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91.
In Situ Synthesis of NaY Zeolite with Coal—Based Kaolin 总被引:3,自引:0,他引:3
XinmeiLiu ZifengYan HuaipingWang YantuoLuo 《天然气化学杂志》2003,12(1):63-73
NaY zeolites were in-situ synthesized form coal-based kaolin via the hydrothermal method. The effects of various factors on the structure of the samples were extensively investigated.The samples were characterized by N2 adsorption,XRD,IR and DTG-DTA methods,and the results show that the crystallization temperature and amount of added water play an important role in the formation of the zeolite structure.The 4A and P zeolites are the competitive Phaes present in the resulting product.However,NaY zeolites wiht a higher relative crystallinity,excluding impure crystals and the well hydrothermal stapore size distribution,and this means that optimization of this process might result in a commercial route to synthesize NaY zeolites form coal-based kaolin. 相似文献
92.
93.
蜂窝状堇青石载体Al2O3涂层的原位合成 总被引:2,自引:0,他引:2
采用改进的原位合成法(原位-浸涂法)在蜂窝状堇青石载体表面制备了多孔氧化铝涂层.着重研究了制备条件对涂层负载、晶相及其孔结构性质的影响,并与其他方法制备的涂层进行了比较.结果表明,采用多次原位合成法制备能提高氧化铝涂层的牢固度,但每次负载量偏低;原位-浸涂法适宜的制备参数为:水解温度83℃,水/异丙醇铝摩尔比60,pH值3.5~4.0,焙烧温度500℃.原位-浸涂法有利于制备Al2O3涂层,具有较好的牢固度,而且涂层的孔径分布窄,具有较大的比表面积、比孔体积和平均孔径. 相似文献
94.
Tinghua Wu Dongmin Lin Ying Wu Xiaoping Zhou Qiangu Yan Weizheng Weng Huilin Wan 《天然气化学杂志》2007,16(3):316-321
Partial oxidation of methane to syngas (POM) over Rh/SiO2 catalyst was investigated using in-situ FT-IR. When methane interacted with 1.0wt%Rh/SiO2 catalyst, it was dissociated to adsorbed hydrogen and CHx species. The adsorbed hydrogen atoms were transferred to SiO2 surface by "spill-over" and reacted with lattice oxygen to form surface -OH species. POM mechanism was investigated over Rh/SiO2 catalyst using in-situ FT-IR. It was found that CO2 was formed before CO could be detected when CH4 and O2 were introduced over the preoxidized Rh/SiO2 catalyst, whereas CO was detected before CO2 was formed over the prereduced Rh/SiO2 catalyst. 相似文献
95.
Radha Raman Mishra 《固体与材料科学评论》2016,41(3):217-255
Microwave processing of materials has emerged as a new method for processing of a variety of materials in the recent years. Microwaves have been used effectively with significant advantages, particularly in food processing and chemical synthesis. They are also found to be efficient for processing polymers, ceramics, polymeric composites, and ceramic composites. The physics of interaction of microwaves with characteristically different materials is not yet explored well; consequently, there are challenges in microwave processing of metal-based materials. Industrial processing of bulk metal is yet to be popular in spite of the fact that the feasibility of metal powder sintering was demonstrated a few decades ago. This article provides a summary of fundamental aspects of microwave processing of metal-based materials and their interaction with metallic materials. The processing challenges have been surveyed; developments in terms of techniques and tooling have been analyzed. Possible effects of microwave processing on metallic materials, in particular metal powders, bulk metals, bulk metal-metal powder systems, and sheet metals have been presented. Future research aspects of microwave processing of metallic materials with reference to metal casting have been identified. 相似文献
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97.
Shengpeng Mo Peng Peng Yinchang Pei Taiming Shen Qinglin Xie Mingli Fu Yunfa Chen Daiqi Ye 《中国化学快报》2021,32(6):2057-2060
Herein, a facile glycol reduction route is successful employed to synthesize bimetallic Pt Ag alloys with homogeneous distribution of sizes and elements. Experimental studies reveal that the ultrafine Pt Ag alloys with well-defined sizes from around 3.3 nm to 5.8 nm are immobilized onto MnO_2 microsphere,which remarkably enhances the catalytic performances for CO oxidation. Importantly, quasi in-situ X-ray photoelectron spectroscopy(XPS) result reveals that both Mn and Pt ions on the surface of catalysts would realize alternating reduction-oxidation by CO and O_2 molecules, and the oxygen vacancy sites could be replenished and excited by gas-phase O_2. 相似文献
98.
Dong-Sheng Pan Zheng-Han Guo Jin-Kun Li Sai Huang Ling-Li Zhou Prof. Dr. Jun-Ling Song 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(28):7731-7737
Transition-metal phosphates have been widely applied as promising candidates for electrochemical energy storage and conversion. In this study, we report a simple method to prepare a N, F co-doped mesoporous cobalt phosphate with rich-oxygen vacancies by in-situ pyrolysis of a Co-phosphate precursor with NH4+ cations and F− anions. Due to this heteroatom doping, it could achieve a current density of 10 mA/cm2 at lower overpotential of 276 mV and smaller Tafel slope of 57.11 mV dec−1 on glassy carbon. Moreover, it could keep 92 % of initial current density for 35 h, indicating it has an excellent stability and durability. Furthermore, the optimal material applied in supercapacitor displays specific capacitance of 206.3 F g−1 at 1 A ⋅ g−1 and maintains cycling stability with 80 % after 3000 cycles. The excellent electrochemical properties should be attributed to N, F co-doping into this Co-based phosphate, which effectively modulates its electronic structure. In addition, its amorphous structure provides more active sites; moreover, its mesoporous structure should be beneficial to mass transfer and electrolyte diffusion. 相似文献
99.
Naiku Xu Jinpeng Mo Changfa Xiao Xutong Han 《Journal of Macromolecular Science: Physics》2015,54(10):1211-1224
In this study, in-situ compatibilized polymer blends of polypropylene (PP) and poly (butyl methacrylate-co-hydroxyethyl methacrylate) P(BMA-co-HEMA) were prepared in a corotating twin screw extruder through the reactive extrusion of mixtures of PP, P(BMA-co-HEMA), butyl methacrylate, and benzoyl peroxide. In the process of reactive extrusion, butyl methacrylate and benzoyl peroxide were used as the monomer and the initiator, respectively. Thereafter the polymer blend was made into fibers via melt spinning. The miscibility of PP and P(BMA-co-HEMA) in the blend fibers was investigated using field emission scanning electron microscopy. The absorption percentage of the blend fibers for organic liquids and their remaining ratios after the absorption tests were also determined and used to prove the generation of the third phase. The changes in the fiber morphology during organic liquid absorption were observed using polarized light microscopy. In addition, the effect of the miscibility on the crystal structure and melting characteristic of the blend fibers were analyzed using wide-angle X-ray diffractometry and differential scanning calorimetry. Finally, the thermal stability of the blend fibers that was associated with the miscibility of PP and P(BMA-co-HEMA) in the blend fibers were characterized by using thermogravimetry and dynamic thermomechanical analysis. 相似文献
100.
本文利用原子力显微镜原位研究Mn79.5Fe15.6Cu4.9反铁磁高温形状记忆合金在升降温过程中与马氏体相变相关的表面起伏特征, 同时采用X射线衍射、动态热机械分析等实验检测手段辅助分析其微观组织结构演化, 从纳米尺度分析面心立方–面心四方结构相变及表面浮突产生的物理机理. 实验结果表明: 在升降温过程中观察到帐篷型表面浮突, 由面心立方–面心四方马氏体逆相变产生的, 即母相浮突, 这与通常观测到的马氏体浮突不同; 实验证实面心立方–面心四方马氏体逆相变具有切变特征, 马氏体孪晶的逆向切变是产生帐篷型表面浮突的主要机理; 测得逆孪晶切变的浮突角小于1°, 远小于传统形状记忆合金的表面浮突角值, 这是由于面心立方母相与面心四方马氏体相结构差异较小造成的; 表面浮突随温度变化具有极好的可逆性, 这是马氏体相变晶体学可逆性决定的, 表明该合金具有优良的表面形貌记忆效应. 相似文献