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
Electrochemical water splitting is a facile and effective route to generate pure hydrogen and oxygen.However,the sluggish kinetics of hydrogen evolution reaction(HER) and especially oxygen evolution reaction(OER) hind...Electrochemical water splitting is a facile and effective route to generate pure hydrogen and oxygen.However,the sluggish kinetics of hydrogen evolution reaction(HER) and especially oxygen evolution reaction(OER) hinder the water splitting efficiency.Meanwhile,the high-cost of noble-metal catalysts limit their actual application.It is thus highly urgent to exploit an economical and earthabundant bifunctional HER and OER electrocatalyst to simplify procedure and reduce cost.Herein,we synthesize the three-dimensionally ordered macro-/mesoporous(3 DOM/m) Ni_(x)Co_(100-x) alloys with distinctive structure and large surface area via a dual-templating technique.Among them,the3 DOM/m Ni61Co39 shows the lowest overpotentials of 121 mV and 241 mV at 10 mA/cm^(2) for HER and OER,respectively.Furthermore,when employed for water splitting,the Ni_(61)Co_(39) only requires 1.60 V to approach 10 mA/cm^(2) and presents excellent stability.These encouraging performances of the Ni_(61)Co_(39) render it a promising bifunctional catalyst for overall water splitting.展开更多
A series of hierarchical macro-/mesoporous silica supports （MMSs） were successfully synthesized using dual-templating technique employing polystyrene （PS） spheres and the Pluronic P123 surfactant. Pd was next load...A series of hierarchical macro-/mesoporous silica supports （MMSs） were successfully synthesized using dual-templating technique employing polystyrene （PS） spheres and the Pluronic P123 surfactant. Pd was next loaded on the hierarchical silica supports via colloids precipitation method. Physicochemical properties of the synthesized samples were characterized by various techniques and all catalysts were tested for the total oxidation of o-xylene. Among them, the Pd/MMS-b catalyst with tetraethoxysilane/polystyrene weight ratio of 1.0 exhibited superior catalytic activity, and under a higher gas hourly space velocity （GHSV） of 70000 h^-1, the 90% conversion of o-xylene has been obtained at around 200℃. The BET and SEM results indicated that Pd/MMS- b catalyst possesses high surface area and large pore volume, and well-ordered, interconnected macropores and 2D hexagonally mesopores hybrid network. This novel ordered hierarchical porous structure was highly beneficial to the dispersion of active sites Pd nanoparticles with less aggregation, and facilitates diffusion of reactants and products. Furthermore, the Pd/MMS-b catalyst possessed good stability and durability.展开更多
金属锂具有超高的理论容量(3860 mAh·g^(−1))和低氧化还原电位(−3.04 V vs.标准氢电极),是极具吸引力的下一代高能量密度电池的负极材料。然而,循环过程中的体积膨胀、锂枝晶生长和“死锂”等问题严重的限制了其实际应用。合理设...金属锂具有超高的理论容量(3860 mAh·g^(−1))和低氧化还原电位(−3.04 V vs.标准氢电极),是极具吸引力的下一代高能量密度电池的负极材料。然而,循环过程中的体积膨胀、锂枝晶生长和“死锂”等问题严重的限制了其实际应用。合理设计三维骨架调控金属锂的成核行为是抑制锂枝晶生长的有效策略。本文中,我们发展了一种“软硬双模板”的方法合成了兼具大孔和介孔的三维碳-碳化钛(Three-dimensional macro-/mesoporous C-TiC,表示为3DMM-C-TiC)复合材料。多级孔道为金属锂的沉积提供了足够的空间,缓冲充放电中巨大的体积变化。此外,TiC的引入显著增强多孔骨架的导电性,改善锂金属的成核行为,促进金属锂的均匀成核和沉积,抑制锂枝晶生长。3DMM-C-TiC||Li电池测试表明,在循环300圈以后,库伦效率仍保持在98%以上。此外,所得材料与LiFePO_(4)(LFP)组成的全电池也表现出优异的倍率和循环性能。本工作为无枝晶锂金属负极的设计提供了新的思路。展开更多
The fabrication of polyoxometalates(POMs)-modified TiO_(2)catalysts with connected pore structure has attracted great interests due to its prominent effect on mass transfer and catalytic oxidation activity.Here,we rep...The fabrication of polyoxometalates(POMs)-modified TiO_(2)catalysts with connected pore structure has attracted great interests due to its prominent effect on mass transfer and catalytic oxidation activity.Here,we report a series of hierarchically macro/mesoporous(M/m)phosphotungstic acid(HPW)/TiO_(2)composites,which are fabricated by colloidal crystal template method and applied as deep desulfurization catalyst in fuel oil.As-synthesized hierarchical HPW/TiO_(2)composite is interconnected by ordered macroporous channel with disordered mesoporous embedded on pore walls.Moreover,Keggintype HPW is homogeneously dispersed on the TiO_(2)matrix.Hierarchical macro/mesoporous HPW/TiO_(2)shows an excellent catalytic performance,the removal rate for dibenzothiophene in model fuel reaches 99%under the optimum conditions.This high performance of the three-dimensional ordered macropores(3DOM)HPW/TiO_(2)can be attributed to its hierarchically porous which is highly beneficial for the mass transfer during the catalytic process.Moreover,the used catalyst could be regenerated by centrifugation and only slight decreasing of the catalytic activity after five cycles.展开更多
Hierarchically ordered macro-mesoporous TiO2 films (Ti-Ma-Me) were fabricated on fluorine-doped tin oxide (FTO) substrates through the confinement self-assembly method. The prepared Ti-Ma-Me possesses periodically ord...Hierarchically ordered macro-mesoporous TiO2 films (Ti-Ma-Me) were fabricated on fluorine-doped tin oxide (FTO) substrates through the confinement self-assembly method. The prepared Ti-Ma-Me possesses periodically ordered structure and a large specific surface area, which was applied as an interfacial layer between the nanocrystalline TiO2 film (P25-TiO2) and FTO electrode in the dye-sensitized solar cell (DSSC). The introduction of a Ti-Ma-Me interfacial layer increased the shortcircuit current density (Jsc) from 7.49 to 10.65 mA/cm2 and the open-circuit voltage (Voc) from 0.65 to 0.70 V as the result of its improved light harvesting efficiency by allowing for the high roughness factor and enhanced multiple internal reflection or scattering as well as reducing the back-transport reaction by blocking direct contact between the electrolyte and FTO electrode. Therefore, the photovoltaic conversion efficiency (η) was improved by 83% from 3.04% to 5.55%, as compared to a device using a bare P25 TiO2 photoanode.展开更多
Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,resp...Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,respectively.MMA had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 nm.Re2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular reactor.The result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3.展开更多
A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij...A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems.展开更多
This study described a template-flee method for the synthesis of hierarchically macro-mesoporous Mn- TiO2 catalysts. The promoting effect of Mn doping and the hierarchically macro-mesoporous architecture on TiO2 based...This study described a template-flee method for the synthesis of hierarchically macro-mesoporous Mn- TiO2 catalysts. The promoting effect of Mn doping and the hierarchically macro-mesoporous architecture on TiO2 based catalysts was also investigated for the selective reduction of NO with NH3. The results show that the catalytic performance of TiO2 based catalysts was improved greatly after Mn doping. Meanwhile, the Mn- TiO2 catalyst with the hierarchically macro-mesoporous architecture has a better catalytic activity than that without such an architecture.展开更多
Titania thin films with hierarchically macro-mesoporous were prepared by the addition of bulky organic molecule(1,3,5-trimethylbezenze) in aqueous solution of F127(EO106PO70EO106). After calcined at 673 K,ordered thin...Titania thin films with hierarchically macro-mesoporous were prepared by the addition of bulky organic molecule(1,3,5-trimethylbezenze) in aqueous solution of F127(EO106PO70EO106). After calcined at 673 K,ordered thin films with cubic meso-structure and macropores were formed. DNA(Cytochrome c) was used as probe to study the adsorption ability of macromolecules on this film. The hierarchically macro-mesoporous films show high adsorption ability of DNA molecules compared with conventional titania films and mesoporous titania films,which is attributed to the presence of macropores.展开更多
基金Supported by the National Natural Science Foundation of China(21276076)the Fundamental Research Funds for the Central Universities of China(WA1014003)State Key Laboratory of Chemical Engineering(SKL-ChE-10C06)
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.
基金financially supported by the National Natural Science Foundation of China (No.21676018 and 51172014)。
文摘Electrochemical water splitting is a facile and effective route to generate pure hydrogen and oxygen.However,the sluggish kinetics of hydrogen evolution reaction(HER) and especially oxygen evolution reaction(OER) hinder the water splitting efficiency.Meanwhile,the high-cost of noble-metal catalysts limit their actual application.It is thus highly urgent to exploit an economical and earthabundant bifunctional HER and OER electrocatalyst to simplify procedure and reduce cost.Herein,we synthesize the three-dimensionally ordered macro-/mesoporous(3 DOM/m) Ni_(x)Co_(100-x) alloys with distinctive structure and large surface area via a dual-templating technique.Among them,the3 DOM/m Ni61Co39 shows the lowest overpotentials of 121 mV and 241 mV at 10 mA/cm^(2) for HER and OER,respectively.Furthermore,when employed for water splitting,the Ni_(61)Co_(39) only requires 1.60 V to approach 10 mA/cm^(2) and presents excellent stability.These encouraging performances of the Ni_(61)Co_(39) render it a promising bifunctional catalyst for overall water splitting.
基金This work was financially supported by the National Natural Science Foundation （Grant Nos. 21337003 and 21477149）, and the Strategic Priority Research Program of the Chinese Academy of Sciences （XDB05050200）.
文摘A series of hierarchical macro-/mesoporous silica supports （MMSs） were successfully synthesized using dual-templating technique employing polystyrene （PS） spheres and the Pluronic P123 surfactant. Pd was next loaded on the hierarchical silica supports via colloids precipitation method. Physicochemical properties of the synthesized samples were characterized by various techniques and all catalysts were tested for the total oxidation of o-xylene. Among them, the Pd/MMS-b catalyst with tetraethoxysilane/polystyrene weight ratio of 1.0 exhibited superior catalytic activity, and under a higher gas hourly space velocity （GHSV） of 70000 h^-1, the 90% conversion of o-xylene has been obtained at around 200℃. The BET and SEM results indicated that Pd/MMS- b catalyst possesses high surface area and large pore volume, and well-ordered, interconnected macropores and 2D hexagonally mesopores hybrid network. This novel ordered hierarchical porous structure was highly beneficial to the dispersion of active sites Pd nanoparticles with less aggregation, and facilitates diffusion of reactants and products. Furthermore, the Pd/MMS-b catalyst possessed good stability and durability.
基金This work was supported by National Nature Science Foundation of China(Grant Nos.52104254,22008058,and 51901074).
文摘The fabrication of polyoxometalates(POMs)-modified TiO_(2)catalysts with connected pore structure has attracted great interests due to its prominent effect on mass transfer and catalytic oxidation activity.Here,we report a series of hierarchically macro/mesoporous(M/m)phosphotungstic acid(HPW)/TiO_(2)composites,which are fabricated by colloidal crystal template method and applied as deep desulfurization catalyst in fuel oil.As-synthesized hierarchical HPW/TiO_(2)composite is interconnected by ordered macroporous channel with disordered mesoporous embedded on pore walls.Moreover,Keggintype HPW is homogeneously dispersed on the TiO_(2)matrix.Hierarchical macro/mesoporous HPW/TiO_(2)shows an excellent catalytic performance,the removal rate for dibenzothiophene in model fuel reaches 99%under the optimum conditions.This high performance of the three-dimensional ordered macropores(3DOM)HPW/TiO_(2)can be attributed to its hierarchically porous which is highly beneficial for the mass transfer during the catalytic process.Moreover,the used catalyst could be regenerated by centrifugation and only slight decreasing of the catalytic activity after five cycles.
基金supported by the National Natural Science Foundation of China (20971125, 21031005, 21050110428 & 21006116)Beijing Municipal Natural Science Foundation (2082022)+2 种基金the Foundation for State Key Laboratory of Multi-phase Complex Systems (MPCS-2011-D-15)State Key Laboratory of Biochemical Engineering (2010KF-09)the CAS Research Fellowship for International Young Scientists (2010Y1GB5)
文摘Hierarchically ordered macro-mesoporous TiO2 films (Ti-Ma-Me) were fabricated on fluorine-doped tin oxide (FTO) substrates through the confinement self-assembly method. The prepared Ti-Ma-Me possesses periodically ordered structure and a large specific surface area, which was applied as an interfacial layer between the nanocrystalline TiO2 film (P25-TiO2) and FTO electrode in the dye-sensitized solar cell (DSSC). The introduction of a Ti-Ma-Me interfacial layer increased the shortcircuit current density (Jsc) from 7.49 to 10.65 mA/cm2 and the open-circuit voltage (Voc) from 0.65 to 0.70 V as the result of its improved light harvesting efficiency by allowing for the high roughness factor and enhanced multiple internal reflection or scattering as well as reducing the back-transport reaction by blocking direct contact between the electrolyte and FTO electrode. Therefore, the photovoltaic conversion efficiency (η) was improved by 83% from 3.04% to 5.55%, as compared to a device using a bare P25 TiO2 photoanode.
基金supported by the National Natural Science Foundation of China (Grant No:20976192)SINOPEC Jiujiang Petrochemical Company (G2810-09-ZS-0027)
文摘Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,respectively.MMA had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 nm.Re2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular reactor.The result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3.
基金Project supported by the National Natural Science Foundation of China(U1662103,21673290)Beijing Natural Science Foundation(2182060).
文摘A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems.
基金Acknowledgements This work was carried out in the framework of a program for Changjiang Scholars and Innovative Research Team （IRT_15R52） of the Chinese Ministry of Education. B. L. Su acknowledges the Chinese Central Government for an ＂Expert of the State＂ position in the Program of the ＂Thousand Talents＂, the Chinese Ministry of Education for a ＂Changjiang Chaire Professor＂ position and a Clare Hall Life Membership at the Clare Hall College and the financial support of the Department of Chemistry, University of Cambridge. L.H. CHEN acknowledges Hubei Provincial Department of Education for the ＂Chutian Scholar＂ program. This work was also financially supported by the National Natural Science Foundation of China （Grant Nos. 21671155 and U1663225）, Scientific Research Foundation for the Returned Oversea Chinese Scholars, State Education Ministry （[2015 ]311）, Hubei Provincial Natural Science Founda- tion （2015CFB428）.
文摘This study described a template-flee method for the synthesis of hierarchically macro-mesoporous Mn- TiO2 catalysts. The promoting effect of Mn doping and the hierarchically macro-mesoporous architecture on TiO2 based catalysts was also investigated for the selective reduction of NO with NH3. The results show that the catalytic performance of TiO2 based catalysts was improved greatly after Mn doping. Meanwhile, the Mn- TiO2 catalyst with the hierarchically macro-mesoporous architecture has a better catalytic activity than that without such an architecture.
文摘Titania thin films with hierarchically macro-mesoporous were prepared by the addition of bulky organic molecule(1,3,5-trimethylbezenze) in aqueous solution of F127(EO106PO70EO106). After calcined at 673 K,ordered thin films with cubic meso-structure and macropores were formed. DNA(Cytochrome c) was used as probe to study the adsorption ability of macromolecules on this film. The hierarchically macro-mesoporous films show high adsorption ability of DNA molecules compared with conventional titania films and mesoporous titania films,which is attributed to the presence of macropores.
