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
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
Hierarchically structured macro-mesoporous carbon catalysts were synthesized using dual templates of poly(methyl methacrylate)(PMMA)and Pluronic-123 to enhance cellulose saccharification.Characterizations conducted th...Hierarchically structured macro-mesoporous carbon catalysts were synthesized using dual templates of poly(methyl methacrylate)(PMMA)and Pluronic-123 to enhance cellulose saccharification.Characterizations conducted through scanning electron microscopy(SEM),X-ray diffraction(XRD),N2 adsorption-desorption isotherms,Fourier transform infrared(FT-IR)spectroscopy,and titration techniques confirmed high surface areas and specific pore size distributions,with macropores ranging from 78.3 to 251 nm and mesopores around 2.43-6.23 nm.An optimal PMMA-to-Tetraethyl orthosilicate(TEOS)ratio of 1:1.6 facilitated the highest cellulose conversion rate of 59.3%and a glucose yield of 22.1%.Notably,the medium-sized macropore catalyst,MMCS60-M,outperformed its purely mesoporous counterpart,with conversion rates and glucose yields of 80.8% and 45.5%,respectively.These results suggest the importance of a tailored pore architecture to enhance the accessibility of acid sites and facilitate effective mass transport,which is beneficial for optimizing saccharification processes.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
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
Heterojunction nanocomposite electrocatalysts with porous structures and large specific surface areas show great potential in improving their intrinsic activity and the number of accessible active sites for oxygen evo...Heterojunction nanocomposite electrocatalysts with porous structures and large specific surface areas show great potential in improving their intrinsic activity and the number of accessible active sites for oxygen evolution reaction(OER).Herein,we describe an“exchanging sulfur for oxygen”protocol to fabricate a porous molybdate-based heterojunction electrocatalyst,Fe2(MoO4)3/CoMoO4,utilizing a sulfur-rich reagent,ammonium tetrathiomolybdate((NH4)2MoS4).During the calcination of the solid product formed from(NH4)2MoS4 and CoCl2/FeCl3,the sulfur atoms of MoS42-are oxidized into the acidic SO_(2)gas plus HCl and NH3 gases evolved in the system,which greatly facilitates the formation of macro/mesopores of the molybdate-based nanomaterial.It exhibits excellent electrocatalytic OER performance in alkaline media and only requires a low overpotential of 244 mV at a current density of 10 mA·cm^(-2) with outstanding durability.Experimental exami-nation and theoretical calculations reveal that its uniform interparticle porous structure enhances spatial connectivity and electrode–electrolyte contact,while strong electronic interactions at the heterointerface boost electrocatalytic activity.The phase combination increases interface electron concentration,accelerates charge transfer,and lowers free energy.This work provides a new strategy to construct the porous molybdate-based heterostructure electrocatalyst for remarkably boosting the OER performance.展开更多
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.
文摘Hierarchically structured macro-mesoporous carbon catalysts were synthesized using dual templates of poly(methyl methacrylate)(PMMA)and Pluronic-123 to enhance cellulose saccharification.Characterizations conducted through scanning electron microscopy(SEM),X-ray diffraction(XRD),N2 adsorption-desorption isotherms,Fourier transform infrared(FT-IR)spectroscopy,and titration techniques confirmed high surface areas and specific pore size distributions,with macropores ranging from 78.3 to 251 nm and mesopores around 2.43-6.23 nm.An optimal PMMA-to-Tetraethyl orthosilicate(TEOS)ratio of 1:1.6 facilitated the highest cellulose conversion rate of 59.3%and a glucose yield of 22.1%.Notably,the medium-sized macropore catalyst,MMCS60-M,outperformed its purely mesoporous counterpart,with conversion rates and glucose yields of 80.8% and 45.5%,respectively.These results suggest the importance of a tailored pore architecture to enhance the accessibility of acid sites and facilitate effective mass transport,which is beneficial for optimizing saccharification processes.
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.
基金the National Natural Science Foundation of China(Nos.U24A20507,22271203,22001021, 22478152)the State Key Laboratory of Organometallic Chemistry of Shanghai Institute of Organic Chemistry(No.2024KF005)Open Research Fund of State Key Laboratory of Coordination Chemistry,School of Chemistry and Chemical Engineering,Nanjing University,the Collaborative Innovation Center of Suzhou Nano Science and Technology,and the Project of Scientific and Technologic Infrastructure of Suzhou(No.SZS201905).
文摘Heterojunction nanocomposite electrocatalysts with porous structures and large specific surface areas show great potential in improving their intrinsic activity and the number of accessible active sites for oxygen evolution reaction(OER).Herein,we describe an“exchanging sulfur for oxygen”protocol to fabricate a porous molybdate-based heterojunction electrocatalyst,Fe2(MoO4)3/CoMoO4,utilizing a sulfur-rich reagent,ammonium tetrathiomolybdate((NH4)2MoS4).During the calcination of the solid product formed from(NH4)2MoS4 and CoCl2/FeCl3,the sulfur atoms of MoS42-are oxidized into the acidic SO_(2)gas plus HCl and NH3 gases evolved in the system,which greatly facilitates the formation of macro/mesopores of the molybdate-based nanomaterial.It exhibits excellent electrocatalytic OER performance in alkaline media and only requires a low overpotential of 244 mV at a current density of 10 mA·cm^(-2) with outstanding durability.Experimental exami-nation and theoretical calculations reveal that its uniform interparticle porous structure enhances spatial connectivity and electrode–electrolyte contact,while strong electronic interactions at the heterointerface boost electrocatalytic activity.The phase combination increases interface electron concentration,accelerates charge transfer,and lowers free energy.This work provides a new strategy to construct the porous molybdate-based heterostructure electrocatalyst for remarkably boosting the OER performance.
