以无助剂的二氧化硅溶胶为胶液,通过离心喷雾干燥制备球径可控的微米钛硅分子筛催化剂(TS-1)微球。考察了成型过程中进料速度、喷雾成型温度等工艺参数对分子筛成球、球径以及球形度的影响,并初步探讨了成球机制。结果表明,成型温度为17...以无助剂的二氧化硅溶胶为胶液,通过离心喷雾干燥制备球径可控的微米钛硅分子筛催化剂(TS-1)微球。考察了成型过程中进料速度、喷雾成型温度等工艺参数对分子筛成球、球径以及球形度的影响,并初步探讨了成球机制。结果表明,成型温度为170℃、进料速度为8 m L/min时可制备出球形度良好、球径集中分布于55μm的钛硅分子筛微球。将其用于环己酮氨肟化反应中,在环己酮空速为12 h-1催化反应中,寿命为28 h(转化率>90%)。优异的催化性能归因于分子筛微球高的比表面积、丰富的孔结构以及微球中含硅非活性成分抑制了钛硅分子筛骨架钛流失。展开更多
The hollow α-MnO2 nanoneedle-based microspheres coated with Pd nanoparticles were reported as a novel catalyst for rechargeable lithium-air batteries. The hollow microspheres are composed ofα-MnO2 nanoneedles. Pd na...The hollow α-MnO2 nanoneedle-based microspheres coated with Pd nanoparticles were reported as a novel catalyst for rechargeable lithium-air batteries. The hollow microspheres are composed ofα-MnO2 nanoneedles. Pd nanoparticles are deposited on the hollow microspheres through an aqueous-solution reduction of PdCl2 with NaBH4 at room temperature. The results of TEM, XRD, and EDS show that the Pd nanoparticles are coated on the surface ofα-MnO2 nanoneedles uniformly and the mass fraction of Pd in the Pd-coated α-MnO2 catalyst is about 8.88%. Compared with the counterpart of the hollow α-MnO2 catalyst, the hollow Pd-coated α-MnO2 catalyst improves the energy conversion efficiency and the charge-discharge cycling performance of the air electrode. The initial specific discharge capacity of an air electrode composed of Super P carbon and the as-prepared Pd-coatedα-MnO2 catalyst is 1220 mA＆#183;h/g （based on the total electrode mass） at a current density of 0.1 mA/cm2, and the capacity retention rate is about 47.3% after 13 charge-discharge cycles. The results of charge-discharge cycling tests demonstrate that this novel Pd-coatedα-MnO2 catalyst with a hierarchical core-shell structure is a promising catalyst for the lithium-air battery.展开更多
Flower-like 3D CuO microspheres were synthesized and used to photo-catalyze water oxidation under visible light.The structure of the CuO microspheres was characterized by scanning electron microscopy,transmission elec...Flower-like 3D CuO microspheres were synthesized and used to photo-catalyze water oxidation under visible light.The structure of the CuO microspheres was characterized by scanning electron microscopy,transmission electron microscopy,infrared,powder X-ray diffraction,electron dispersive spectroscopy,Raman and X-ray photoelectron spectroscopy（XPS）.This is the first time that a copper oxide was demonstrated as a photocatalytic water oxidation catalyst under near neutral conditions.The catalytic activity of CuO microspheres in borate buffer shows the best performance with O2 yield of 11.5%.No change in the surface properties of CuO before and after the photocatalytic reaction was seen by XPS,which showed good catalyst stability.A photocatalytic water oxidation reaction mechanism catalyzed by the CuO microspheres was proposed.展开更多
Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike ...Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method.The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4.With a content of only 0.5 wt%carbon quantum dots,93%of Cr(VI)is reduced under visible‐light irradiation at 40 min.As a co‐catalyst,the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers,consequently enhancing the photocatalytic and photoelectrochemical activity.展开更多
Semiconductor oxides are widely used to achieve photocatalytic removal of NOx(NO and NO2) species. These materials also exhibit enhanced oxidation ability in thermally assisted photocatalysis;however, many of them ten...Semiconductor oxides are widely used to achieve photocatalytic removal of NOx(NO and NO2) species. These materials also exhibit enhanced oxidation ability in thermally assisted photocatalysis;however, many of them tend to be deactivated at high relative humidity(RH) levels. In the case of the benchmark P25 TiO2 photocatalyst, we observe a significant decrease in non-NO2 selectivity from 95.02% to 58.33% when RH increases from 20% to 80%. Interestingly, the porous TiO2(B) microspheres synthesized in this work exhibit 99% selectivity at 20% RH;the selectivity remains as high as 96.18% at 80% RH. The high humidity tolerance of the TiO2(B) sample can be ascribed to its strong water desorption capacity and easy O2 adsorption at elevated temperatures, which reflects the fact that the superoxide radical is the main active species for the deep oxidation of NOx. This work may inspire the design of efficient photothermal catalysts with application in NOx removal in hot and humid environments.展开更多
Bandgap engineering by doping and co‐catalyst loading are two primary approaches to designing efficient photocatalysts by promoting visible‐light absorption and charge separation,respectively.Shifting of the TiO2con...Bandgap engineering by doping and co‐catalyst loading are two primary approaches to designing efficient photocatalysts by promoting visible‐light absorption and charge separation,respectively.Shifting of the TiO2conduction band edge is frequently applied to increase visible‐light absorption but also lowers the reductive properties of photo‐excited electrons.Herein,we report a visible‐light‐driven photocatalyst based on valance band edge control induced by oxygen excess defects and modification with a CuxO electron transfer co‐catalyst.The CuxO grafted oxygen‐rich TiO2microspheres were prepared by ultrasonic spray pyrolysis of the peroxotitanate precursor followed by a wet chemical impregnated treatment.We found that oxygen excess defects in TiO2shifted the valence band maximum upward and improved the visible‐light absorption.The CuxO grafted onto the surface acted as a co‐catalyst that efficiently reduced oxygen molecules to active intermediates(i.e.,O2??radial and H2O2),thus consuming the photo‐generated electrons.Consequently,the CuxO grafted oxygen‐rich TiO2microspheres achieved a photocatalytic activity respectively8.6,13.0and11.0as times high as those of oxygen‐rich TiO2,normal TiO2and CuxO grafted TiO2,for degradation of gaseous acetaldehyde under visible‐light irradiation.Our results suggest that high visible‐light photocatalytic efficiency can be achieved by combining oxygen excess defects to improve visible‐light absorption together with a CuxO electron transfer co‐catalyst.These findings provide a new approach to developing efficient heterojunction photocatalysts.展开更多
To study the physical and chemical properties of aluminosilicate microsphere catalyst by impregnation and calcination us was first obtained aluminosilicate microsphere catalyst U, Nd for petrochemical processes. The m...To study the physical and chemical properties of aluminosilicate microsphere catalyst by impregnation and calcination us was first obtained aluminosilicate microsphere catalyst U, Nd for petrochemical processes. The method of X-ray structure has been studied for the microsphere catalyst U, Nd.展开更多
This paper describes the preparation and evaluation of a micro-sphere catalytic complex for the hydrogen production in a Reactive Sorption Enhanced Reforming （ReSER） process. The catalytic complex made by a spray te...This paper describes the preparation and evaluation of a micro-sphere catalytic complex for the hydrogen production in a Reactive Sorption Enhanced Reforming （ReSER） process. The catalytic complex made by a spray technique has a dual function containing Ni as a catalytic material and CaO as an adsorption material used in the ReSER process. The attrition characteristics of the catalytic complex are acceptable for the commercial used. The nano GaCO3 material used as a precursor of CaO showed a desirable durability with a CO2 sorption capacity of 0.6 mol CO2/kg after 10 repeating cycles under the carbonation temperature of 600 ℃, a CO2 partial pressure of 0.02 MPa, and a calcination temperature of 750 ℃ in N2 measured by a thermal gravimetric analyzer. The testing of the catalytic complex for ReSER showed a hydrogen yield of over 95 % （v/v） in the laboratory fixed fluidized bed reactor. The catalytic system has an attractive prospect in the ReSER process for hydrogen production, especially in the fluidized mode where reactor and regenerator combined in a cycling process.展开更多
We first obtained by impregnating of the microsphere magnetic catalyst with salts of Thorium and of Uranium and examined the X-ray thorium-uranium catalyst for Fischer-Tropsch synthesis. Introduction in catalyst addit...We first obtained by impregnating of the microsphere magnetic catalyst with salts of Thorium and of Uranium and examined the X-ray thorium-uranium catalyst for Fischer-Tropsch synthesis. Introduction in catalyst additive thorium and uranium ions and manganese improves the thermal stability of the magnetic microsphere catalyst.展开更多
Photocatalysts with desirable selectivity to transformation and purification of targeted pollutants are of great importance in water purification. Here, we demonstrate that selective photocatalysis can be realized by ...Photocatalysts with desirable selectivity to transformation and purification of targeted pollutants are of great importance in water purification. Here, we demonstrate that selective photocatalysis can be realized by the assistance of gold-enhanced selective adsorption onto carbon-coated Au/TiO2 mesoporous microspheres （Au/TiO2@C-MM）, which were prepared via a surfactant-assisted two-step method that involved the assembly of oleic acid-stabilized titania and gold nanoparticles into colloidal spheres in an emulsion using sodium dodecyl sulfate as a surfactant and the conversion of the surfactants into carbon under annealing in Ar. Due to the negatively charged amorphous carbon, the mesoporous structure, and the surface plasmon resonance absorption of the Au components, the Au/TiO2@C-MM shows enhanced charge- and size-selective adsorption prop- erties, which enables the materials to have high selectivity in the photocatalytic process.展开更多
文摘以无助剂的二氧化硅溶胶为胶液,通过离心喷雾干燥制备球径可控的微米钛硅分子筛催化剂(TS-1)微球。考察了成型过程中进料速度、喷雾成型温度等工艺参数对分子筛成球、球径以及球形度的影响,并初步探讨了成球机制。结果表明,成型温度为170℃、进料速度为8 m L/min时可制备出球形度良好、球径集中分布于55μm的钛硅分子筛微球。将其用于环己酮氨肟化反应中,在环己酮空速为12 h-1催化反应中,寿命为28 h(转化率>90%)。优异的催化性能归因于分子筛微球高的比表面积、丰富的孔结构以及微球中含硅非活性成分抑制了钛硅分子筛骨架钛流失。
基金Project(20973124)supported by the National Natural Science Foundation of ChinaProject(KLAEMC-OP201101)supported by the Open Project of Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education(Nankai University),China
文摘The hollow α-MnO2 nanoneedle-based microspheres coated with Pd nanoparticles were reported as a novel catalyst for rechargeable lithium-air batteries. The hollow microspheres are composed ofα-MnO2 nanoneedles. Pd nanoparticles are deposited on the hollow microspheres through an aqueous-solution reduction of PdCl2 with NaBH4 at room temperature. The results of TEM, XRD, and EDS show that the Pd nanoparticles are coated on the surface ofα-MnO2 nanoneedles uniformly and the mass fraction of Pd in the Pd-coated α-MnO2 catalyst is about 8.88%. Compared with the counterpart of the hollow α-MnO2 catalyst, the hollow Pd-coated α-MnO2 catalyst improves the energy conversion efficiency and the charge-discharge cycling performance of the air electrode. The initial specific discharge capacity of an air electrode composed of Super P carbon and the as-prepared Pd-coatedα-MnO2 catalyst is 1220 mA＆#183;h/g （based on the total electrode mass） at a current density of 0.1 mA/cm2, and the capacity retention rate is about 47.3% after 13 charge-discharge cycles. The results of charge-discharge cycling tests demonstrate that this novel Pd-coatedα-MnO2 catalyst with a hierarchical core-shell structure is a promising catalyst for the lithium-air battery.
基金supported by the National Natural Science Foundation of China(21173105,21172098)~~
文摘Flower-like 3D CuO microspheres were synthesized and used to photo-catalyze water oxidation under visible light.The structure of the CuO microspheres was characterized by scanning electron microscopy,transmission electron microscopy,infrared,powder X-ray diffraction,electron dispersive spectroscopy,Raman and X-ray photoelectron spectroscopy（XPS）.This is the first time that a copper oxide was demonstrated as a photocatalytic water oxidation catalyst under near neutral conditions.The catalytic activity of CuO microspheres in borate buffer shows the best performance with O2 yield of 11.5%.No change in the surface properties of CuO before and after the photocatalytic reaction was seen by XPS,which showed good catalyst stability.A photocatalytic water oxidation reaction mechanism catalyzed by the CuO microspheres was proposed.
文摘Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method.The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4.With a content of only 0.5 wt%carbon quantum dots,93%of Cr(VI)is reduced under visible‐light irradiation at 40 min.As a co‐catalyst,the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers,consequently enhancing the photocatalytic and photoelectrochemical activity.
文摘Semiconductor oxides are widely used to achieve photocatalytic removal of NOx(NO and NO2) species. These materials also exhibit enhanced oxidation ability in thermally assisted photocatalysis;however, many of them tend to be deactivated at high relative humidity(RH) levels. In the case of the benchmark P25 TiO2 photocatalyst, we observe a significant decrease in non-NO2 selectivity from 95.02% to 58.33% when RH increases from 20% to 80%. Interestingly, the porous TiO2(B) microspheres synthesized in this work exhibit 99% selectivity at 20% RH;the selectivity remains as high as 96.18% at 80% RH. The high humidity tolerance of the TiO2(B) sample can be ascribed to its strong water desorption capacity and easy O2 adsorption at elevated temperatures, which reflects the fact that the superoxide radical is the main active species for the deep oxidation of NOx. This work may inspire the design of efficient photothermal catalysts with application in NOx removal in hot and humid environments.
基金supported by the National Natural Science Foundation of China(51072032,51372036,51702235)~~
文摘Bandgap engineering by doping and co‐catalyst loading are two primary approaches to designing efficient photocatalysts by promoting visible‐light absorption and charge separation,respectively.Shifting of the TiO2conduction band edge is frequently applied to increase visible‐light absorption but also lowers the reductive properties of photo‐excited electrons.Herein,we report a visible‐light‐driven photocatalyst based on valance band edge control induced by oxygen excess defects and modification with a CuxO electron transfer co‐catalyst.The CuxO grafted oxygen‐rich TiO2microspheres were prepared by ultrasonic spray pyrolysis of the peroxotitanate precursor followed by a wet chemical impregnated treatment.We found that oxygen excess defects in TiO2shifted the valence band maximum upward and improved the visible‐light absorption.The CuxO grafted onto the surface acted as a co‐catalyst that efficiently reduced oxygen molecules to active intermediates(i.e.,O2??radial and H2O2),thus consuming the photo‐generated electrons.Consequently,the CuxO grafted oxygen‐rich TiO2microspheres achieved a photocatalytic activity respectively8.6,13.0and11.0as times high as those of oxygen‐rich TiO2,normal TiO2and CuxO grafted TiO2,for degradation of gaseous acetaldehyde under visible‐light irradiation.Our results suggest that high visible‐light photocatalytic efficiency can be achieved by combining oxygen excess defects to improve visible‐light absorption together with a CuxO electron transfer co‐catalyst.These findings provide a new approach to developing efficient heterojunction photocatalysts.
文摘To study the physical and chemical properties of aluminosilicate microsphere catalyst by impregnation and calcination us was first obtained aluminosilicate microsphere catalyst U, Nd for petrochemical processes. The method of X-ray structure has been studied for the microsphere catalyst U, Nd.
基金supports from Sinopec of China and from National Science Foundation of China (NSFC) under contracts No.20676119supports from Sinopec of China and from National Science Foundation of China (NSFC) under contracts No. 20876142 respectively
文摘This paper describes the preparation and evaluation of a micro-sphere catalytic complex for the hydrogen production in a Reactive Sorption Enhanced Reforming （ReSER） process. The catalytic complex made by a spray technique has a dual function containing Ni as a catalytic material and CaO as an adsorption material used in the ReSER process. The attrition characteristics of the catalytic complex are acceptable for the commercial used. The nano GaCO3 material used as a precursor of CaO showed a desirable durability with a CO2 sorption capacity of 0.6 mol CO2/kg after 10 repeating cycles under the carbonation temperature of 600 ℃, a CO2 partial pressure of 0.02 MPa, and a calcination temperature of 750 ℃ in N2 measured by a thermal gravimetric analyzer. The testing of the catalytic complex for ReSER showed a hydrogen yield of over 95 % （v/v） in the laboratory fixed fluidized bed reactor. The catalytic system has an attractive prospect in the ReSER process for hydrogen production, especially in the fluidized mode where reactor and regenerator combined in a cycling process.
文摘We first obtained by impregnating of the microsphere magnetic catalyst with salts of Thorium and of Uranium and examined the X-ray thorium-uranium catalyst for Fischer-Tropsch synthesis. Introduction in catalyst additive thorium and uranium ions and manganese improves the thermal stability of the magnetic microsphere catalyst.
基金supported by the National Natural Science Foundation of China (21271019 and 21641005)Beijing Engineering Center for Hierarchical Catalysts, the Fundamental Research Funds for the Central Universities (YS1406)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in the University (IRT1205)the long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of Chinathe National Program on Key Basic Research Project (2014CB932104)
文摘Photocatalysts with desirable selectivity to transformation and purification of targeted pollutants are of great importance in water purification. Here, we demonstrate that selective photocatalysis can be realized by the assistance of gold-enhanced selective adsorption onto carbon-coated Au/TiO2 mesoporous microspheres （Au/TiO2@C-MM）, which were prepared via a surfactant-assisted two-step method that involved the assembly of oleic acid-stabilized titania and gold nanoparticles into colloidal spheres in an emulsion using sodium dodecyl sulfate as a surfactant and the conversion of the surfactants into carbon under annealing in Ar. Due to the negatively charged amorphous carbon, the mesoporous structure, and the surface plasmon resonance absorption of the Au components, the Au/TiO2@C-MM shows enhanced charge- and size-selective adsorption prop- erties, which enables the materials to have high selectivity in the photocatalytic process.
