Zeolite FAU composites with a macro/meso-microporous hierarchical structure were hydrothermally synthesized using macro-mesoporous γ-Al_2O_3 monolith as the substrate by means of the liquid crystallization directing...Zeolite FAU composites with a macro/meso-microporous hierarchical structure were hydrothermally synthesized using macro-mesoporous γ-Al_2O_3 monolith as the substrate by means of the liquid crystallization directing agent(LCDA) induced method. No template was needed throughout the synthesis processes. The structure and porosity of zeolite composites were analyzed by means of X-ray powder diffraction(XRD), scanning electron microscopy(SEM) and N_2adsorption-desorption isotherms. The results showed that the supported zeolite composites with varied zeolitic crystalline phases and different morphologies can be obtained by adjusting the crystallization parameters, such as the crystallization temperature, the composition and the alkalinity of the precursor solution. The presence of LCDA was defined as a determinant for synthesizing the zeolite composites. The mechanisms for formation of the hierarchically porous FAU zeolite composites in the LCDA induced synthesis process were discussed. The resulting monolithic zeolite with a trimodal-porous hierarchical structure shows potential applicability where facile diffusion is required.展开更多
Metal matrix composites (MMCs) are gaining widespread recognition in numerous technological fields owing to its superior mechanical properties when compared with conventional metals/alloys. The aluminium based hybrid ...Metal matrix composites (MMCs) are gaining widespread recognition in numerous technological fields owing to its superior mechanical properties when compared with conventional metals/alloys. The aluminium based hybrid composites are increasingly being used in the transport, aerospace, marine, automobile and mineral processing industries, owing to the improved strength, stiffness and wear resistance properties. In the present research work, the composites were prepared using the liquid metallurgy technique, in which 2 - 10 weight percentage of Al2O3 particulates and 1 weight percentage of Graphite were dispersed in the base Al6061 alloy. The Casted hybrid composites were subjected to machining process to prepare the specimens according to ASTM standards. Then, the prepared specimens are subjected for assessing the Microstructure followed by its Mechanical behaviors such as, Hardness, Tensile strength, Compressive strength respectively. The microstructure analysis confirms that homogenous distribution of Al2O3 and Gr in the Al6061 matrix alloy and there was a momentous enhancement in decisive tensile strength, compressive strength and hardness properties of the hybrid composite. However, a substantial increase in the compressive strength was noticed in graphite reinforced composites as the graphite content was increased and there was a significant diminution in hardness coupled with monotonic increases in the ductility. Further, the ultimate tensile strength and compressive strength of the composite was noticed;thus the outcome of the study will provide explicit rationalizations for these observable facts. Therefore, the proposed way out in the study can provide ample of approaches to minimize the existing problem by employing this newer hybrid composites.展开更多
A new method for preparing LiLaNiO/γ(-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic pr...A new method for preparing LiLaNiO/γ(-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic properties during the 120 hours operation at atmospheric pressure were found for the catalyst. Under the high space velocity of 9.0×104l/(kg·(h)(CH4), the conversion of methane came to 95.5%, and the selectivity of carbon monoxide was not below 96.0% at 1123K when ratio of the feedstock (CH4/O2) was equal to 2.0.展开更多
Advanced technology has put an increasing demand on the composite materials, particularly more in the areas of dynamic structures. Among the several types of aluminum alloys being used, Al5000 series are widely used i...Advanced technology has put an increasing demand on the composite materials, particularly more in the areas of dynamic structures. Among the several types of aluminum alloys being used, Al5000 series are widely used in marine and aerospace applications due to their superior corrosion resistance, excellent formability and good welding characteristics. Al5083, a non-heat treatable high Mg-Al wrought alloy, is extensively used for the marine applications. Hence, an attempt has been made in the proposed work to study the effects of Graphite (Gr) and Aluminium oxide (Al2O3) on aluminum hybrid composites involving both hard and soft reinforcements on wear and corrosion properties. The synthesis of hybrid metal matrix composite used in the present study has been carried out by stir casting method. The effects of reinforcement, time duration and particle size on prepared samples of composites have been studied on slurry erosive wear. The static and accelerated corrosion tests have been performed and the microhardness of the developed composites was also investigated. The experimental results on Al5083-Al2O3-Gr hybrid composites revealed that the addition of reinforcement improves the hardness and reduces corrosion and wear rates.展开更多
TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the ...TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the active component, and inorganic oxides such as γ-alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ) and ceria-zirconia (CeO 2-ZrO 2 ) are used as the support. Interaction of precious metals and support plays an important role in the thermal stability and catalytic performance of TWCs. The support can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature. In the same, precious metals can also enhance the redox performance and oxygen storage capacity of support. This paper reviews the reaction phenomenon and mechanism of precious metals (Pt, Pd, Rh) and supports such as Al 2 O 3 , CeO 2-based composite oxides.展开更多
In recent years,development of all-solid-state batteries has become a promising approach to improve the safety of batteries.Herein,we report the preparation of a new composite polymer electrolyte (CPE)for use in all-s...In recent years,development of all-solid-state batteries has become a promising approach to improve the safety of batteries.Herein,we report the preparation of a new composite polymer electrolyte (CPE)for use in all-solid-state sodium ion batteries.The CPE comprising of poly(methacrylate)(PMA),poly(ethylene glycol)(PEG),α-Al2O3 with acidic surface sites,and NaClO4 exhibited high ionic conductivity (1.46×10^-4 S·cm^-1 at 70℃),wide electrochemical stability window (4.5V vs.Na+/Na),and good mechanical strength.With the introduction of the prepared CPE and Na3V2(PO4)3,the final all-solid-state sodium ion batteries showed good rate and cycle performance,with a high reversible capacity of 85mAh·g^-1 when operated at 0.5C (1C=118mA·g^-1)and 94.1%capacity retention rate after 350cycles at 70℃.Our work provides a novel solid electrolyte for the development of all-solid-state sodium ion batteries.展开更多
基金the financial support from the National Natural Science Foundation of China(No.20973022 and No.11472048)the State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)(Serial No.33600000-14-ZC0607-0006)
文摘Zeolite FAU composites with a macro/meso-microporous hierarchical structure were hydrothermally synthesized using macro-mesoporous γ-Al_2O_3 monolith as the substrate by means of the liquid crystallization directing agent(LCDA) induced method. No template was needed throughout the synthesis processes. The structure and porosity of zeolite composites were analyzed by means of X-ray powder diffraction(XRD), scanning electron microscopy(SEM) and N_2adsorption-desorption isotherms. The results showed that the supported zeolite composites with varied zeolitic crystalline phases and different morphologies can be obtained by adjusting the crystallization parameters, such as the crystallization temperature, the composition and the alkalinity of the precursor solution. The presence of LCDA was defined as a determinant for synthesizing the zeolite composites. The mechanisms for formation of the hierarchically porous FAU zeolite composites in the LCDA induced synthesis process were discussed. The resulting monolithic zeolite with a trimodal-porous hierarchical structure shows potential applicability where facile diffusion is required.
文摘Metal matrix composites (MMCs) are gaining widespread recognition in numerous technological fields owing to its superior mechanical properties when compared with conventional metals/alloys. The aluminium based hybrid composites are increasingly being used in the transport, aerospace, marine, automobile and mineral processing industries, owing to the improved strength, stiffness and wear resistance properties. In the present research work, the composites were prepared using the liquid metallurgy technique, in which 2 - 10 weight percentage of Al2O3 particulates and 1 weight percentage of Graphite were dispersed in the base Al6061 alloy. The Casted hybrid composites were subjected to machining process to prepare the specimens according to ASTM standards. Then, the prepared specimens are subjected for assessing the Microstructure followed by its Mechanical behaviors such as, Hardness, Tensile strength, Compressive strength respectively. The microstructure analysis confirms that homogenous distribution of Al2O3 and Gr in the Al6061 matrix alloy and there was a momentous enhancement in decisive tensile strength, compressive strength and hardness properties of the hybrid composite. However, a substantial increase in the compressive strength was noticed in graphite reinforced composites as the graphite content was increased and there was a significant diminution in hardness coupled with monotonic increases in the ductility. Further, the ultimate tensile strength and compressive strength of the composite was noticed;thus the outcome of the study will provide explicit rationalizations for these observable facts. Therefore, the proposed way out in the study can provide ample of approaches to minimize the existing problem by employing this newer hybrid composites.
基金the National Advanced Materials Committee of China (Grant No. 715-006-0122) and the Ministry of Science and Technology, China (
文摘A new method for preparing LiLaNiO/γ(-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic properties during the 120 hours operation at atmospheric pressure were found for the catalyst. Under the high space velocity of 9.0×104l/(kg·(h)(CH4), the conversion of methane came to 95.5%, and the selectivity of carbon monoxide was not below 96.0% at 1123K when ratio of the feedstock (CH4/O2) was equal to 2.0.
文摘Advanced technology has put an increasing demand on the composite materials, particularly more in the areas of dynamic structures. Among the several types of aluminum alloys being used, Al5000 series are widely used in marine and aerospace applications due to their superior corrosion resistance, excellent formability and good welding characteristics. Al5083, a non-heat treatable high Mg-Al wrought alloy, is extensively used for the marine applications. Hence, an attempt has been made in the proposed work to study the effects of Graphite (Gr) and Aluminium oxide (Al2O3) on aluminum hybrid composites involving both hard and soft reinforcements on wear and corrosion properties. The synthesis of hybrid metal matrix composite used in the present study has been carried out by stir casting method. The effects of reinforcement, time duration and particle size on prepared samples of composites have been studied on slurry erosive wear. The static and accelerated corrosion tests have been performed and the microhardness of the developed composites was also investigated. The experimental results on Al5083-Al2O3-Gr hybrid composites revealed that the addition of reinforcement improves the hardness and reduces corrosion and wear rates.
基金National Science technology Support Plan Projects"(2012BAE06B00)
文摘TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the active component, and inorganic oxides such as γ-alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ) and ceria-zirconia (CeO 2-ZrO 2 ) are used as the support. Interaction of precious metals and support plays an important role in the thermal stability and catalytic performance of TWCs. The support can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature. In the same, precious metals can also enhance the redox performance and oxygen storage capacity of support. This paper reviews the reaction phenomenon and mechanism of precious metals (Pt, Pd, Rh) and supports such as Al 2 O 3 , CeO 2-based composite oxides.
基金the National Key R&D Program (Nos.2016YFB0901502and 2016YFB0101201)the National Natural Science Foundation of China (NSFC)(No.51771094)MOE (Nos.B12015and IRT13R30),and the Fundamental Research Funds for the Central Universities.
文摘In recent years,development of all-solid-state batteries has become a promising approach to improve the safety of batteries.Herein,we report the preparation of a new composite polymer electrolyte (CPE)for use in all-solid-state sodium ion batteries.The CPE comprising of poly(methacrylate)(PMA),poly(ethylene glycol)(PEG),α-Al2O3 with acidic surface sites,and NaClO4 exhibited high ionic conductivity (1.46×10^-4 S·cm^-1 at 70℃),wide electrochemical stability window (4.5V vs.Na+/Na),and good mechanical strength.With the introduction of the prepared CPE and Na3V2(PO4)3,the final all-solid-state sodium ion batteries showed good rate and cycle performance,with a high reversible capacity of 85mAh·g^-1 when operated at 0.5C (1C=118mA·g^-1)and 94.1%capacity retention rate after 350cycles at 70℃.Our work provides a novel solid electrolyte for the development of all-solid-state sodium ion batteries.