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在硝酸氧化法制备氧化锡粉体基础上,通过改进制备工艺及条件,制得高纯度高比表面积氧化锡粉体,即:在络合能力强的复合有机酸溶液中加入纯度在99.90%以上的高纯锡,形成中间共溶体;向中间共溶体中滴加硝酸和氧化剂进行凝胶化反应,得到灰白色膏状前驱体;向膏状前驱体中滴加氨水进行聚合反应,得到棕色透明液体;棕色透明液体经过滤、喷雾干燥、热处理和粉碎得到氧化锡粉体。产品质量检测结果为:产品纯度为99.90%,中位径为3.5 μm、比表面积为20.79 m2/g、表观密度为0.81 g/cm3。该工艺简单,生产周期短,成本低,易于产业化。 相似文献
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以煤为原料,采用KOH活化法制备了高比表面积活性炭,分别考察了活化温度、浸渍比和活化时间等工艺参数对活性炭吸附性能的影响;测试了高比表面积活性炭在-196℃对N2的吸附等温线、比表面积和孔径分布。结果表明,当活化工艺参数为活化温度900℃,浸渍比4,活化时间1.5 h的条件下可以制得较好的高比表面积活性炭产品,其比表面积为3135 m2·g-1,孔容为1.72 cm3·g-1,碘吸附值为2657 mg·g-1;采用扫描电子显微镜观察了高比表面积活性炭的微观结构,采用气体分析仪检测了活化过程中的尾气成分,提出了高比表面积活性炭的活化机理。 相似文献
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高比表面积二氧化钛制备研究新进展 总被引:3,自引:1,他引:2
高比表面积二氧化钛因具有性质稳定、难溶、成本低廉等优点,近年来被广泛应用于催化剂、半导体、传感材料、电子陶瓷等领域,尤其在催化剂的研制方面,二氧化钛作为新型优良的载体被众多研究者所采用.主要介绍了高比表面积二氧化钛材料的最新研究现状、基本合成机理.综述了高比表面积二氧化钛目前常用的几种液相合成方法. 相似文献
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以无机盐为原料采用溶胶-凝胶法制备了钛-硅复合氧化物(TiO2-SiO2)。利用氮气吸附-脱附法对复合氧化物进行了比表面积分析。考察了原料配比、加料方式、表面活性剂、反应温度、老化温度、老化时间、焙烧温度等因素对复合氧化物比表面积的影响。综合结果表明:当二氧化钛质量分数为22%、添加剂为十六烷基三甲基溴化铵(CTAB)、反应温度为30 ℃、老化温度为70 ℃、老化时间为1 h、焙烧温度为150 ℃时,制备的复合氧化物的比表面积为361.4 m2/g、孔容为1.18 cm3/g、平均孔径为13.0 nm。不同因素对比表面积均有一定的影响,依据规律可以实现复合氧化物比表面积的可控调变。 相似文献
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Wen-Long Huo Xiaoyan Zhang Zunlan Hu Yugu Chen Yali Wang Jinlong Yang 《Journal of the American Ceramic Society》2019,102(3):955-961
Ceramic foams with multi-scale pores and large specific surface area have received extensive attention due to their unique structure and superior properties. Considering that there are still challenges to synthesize porous ceramics with large specific surface area, a novel ceramic foam material with ultra-large specific surface area has been prepared using hollow silica mesoporous spheres (HMSSs) as building block in this work. These building blocks were made weakly hydrophobic in order to produce HMSS particle stabilized foams. The foams exhibit a uniform primary macropore structure, which is composed of a three dimensional HMSS-assembled network, via HMSS-stabilized foams. The influence of sintering temperature on the microstructure and properties of HMSS foams is investigated. The HMSS foams exhibit highest specific surface area of 1733 m2/g, attributed to the radial mesopores in HMSS shell, when sintered at between 500°C and 800°C. This specific surface area is much higher than that of existing ceramic materials. The uniform pore structure and ultra-large specific surface area make it a promising lightweight material in potential application fields, including catalyst, adsorption, fire-resistant thermal insulation, and load and control release system. 相似文献
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利用羟基氧化铁的吸附特性可以有效脱除水体中的重金属,考察在不同条件下的脱砷效果。采用浆态床脱除法进行评价实验,主要考察废液砷含量、p H、温度、羟基氧化铁浓度和震荡时间等对脱砷率的影响。结果表明,废液砷含量和p H对脱砷率影响较小,时间、温度及羟基氧化铁浓度对脱砷率影响较大,羟基氧化铁浓度为影响脱砷效果的主要因素,整体来看,脱除率较高。在羟基氧化铁浓度为150 mg·m L-1、震荡时间1 h和温度50℃条件下,可将初始砷含量176.00 mg·L-1的废水降至砷含量为5.46 mg·L-1。 相似文献
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天然气中少量乙烷和丙烷的存在会直接影响活性炭对天然气的吸附存储容量。为此,体积法测定了高比表面积活性炭对甲烷、乙烷和丙烷的吸附等温线,吸附温度分别为283,293,303和313K;采用Langmuir-Freundlich(LF)方程拟合吸附等温线,得到各气体的方程参数,进而采用LRC关联式预测多组分吸附平衡数据,并计算活性炭对模拟天然气的存储能力。结果表明:活性炭对3种气体的吸附等温线都属于I型等温线,采用L-F方程可以很好地描述各气体的吸附等温线;高比表面积活性炭对模拟天然气的存储量随吸附温度的升高而显著降低,在吸附存储压力为3.5 MPa,吸附温度从283 K上升到313 K,相应的存储量(体积比)由139降低为103;与纯甲烷的吸附存储相比,模拟天然气的吸附储量(体积比)提高约20。 相似文献
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《Ceramics International》2017,43(7):5687-5692
This study reports the fabrication and characterization of mesoporous LaNiO3/NiO composite with a very high specific surface area for a battery-type electrode. The mesoporous LaNiO3/NiO composite was synthesized via a sol–gel method by using silica gel as a template, the colloidal silica gel was obtained by the hydrolysis and polymerization of tetraethoxysilane in the presence of La and Ni salts. We investigated the structure and the electrochemical properties of mesoporous LaNiO3/NiO composite in detail. The mesoporous composite sample showed a specific surface area of 372 m2 g−1 with 92.7% mesoporous area and displayed remarkable electrochemical performance as a battery-type electrode material for supercapacitor. The specific capacity values were found to be 237.2 mAh g−1 at a current density of 1 A g−1 and 128.6 mAh g−1 at a high current density of 20 A g−1 in 1 M KOH aqueous electrolyte. More importantly, this mesoporous composite also showed an excellent cycling performance with the retention of 92.6% specific capacitance after 60,000 charging and discharging cycles. 相似文献
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《Ceramics International》2017,43(18):16043-16047
The controlled fabrication of monodisperse yttria-stabilized zirconia powders with high specific surface area (SSA) is crucial for their application performances to be bought into full play. Herein, the 3 mol% yttria stabilized zirconia (3YSZ) with ultrahigh SSA was synthesized by an one-step alkali chloride-assisted solution combustion process, employing urea as fuel and easily available ZrOCl2·8H2O as zirconium source. The effects of the alkali chloride amount/sort, urea amount and ignition temperature (Tig) on the microstructure of the resultants were systematically investigated. The results show that the 3YSZ derived from KCl-assisted solution combustion consists of monodisperse nanocrystals with 3.2 nm in average size (DTEM) and 378 m2 g−1 in SSA under the condition of stoichiometric urea-to-nitrate ratio (α = 1), 4:1 M ratio of alkali chloride to metal ions of 3YSZ (β = 4) and Tig = 500 °C. The introduction of alkali chlorides into the combustion mixture solution plays a critical part in the formation of well-dispersed 3YSZ nanocrystals with ultrahigh SSA. The amount/sort of alkali chloride, urea amount and ignition temperature also have significant influence on the SSAs of the resultants. In summary, the approach offers a facile, efficient, scalable and cost-effective strategy for fabrication of zirconia-based oxides with ultrahigh SSA. 相似文献
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《Ceramics International》2022,48(12):17261-17269
Alumina aerogel has drawn a great research interest in the aerogel community owing to its great high-temperature heat resistance. The typical preparation can be divided into two approaches depending on the type of precursors. However, the alumina aerogel derived from organic aluminum alkoxides suffers from poor monolithic integrity, whereas the one from inorganic aluminum salts presents unsatisfied thermal stability. In this work, we develop a novel organic/inorganic double-precursor cross-linking method to prepare alumina aerogels. Aluminum chloride hexahydrate is used to provide an acid condition for the hydrolysis and condensation reaction of aluminum sec-butoxide (ASB), and serves as a reactant to co-condensate with the hydrolyzed ASB to form an interpenetrating chain structure. The resulting alumina aerogel exhibits a high specific surface area (SSA) of 667 m2/g and good high-temperature thermal insulation performance. Moreover, it can still retain SSA of 224 and 105 m2/g after heating at 1000 and 1300°C, respectively. 相似文献
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This study reports on a strategy of using sol–gel and supercritical drying techniques to prepare aerocellulose monoliths with enhanced specific surface area and porosity by adding NaCl particles into the cellulose solution. The addition of 5 wt% of NaCl particles led to increased specific surface area of aerocellulose monoliths (from 114 m2/g to 205 m2/g), as well as their porosity (by ~5%). The aerocellulose monoliths prepared by adding NaCl particles achieved improved porous characteristics, lightweight, lower crystallinity, and better thermal stability, as compared to the control. This study demonstrates the effectiveness of NaCl particles to tune the surface area and the pore characteristics, which provides a facile route to achieve enhanced surface area and improved pore characteristics of aerocellulose monoliths. 相似文献
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制备条件对超高比表面积活性炭结构的影响 总被引:3,自引:0,他引:3
以石油焦为炭前驱材料、用不同试剂作为活化剂,讨论了不同活化剂对石油焦的活化作用。在以KOH为活化剂时,研究了活化条件对活性炭孔结构的影响。结果表明,强碱具有明显的活化作用,盐类试荆的活化作用很差,且KOH的活化作用远优于NaOH。在碱与碳质量比为4、800℃下活化60min制得了BET比表面积为3422m^2/g的超高比表面积活性炭(SBET≥2500m^2/g)。且碱与碳质量比越大、活化温度越高及活化时间越长,所制得活性炭中大于2nm的孔所占的比例越大。 相似文献
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Gas physisorption is an experimental technique based on equilibrium Van der Waals interactions between gas molecules and solid particles, that quantifies the specific surface area (SSA), pore size distribution (PSD), and pore volume of solids and powders. The performance of catalysts, absorbents, chromatography column materials, and polymer resins depends on these morphological properties. Here we introduce the basic principles and procedures of physical adsorption, especially nitrogen physisorption, as a guide to students and researchers unfamiliar with the field. The Brunauer‐Emmett‐Teller theory (BET) is a common approach to estimate SSA that extends the Langmuir monolayer molecular adsorption model to multilayer layers. It relies on an equilibrium adsorption isotherm, measured at the normal boiling point of the adsorbate, eg, 77 K or 87 K for N2 and Ar, respectively. Web of Science indexed 45 400 articles in 2016 and 2017 that mentioned N2 adsorption porosimetry—BET and BJH (Barrett‐Joyner‐Halenda) keywords. The VOSViewer bibliometric tool grouped these articles into four research clusters: adsorption, activated carbon in aqueous solutions for removal of heavy metal ions; synthesis of nanoparticles and composites; catalysts performance in oxidation and reduction processes; and photocatalytic degradation with TiO2. According to the literature, the accuracy of the density function theory (DFT) method is higher than with the BJH theory and it is more reliable. 相似文献
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