A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, ...A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, low-angle XRD, N2 adsorption-desorption, transmission electron microscopy, and ultraviolet-visible spectroscopy. The catalyst activity was investigated in the direct bydroxylation of benzene to phenol using H2O2 as the oxidant. Various operating variables, namely reaction temperature, reaction time, amount of H2O2, and catalyst dosage, were optimized using central composite design combined with response surface methodology （RSM）. The results showed that the correla- tion between the independent parameters and phenol yield was represented by a second-order polynomial model. The high correlation coefficient （R2）, i.e., 0.985, showed that the data predicted using RSM were in good agreement with the experimental results. The optimization results also showed that high selectivity for phenol was achieved at the optimized values of the operating variables： reaction temperature 324 K, reaction time 8 h, H2O2 content 3.28 mL, and catalyst dosage 0.09 g. This study showed that RSM was a reliable method for optimizing process variables for benzene hydroxylation to phenol.展开更多
Mesoporous Ti-Mo mixed oxides were prepared via a facile approach using stearic acid as the template, and were characterized using XRD FT-IR, nitrogen adsorption-desorption isotherm and TEM techniques. The catalytic a...Mesoporous Ti-Mo mixed oxides were prepared via a facile approach using stearic acid as the template, and were characterized using XRD FT-IR, nitrogen adsorption-desorption isotherm and TEM techniques. The catalytic activity of the prepared mesoporous Ti-Mo mixed oxides was first evaluated for the dehydration of fructose to 5-hydroxymethylfurfural(HMF), and a 50.3% yield of HMF was obtained within 60min at 120℃. Moreover, moderate yields of HMF could also be achieved from glucose and sucrose. The mesoporous catalyst could be simply separated from the reaction mixture after termination of the reaction and reused five times with no significant loss of catalytic activity.展开更多
Bi-metallic(Pt–Sn and Sn–Ni) and tri-metallic(Pt–Sn–Ni) catalysts,supported on Al-containing hexagonal mesoporous silica(Al-HMS)(Si/Al = 20) materials,were synthesized.N_2 adsorption–desorption,X-ray diffraction(...Bi-metallic(Pt–Sn and Sn–Ni) and tri-metallic(Pt–Sn–Ni) catalysts,supported on Al-containing hexagonal mesoporous silica(Al-HMS)(Si/Al = 20) materials,were synthesized.N_2 adsorption–desorption,X-ray diffraction(XRD),Brunauer–Emmett–Teller(BET) test,and temperature programed desorption(NH3-TPD)were used to characterize physicochemical characteristics and textural properties of the Al-HMS catalysts.Catalytic performances on hydro-cracking of n-decane at different reaction conditions were studied in a microreactor.Comparison between Pt–Sn,Sn–Ni and Pt–Sn–Ni catalyst under different hydro-cracking conditions was made.The experimental results indicate that the proper balance between the acid and metal functions is the key in synthesizing a catalyst with a better performance in hydro-cracking.Tri-metallic catalyst exhibits the best catalytic performance in n-decane hydro-cracking than two bi-metallic catalysts.展开更多
N-Phenylpyrrolidine was efficiently synthesized over the mesoporous A1203 catalyst by the reaction of the aniline and 1,4-butylene-glycol at atmospheric pressure. The catalyst exhibited very high activity and selectiv...N-Phenylpyrrolidine was efficiently synthesized over the mesoporous A1203 catalyst by the reaction of the aniline and 1,4-butylene-glycol at atmospheric pressure. The catalyst exhibited very high activity and selectivity. At the reaction temperature of 300~C, 1,4-butylene glycol conversion attained 100% and the selectivity of N-phenylpyrrolidine could exceed 98%.展开更多
Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supp...Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supported catalysts in catalytic methane combustion due to excellent hydrothermal stability and sulfur resistance. Recently, the emergence of nanostructured perovskite oxides（such as threedimensional ordered nanostructure, nano-array structure） with outstanding catalytic activity has further driven methane catalytic combustion research into spotlight. In this review, we summarize the recent development of nanostructured perovskite oxide catalysts for methane combustion, and shed some light on the rational design of high efficient nanostructured perovskite catalysts via lattice oxygen activation,lattice oxygen mobility and materials morphology engineering. The emergent issues needed to be addressed on perovskite catalysts were also proposed.展开更多
Mesoporous silica-zirconia supported phosphotungstic acid was synthesized by evaporation induced self-assembly method and used as oxidative desulfurization catalysts. The structural properties of as-prepared catalysts...Mesoporous silica-zirconia supported phosphotungstic acid was synthesized by evaporation induced self-assembly method and used as oxidative desulfurization catalysts. The structural properties of as-prepared catalysts were characterized using various analytical techniques including X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption desorption. The experimental results showed that HPW was highly dispersed on mesoporous framework. The surface acidity of catalysts was analyzed by FTIR measurement of adsorbed pyridine.The surface Lewis acidity was improved with increasing the content of zirconium in the samples. The mesoporous composites were used as catalysts with H2O2 as oxidant for oxidative desulfurization of model fuel. The catalytic activity results showed that the surface Lewis acid sites acted as selective adsorption active sites for dibenzothiophene, which facilitated the sulfur removal from model fuel in the presence of arene. A slight decrease in activity of the recovered catalyst used in the proceeding rounds indicated the reusability of the catalyst.展开更多
CONSPECTUS:Mesoporous metals,characterized by interconnected pore networks,high specific surface area,and exceptional mass transport properties,epitomize the pinnacle of catalyst design.These attributes are critical f...CONSPECTUS:Mesoporous metals,characterized by interconnected pore networks,high specific surface area,and exceptional mass transport properties,epitomize the pinnacle of catalyst design.These attributes are critical for fully exposing active sites and enabling rapid diffusion of reactants and products,particularly during demanding electrochemical and chemical transformations.Historically,synthesizing such intricate metallic nanostructures has long centered predominantly on the templated approaches.This involves using soft templates and/or hard templates to define the mesopore architecture.While effective for mesopore generation,the mandatory template removal step imposes a critical limitation to surface contamination.Residual surfactant-derived species,carbonaceous deposits,or silica fragments persistently coat on metal surfaces,obscuring catalytically active sites,altering their electronic structures,and impeding reactant accesses.Such contamination fundamentally undermines the intrinsic catalytic potential of metals.Consequently,the development of template-free synthetic strategies capable of directly generating mesoporous metals while preserving atomically clean surfaces has emerged as a pressing imperative and transformative frontier in catalysis science.This Account critically examines the burgeoning area of template-free methodologies for preparing mesoporous metals with surfaceclean sites.The focus centers squarely on three principal template-free synthetic routes:metal oxide atomic reconstruction,metal salt thermal decomposition,and dealloying.These routes inherently avoid surface impurities by eliminating templates.Crucially,we dissect the mechanistic links between these synthetic routes and formation of surface-clean sites,emphasizing how the absence of template residues directly translates to enhancing catalytic activity and stability and optimizing selectivity.This work not only addresses a critical gap by offering a systematic analysis of template-free synthesis of mesoporous metals but also establishes a structure-property paradigm for rational design of highly active mesoporous metal catalysts.This paves the way for scalable applications in clean energy technologies and carbon neutrality initiatives,positioning surface-clean mesoporous metals as an essential platform for sustainable catalysis.展开更多
Mesoporous carbon-supported cobalt （Co-MC） catalysts are widely applied as electrode materials for bat- teries. Conversely, the development of Co-MC as bifunctional catalysts for application in organic catalytic rea...Mesoporous carbon-supported cobalt （Co-MC） catalysts are widely applied as electrode materials for bat- teries. Conversely, the development of Co-MC as bifunctional catalysts for application in organic catalytic reactions and degradation of water contaminants is slower. Herein, the catalyst displayed high activity in the selective oxidation of toluene to benzaldehyde under mild conditions, attaining a high selectivity of 92.3%. Factors influencing the catalytic reaction performance were also investigated. Additionally, Co-MC displayed remarkable catalytic activity in degrading dyes relative to the pure metal counterpart. Moreover, the catalyst exhibited excellent reusability, as determined by the cyclic catalytic experiments. The paper demonstrates the potential of Co-MC as a bifunctional catalyst for both toluene selective oxidation and water contaminant degradation.展开更多
基金the University of Tehran for financial support of this work
文摘A Cr/SBA-16 catalyst was prepared using Cr（NO3）3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction （XRD）, low-angle XRD, N2 adsorption-desorption, transmission electron microscopy, and ultraviolet-visible spectroscopy. The catalyst activity was investigated in the direct bydroxylation of benzene to phenol using H2O2 as the oxidant. Various operating variables, namely reaction temperature, reaction time, amount of H2O2, and catalyst dosage, were optimized using central composite design combined with response surface methodology （RSM）. The results showed that the correla- tion between the independent parameters and phenol yield was represented by a second-order polynomial model. The high correlation coefficient （R2）, i.e., 0.985, showed that the data predicted using RSM were in good agreement with the experimental results. The optimization results also showed that high selectivity for phenol was achieved at the optimized values of the operating variables： reaction temperature 324 K, reaction time 8 h, H2O2 content 3.28 mL, and catalyst dosage 0.09 g. This study showed that RSM was a reliable method for optimizing process variables for benzene hydroxylation to phenol.
基金financially supported by the Joint Science and Technology Funds of Guizhou Science and Technology Department of Anshun Municipal Government and the Anshun University (No. LH[2015]7694)the 2016 National Innovative Entrepreneurship Training Program for Undergraduates (No. 201510667020)
文摘Mesoporous Ti-Mo mixed oxides were prepared via a facile approach using stearic acid as the template, and were characterized using XRD FT-IR, nitrogen adsorption-desorption isotherm and TEM techniques. The catalytic activity of the prepared mesoporous Ti-Mo mixed oxides was first evaluated for the dehydration of fructose to 5-hydroxymethylfurfural(HMF), and a 50.3% yield of HMF was obtained within 60min at 120℃. Moreover, moderate yields of HMF could also be achieved from glucose and sucrose. The mesoporous catalyst could be simply separated from the reaction mixture after termination of the reaction and reused five times with no significant loss of catalytic activity.
文摘Bi-metallic(Pt–Sn and Sn–Ni) and tri-metallic(Pt–Sn–Ni) catalysts,supported on Al-containing hexagonal mesoporous silica(Al-HMS)(Si/Al = 20) materials,were synthesized.N_2 adsorption–desorption,X-ray diffraction(XRD),Brunauer–Emmett–Teller(BET) test,and temperature programed desorption(NH3-TPD)were used to characterize physicochemical characteristics and textural properties of the Al-HMS catalysts.Catalytic performances on hydro-cracking of n-decane at different reaction conditions were studied in a microreactor.Comparison between Pt–Sn,Sn–Ni and Pt–Sn–Ni catalyst under different hydro-cracking conditions was made.The experimental results indicate that the proper balance between the acid and metal functions is the key in synthesizing a catalyst with a better performance in hydro-cracking.Tri-metallic catalyst exhibits the best catalytic performance in n-decane hydro-cracking than two bi-metallic catalysts.
文摘N-Phenylpyrrolidine was efficiently synthesized over the mesoporous A1203 catalyst by the reaction of the aniline and 1,4-butylene-glycol at atmospheric pressure. The catalyst exhibited very high activity and selectivity. At the reaction temperature of 300~C, 1,4-butylene glycol conversion attained 100% and the selectivity of N-phenylpyrrolidine could exceed 98%.
基金the financial support from the Recruitment Program of Global Young Experts Start-up Fundthe Program of Introducing Talents of Discipline to Universities of China(111 Program, No. B17019)
文摘Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supported catalysts in catalytic methane combustion due to excellent hydrothermal stability and sulfur resistance. Recently, the emergence of nanostructured perovskite oxides（such as threedimensional ordered nanostructure, nano-array structure） with outstanding catalytic activity has further driven methane catalytic combustion research into spotlight. In this review, we summarize the recent development of nanostructured perovskite oxide catalysts for methane combustion, and shed some light on the rational design of high efficient nanostructured perovskite catalysts via lattice oxygen activation,lattice oxygen mobility and materials morphology engineering. The emergent issues needed to be addressed on perovskite catalysts were also proposed.
基金Funded by the National Natural Science Foundation of China(No.21106008)the Petro China Innovation Foundation(No.2013D-5006-0405)
文摘Mesoporous silica-zirconia supported phosphotungstic acid was synthesized by evaporation induced self-assembly method and used as oxidative desulfurization catalysts. The structural properties of as-prepared catalysts were characterized using various analytical techniques including X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption desorption. The experimental results showed that HPW was highly dispersed on mesoporous framework. The surface acidity of catalysts was analyzed by FTIR measurement of adsorbed pyridine.The surface Lewis acidity was improved with increasing the content of zirconium in the samples. The mesoporous composites were used as catalysts with H2O2 as oxidant for oxidative desulfurization of model fuel. The catalytic activity results showed that the surface Lewis acid sites acted as selective adsorption active sites for dibenzothiophene, which facilitated the sulfur removal from model fuel in the presence of arene. A slight decrease in activity of the recovered catalyst used in the proceeding rounds indicated the reusability of the catalyst.
基金support from the National Natural Science Foundation of China(22509035)the National Key Research and Development Program of China(2023YFC3905002)the Fundamental Research Funds for the Central Universities。
文摘CONSPECTUS:Mesoporous metals,characterized by interconnected pore networks,high specific surface area,and exceptional mass transport properties,epitomize the pinnacle of catalyst design.These attributes are critical for fully exposing active sites and enabling rapid diffusion of reactants and products,particularly during demanding electrochemical and chemical transformations.Historically,synthesizing such intricate metallic nanostructures has long centered predominantly on the templated approaches.This involves using soft templates and/or hard templates to define the mesopore architecture.While effective for mesopore generation,the mandatory template removal step imposes a critical limitation to surface contamination.Residual surfactant-derived species,carbonaceous deposits,or silica fragments persistently coat on metal surfaces,obscuring catalytically active sites,altering their electronic structures,and impeding reactant accesses.Such contamination fundamentally undermines the intrinsic catalytic potential of metals.Consequently,the development of template-free synthetic strategies capable of directly generating mesoporous metals while preserving atomically clean surfaces has emerged as a pressing imperative and transformative frontier in catalysis science.This Account critically examines the burgeoning area of template-free methodologies for preparing mesoporous metals with surfaceclean sites.The focus centers squarely on three principal template-free synthetic routes:metal oxide atomic reconstruction,metal salt thermal decomposition,and dealloying.These routes inherently avoid surface impurities by eliminating templates.Crucially,we dissect the mechanistic links between these synthetic routes and formation of surface-clean sites,emphasizing how the absence of template residues directly translates to enhancing catalytic activity and stability and optimizing selectivity.This work not only addresses a critical gap by offering a systematic analysis of template-free synthesis of mesoporous metals but also establishes a structure-property paradigm for rational design of highly active mesoporous metal catalysts.This paves the way for scalable applications in clean energy technologies and carbon neutrality initiatives,positioning surface-clean mesoporous metals as an essential platform for sustainable catalysis.
文摘Mesoporous carbon-supported cobalt （Co-MC） catalysts are widely applied as electrode materials for bat- teries. Conversely, the development of Co-MC as bifunctional catalysts for application in organic catalytic reactions and degradation of water contaminants is slower. Herein, the catalyst displayed high activity in the selective oxidation of toluene to benzaldehyde under mild conditions, attaining a high selectivity of 92.3%. Factors influencing the catalytic reaction performance were also investigated. Additionally, Co-MC displayed remarkable catalytic activity in degrading dyes relative to the pure metal counterpart. Moreover, the catalyst exhibited excellent reusability, as determined by the cyclic catalytic experiments. The paper demonstrates the potential of Co-MC as a bifunctional catalyst for both toluene selective oxidation and water contaminant degradation.
