergistic catalysis fo r aniline N,N-diethylation with ethanol was proposed,and the SO4^2-/Ce0.84Zr0.16O2-WO3-ZrO2 catalyst(SCWZ)with both Lewis...Herein,a new mechanism involving Lewis acid-oxygen vacancy interfacial synergistic catalysis fo r aniline N,N-diethylation with ethanol was proposed,and the SO4^2-/Ce0.84Zr0.16O2-WO3-ZrO2 catalyst(SCWZ)with both Lewis acid sites and oxygen vacancies was synthesized by the hydrothermal method,which shows better catalytic activity than the reported solid acidic catalysts.Besides,the SO4^2-/ZrO2(SZ)and SO4^2-/WO3-ZrO2(SWZ)catalysts were also prepared and compared with SCWZ to investigate the synergistic effect of each component.The SO4^2-and WO3 mainly generate Lewis acid by bonding with ZrO2,which is beneficial for the fracture of the N-H bond in aniline.The Ce0.84Zr0.16O2 solid solution mainly plays a vital role in generating the oxygen vacancies as the interface active species,which can participate in stripping-OH from ethanol,then the carbocation will also be released,which only needs1.3805 kcal/mol energy,calculated by density functional theory(DFT),to be input.In comparison,the traditional reaction mechanism needs the Br■nsted acidic sites to promote the protonation of ethanol,then dehydration and subsequent formation of carbocation followed,and 108.6846 kcal/mol energy needs to be input,which is far higher than that of the new mechanism.The apparent activation energy(Ea)over SCWZ was measured by experiment to be 34.09 kJ/mol,which is much lower than that of SWZ(47.10 kJ/mol)and SZ(54.37 kJ/mol),illustrating comparatively preferable kinetics for SCWZ than that of SWZ and SZ.Besides,the conversion of aniline and selectivity to N,N-diethylaniline over SCWZ reach almost 100%and 73%,respectively,The SCWZ can be renewed for 4 times without rapid deactivation,and the longevity of SCWZ is longer than that of SWZ and SZ,as the loaded SO4^2-and tetragonal ZrO2 are stabilized by Ce0.84Zr0.16O2 and WO3,respectively.展开更多
基金Project supported by China Petroleum&Chemical Corporation (J418013-3)。
文摘Herein,a new mechanism involving Lewis acid-oxygen vacancy interfacial synergistic catalysis fo r aniline N,N-diethylation with ethanol was proposed,and the SO4^2-/Ce0.84Zr0.16O2-WO3-ZrO2 catalyst(SCWZ)with both Lewis acid sites and oxygen vacancies was synthesized by the hydrothermal method,which shows better catalytic activity than the reported solid acidic catalysts.Besides,the SO4^2-/ZrO2(SZ)and SO4^2-/WO3-ZrO2(SWZ)catalysts were also prepared and compared with SCWZ to investigate the synergistic effect of each component.The SO4^2-and WO3 mainly generate Lewis acid by bonding with ZrO2,which is beneficial for the fracture of the N-H bond in aniline.The Ce0.84Zr0.16O2 solid solution mainly plays a vital role in generating the oxygen vacancies as the interface active species,which can participate in stripping-OH from ethanol,then the carbocation will also be released,which only needs1.3805 kcal/mol energy,calculated by density functional theory(DFT),to be input.In comparison,the traditional reaction mechanism needs the Br■nsted acidic sites to promote the protonation of ethanol,then dehydration and subsequent formation of carbocation followed,and 108.6846 kcal/mol energy needs to be input,which is far higher than that of the new mechanism.The apparent activation energy(Ea)over SCWZ was measured by experiment to be 34.09 kJ/mol,which is much lower than that of SWZ(47.10 kJ/mol)and SZ(54.37 kJ/mol),illustrating comparatively preferable kinetics for SCWZ than that of SWZ and SZ.Besides,the conversion of aniline and selectivity to N,N-diethylaniline over SCWZ reach almost 100%and 73%,respectively,The SCWZ can be renewed for 4 times without rapid deactivation,and the longevity of SCWZ is longer than that of SWZ and SZ,as the loaded SO4^2-and tetragonal ZrO2 are stabilized by Ce0.84Zr0.16O2 and WO3,respectively.
