A series of SO 2- 4/TiO 2 SiO 2 catalysts with different mass fractions of SiO 2 were prepared by sol gel method. The effect of adding SiO 2 on the crystal structure, specific surface area, oxygen adsorption, and acid...A series of SO 2- 4/TiO 2 SiO 2 catalysts with different mass fractions of SiO 2 were prepared by sol gel method. The effect of adding SiO 2 on the crystal structure, specific surface area, oxygen adsorption, and acidity of SO 2- 4/TiO 2 catalyst and its photocatalytic property for degradation of bromomethane was studied. The results showed that the specific surface area and amount of oxygen adsorption of catalyst were increased by addition of SiO 2, leading to the obvious increase on photocatalytic activity of SO 2- 4/TiO 2 SiO 2 catalysts and mineralization ratio of bromomethane. Comparing with SO 2- 4/TiO 2, the acidic strength and anti moisture ability of SO 2- 4/TiO 2 SiO 2 catalyst were decreased.展开更多
The preparation of peroxodisulfated zirconia titania(PSZT) solid super acid has been investigated as function of molar ratio of Ti to Zr, impregnation time, calcination time and temperature in esterification of maleic...The preparation of peroxodisulfated zirconia titania(PSZT) solid super acid has been investigated as function of molar ratio of Ti to Zr, impregnation time, calcination time and temperature in esterification of maleic anhydride with n octanol. The highest yield of dioctyl maleate was 98 2% at the optimum reaction conditions.展开更多
Ultra fine SO 2- 4/TiO 2-SiO 2 complex catalysts were synthesized by the one-step calcination method,which used titania sulfate and white carbon as raw materials and polyvinyl alcohol as dispersing agent. Catalysts ar...Ultra fine SO 2- 4/TiO 2-SiO 2 complex catalysts were synthesized by the one-step calcination method,which used titania sulfate and white carbon as raw materials and polyvinyl alcohol as dispersing agent. Catalysts are characterized by XRDIRTDA and BET. Different preparation factors were discussed.The catalysts consisting of SO 2- 43.4% and TiO 2∶SiO 2=1∶6 showed excellent reaction activity and stability for the photocatalytic degradation of phenol.Controlling calcination temperature and time (450℃,2h) could avoid or diminish the formation of Ti-O-Si bond and obtain higher V g and better dispersivity of TiO 2 on the surface of SiO 2.The kinetic study on photocatalytic degradation of phenol with the complex catalysts in a suspension system under 40W UV-lamp showed that apparent rate constant k conformed to a zero-order kinetic model at initial concentration <100mg·L -1 and increased with increasing pH value of phenol solution up to pH=12.When pH=10,k=3.32×10 -1 mg·L -1 ·min -1 . Solar photocatalytic experiment also gave good results.展开更多
Catalytic aryl ether C—O bonds hydrogenolysis was an important route to convert lignite into high valueadded chemicals.Solid super acid 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalysts were successfully synthesized and evalua...Catalytic aryl ether C—O bonds hydrogenolysis was an important route to convert lignite into high valueadded chemicals.Solid super acid 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalysts were successfully synthesized and evaluated their performance in catalytic hydrolysis of lignite derivatives.The excellent performance of 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) stems from the synergistic interaction between metallic and acidic sites.Specifically,the acidic sites generated by S_(2)O_(8)^(2-) facilitate the adsorption of O atoms in the substrate,whereas the metal sites optimize the process of hydrogen adsorption and activation and promote the generation of hydrogen radicals,which further enhances the ability to break C—O bonds.Thus,10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) exhibits more significantcatalytic activity compared to 10%Ni-ZrO_(2) prepared from pure ZrO_(2) as a support.Characterization results showed that the 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalyst prepared by sodium borohydride reduction method presented a uniform pore structure,which effectively promoted the dispersion of metal Ni on the catalyst surface.Complete conversion of diphenyl ether(DPE)can be achieved under relatively mild conditions,and excellent hydrogenolysis activity is also demonstrated for other lignite derivatives containing C—O bonds.The possible reaction mechanism of DPE hydrogenolysis in the H_(2)-isopropanol system was investigated.This work represents a significantstep forward in the design of highly efficientsolid super acid catalysts.展开更多
文摘A series of SO 2- 4/TiO 2 SiO 2 catalysts with different mass fractions of SiO 2 were prepared by sol gel method. The effect of adding SiO 2 on the crystal structure, specific surface area, oxygen adsorption, and acidity of SO 2- 4/TiO 2 catalyst and its photocatalytic property for degradation of bromomethane was studied. The results showed that the specific surface area and amount of oxygen adsorption of catalyst were increased by addition of SiO 2, leading to the obvious increase on photocatalytic activity of SO 2- 4/TiO 2 SiO 2 catalysts and mineralization ratio of bromomethane. Comparing with SO 2- 4/TiO 2, the acidic strength and anti moisture ability of SO 2- 4/TiO 2 SiO 2 catalyst were decreased.
文摘The preparation of peroxodisulfated zirconia titania(PSZT) solid super acid has been investigated as function of molar ratio of Ti to Zr, impregnation time, calcination time and temperature in esterification of maleic anhydride with n octanol. The highest yield of dioctyl maleate was 98 2% at the optimum reaction conditions.
文摘Ultra fine SO 2- 4/TiO 2-SiO 2 complex catalysts were synthesized by the one-step calcination method,which used titania sulfate and white carbon as raw materials and polyvinyl alcohol as dispersing agent. Catalysts are characterized by XRDIRTDA and BET. Different preparation factors were discussed.The catalysts consisting of SO 2- 43.4% and TiO 2∶SiO 2=1∶6 showed excellent reaction activity and stability for the photocatalytic degradation of phenol.Controlling calcination temperature and time (450℃,2h) could avoid or diminish the formation of Ti-O-Si bond and obtain higher V g and better dispersivity of TiO 2 on the surface of SiO 2.The kinetic study on photocatalytic degradation of phenol with the complex catalysts in a suspension system under 40W UV-lamp showed that apparent rate constant k conformed to a zero-order kinetic model at initial concentration <100mg·L -1 and increased with increasing pH value of phenol solution up to pH=12.When pH=10,k=3.32×10 -1 mg·L -1 ·min -1 . Solar photocatalytic experiment also gave good results.
基金supported by the National Key Research and Development Program of China(2022YFB4101100)the National Natural Science Foundation of China(22178375 and 22478414)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Catalytic aryl ether C—O bonds hydrogenolysis was an important route to convert lignite into high valueadded chemicals.Solid super acid 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalysts were successfully synthesized and evaluated their performance in catalytic hydrolysis of lignite derivatives.The excellent performance of 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) stems from the synergistic interaction between metallic and acidic sites.Specifically,the acidic sites generated by S_(2)O_(8)^(2-) facilitate the adsorption of O atoms in the substrate,whereas the metal sites optimize the process of hydrogen adsorption and activation and promote the generation of hydrogen radicals,which further enhances the ability to break C—O bonds.Thus,10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) exhibits more significantcatalytic activity compared to 10%Ni-ZrO_(2) prepared from pure ZrO_(2) as a support.Characterization results showed that the 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalyst prepared by sodium borohydride reduction method presented a uniform pore structure,which effectively promoted the dispersion of metal Ni on the catalyst surface.Complete conversion of diphenyl ether(DPE)can be achieved under relatively mild conditions,and excellent hydrogenolysis activity is also demonstrated for other lignite derivatives containing C—O bonds.The possible reaction mechanism of DPE hydrogenolysis in the H_(2)-isopropanol system was investigated.This work represents a significantstep forward in the design of highly efficientsolid super acid catalysts.
