Preparation and characterization of cerium oxide templated from activated carbon

The application of carbon templating to the preparation of cerium oxide and cerium–zirconium mixed oxide was investigated. Impregnation of a highly mesoporous activated carbon (Darco KB-B) with aqueous cerium nitrate, followed by calcination to remove the template, afforded nanocrystalline ceria with a surface area of up to 148 m²/g. Ceria-zirconia with surface area of 148 m²/g was similarly prepared. TEM studies on the ceria product revealed the presence of a polycrystalline phase, comprised of irregular aggregates of ceria crystallites of ca. 6.5 nm diameter. Use of activated carbon fibers (ACFs) as templates afforded ceria with a gross morphology resembling that of the fiber template. The lower surface areas (3–59 m²/g) of the resulting ceria reflect the mainly microporous nature of the ACFs; evidently the Ce nitrate solution is largely unable to penetrate the micropores. TEM showed the ceria fibers to be comprised of crystallites possessing a morphology similar to the Darco KB-B templated ceria.     

柑橘皮中孔活性炭的制备及性能表征

以柑橘皮为原料,以氯化锌为活化剂,采用一步炭化法制备了中孔活性炭.研究了浸渍比、炭化温度及保温时间对孔结构的影响,通过BET、D-R方程、BJH方程及Kelvin理论表征了活性炭的孔结构,采用红外光谱分析样品的表面官能团,透射电镜观察微观形貌.柑橘皮中孔活性炭的适宜制备条件为:活化剂漫渍比3:1,炭化温度550℃,保温时间1h;所得活性炭中孔容积1.438cm3/g,中孔率占68.5%,BET比表面积为1476m2/g;该活性炭孔径分布集中,平均孔径3.88nm.利用中孔活性炭吸附垃圾渗滤液生化尾水,UV254值和TOC去除率分别为94.7%、66.4%.3DEEM证明该活性炭对DOM中的类富里酸具有良好的吸附性能,紫外区类和可见区类富里酸荧光强度分别降低49.1%、81.6%.     

废触媒再生制备ZnO/活性炭复合材料及表征

以醋酸乙烯合成用废触媒为原料,在分析其热解特性的基础上,提出了直接加热水蒸汽活化再生新工艺,得到了不同再生温度条件下的再生样品.采用N2吸附、碘吸附法等手段对样品的结构和吸附性能进行了表征,当废触媒在950℃处理40min时,所得样品的比表面积可达到1193m2/g,碘吸附值1080mg/g;同时采用XRD、SEM、FTIR对样品的结构和表面性质进行了分析,发现样品由活性炭(AC)和ZnO组成,且ZnO分散在AC中,表明再生的样品为ZnO/AC复合材料.新工艺为废触媒的综合利用开辟了新的途径,为ZnO/AC复合材料探索出了新的原料来源争制备方法.     

ZnCl2活化茄子秸秆制备活性炭及表征

以茄子秸秆为原料、ZnCl2为活化剂制备活性炭。通过正交实验方法确定了制备活性炭的最佳工艺条件,采用低温氮气吸附、BET、Langmuir和BJH理论对其孔结构进行了表征,利用红外光谱分析样品的表面官能团,扫描电镜观察表面形貌。结果表明以茄杆活性炭的最佳工艺条件:浸渍比为2,浸渍时间为8h,活化温度为550℃,活化时间为60min,所得的活性炭的碘吸附值为1270.06mg/g,亚甲基蓝吸附值为17.4mL/g;BET和Langmuir比表面积分别为1649.615和1851.649m2/g,吸附总孔容为0.488cm3/g,吸附平均孔径为2.241nm。     

超高比表面积活性炭的制备与表征

以无患子残渣为原料,KOH与K2CO3作为活化剂,采用微波炭化和活化两步法制备超高比表面积活性炭,通过正交实验优化活性炭的制备工艺,探讨了碱炭比、活化温度和活化时间对活性炭吸附亚甲基蓝吸附值的影响。利用N2吸脱附实验、XRD、FT-IR等实验技术,对制备的活性炭结构与性能进行了表征。结果表明,在碱炭质量比为4∶1、活化温度800℃、活化时间30 min的条件下,所制备的活性炭对亚甲基蓝吸附值为595 mg/g,BET比表面积为3 479 m2/g,吸附累积总孔容达1.8262 cm3/g,平均孔径为2.0997 nm。     

ZnCl_2活化红枣核制备多微孔活性炭及表征

以红枣核为原料,采用ZnCl2活化法,研究了活化温度、活化时间以及浸渍比等工艺参数对活性炭结构性能与表面化学性能的影响。采用低温N2吸附-脱附以及元素分析对活性炭结构进行表征,采用Boehm滴定、pHZPG、FT-IR等手段对活性炭表面性能进行表征。研究结果表明,当浸渍比为0.8,活化温度为700℃,活化时间为60 min时,活性炭的微孔结构较发达,活性炭BET比表面积为1 031 m2/g,总孔体积为0.504 cm3/g,平均孔径为1.95 nm,零电荷点(p HZPG)为7.01,活性炭的收率为41.6%。     

KOH活化法高比表面积竹质活性炭的制备与表征

以竹屑为原料,研究了KOH活化法高比表面积活性炭的制备工艺.分别考察了浸渍比、活化温度、活化时间等工艺参数对产品吸附性能的影响,并提出了可能的活化机理.在所研究的实验条件下,最佳的制备工艺是浸渍比1.0,活化温度800℃,活化时间2h.所得到的活性炭产品的比表面积和孔容可达2996m2/g和1.64cm3/g.该产品附加值高,在吸附领域特别是在双电层电容器的电极材料领域有广阔的应用前景.     

椰壳纤维基高比表面积中孔活性炭的制备

以椰壳纤维为原料,制备高比表面积中孔活性炭.采用正交试验设计实验方案,研究KOH和NaOH复合活化法制备活性炭的实验方案与工艺条件.考察了活化剂配比、炭化温度、活化温度、时间和升温速率对所制活性炭吸附性能的影响.在最佳工艺条件下,所制活性炭的比表面积达到2032m2/g,中孔发达,特别是2nm～4nm的,中孔比例达到28%.活性炭对的碘吸附值为1435mg/g,亚甲基蓝吸附值为495mg/g,产率为49%.     

活性炭模板法制备锡酸锌掺杂磷化合物及表征

选用磷酸活化后的活性炭为模板,NaSnO₃·3H₂O、ZnSO₄·7H₂O为原料,通过生物质模板法制备了锡酸锌掺杂磷(Zn₂SnO₄/P)化合物。通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)和N_2吸脱附等温线对制备的Zn₂SnO₄/P的结构、形貌进行表征。结果表明:Zn₂SnO₄/P为尖晶石结构,其形貌基本上和活性炭相匹配。其比表面积、孔体积和平均孔径分别为87m²/g、0.20cm³/g和9.0nm。     

BDAF-PMDA型聚酰亚胺炭膜的制备及其气体分离性能的研究

以2,2-双[4-(4-氨基苯氧基苯基)]六氟丙烷(BDAF)为二胺单体,均苯四酸二酐(PMDA)为二酐单体,采用两步法制备了BDAF-PMDA型聚酰亚胺,进一步高温热解制备炭膜.采用红外、热重、X射线衍射分析其结构变化,并测试炭膜对纯组分及混合气体的渗透性能和分离选择性.结果表明,BDAF-PMDA型炭膜具有较高的气体渗透性,在CO2/H2体系中可优先渗透CO2.提高炭化温度,炭膜孔径减小,气体的渗透性能降低,选择性提高,并使得BDAF-PMDA型炭膜的分离机理由表面扩散为主逐渐变为表面扩散和分子筛分共同控制.     

KOH/NaOH活化法辣椒秸秆制备高表面积活性炭与表征

以废弃辣椒秸秆为原料,KOH/NaOH为活化剂,采用正交试验,研究了活化温度、时间、炭化温度及KOH/NaOH/C对吸附性能的影响,得出最佳工艺条件即活化温度为700℃、活化时间为80min、炭化温度为450℃、KOH/NaOH/C为3∶1∶1。此条件下制得的样品Langmuir比表面积高达3217.237m2/g,吸附平均孔径为3.590nm,皆高于单一KOH活化样品(SLangmuir=3159.200m2/g,D=2.672nm)。同时采用SEM和FT-IR对KOH/NaOH活化样品的表面形貌和官能团进行分析,并与单一KOH活化样品进行对照,发现它们的化学组成相似,并皆具有丰富和发达的孔隙结构,但KOH/NaOH活化样品出现更多的中孔和一定量的大孔。     

Preparation and characterization of CeO2 highly dispersed on activated carbon

A new material constituted by cerium dioxide highly dispersed on activated carbon (CeO₂/AC) was prepared by an impregnation method using cerium(III) nitrate as CeO₂ precursor. In order to evaluate the degree of ceria dispersion on the carbon support, CeO₂/AC was characterized by a number of techniques: thermogravimetry coupled with a mass spectrometer (TG-MS), N₂ adsorption at 77 K, temperature-programmed desorption (TPD), temperature-programmed reduction (TPR) and transmission electron microscopy (TEM). The analysis of the decomposition process under inert atmosphere indicated that cerium nitrate decomposes at 440-460 K, with the evolution of NO. Furthermore, this process produces an additional oxidation of the carbon surface (with evolution of N₂O) and the subsequent onset of new oxygen surface groups, detected by means of temperature-programmed desorption. The ceria deposition process takes place with a decrease in the N₂ adsorption capacity of the starting carbon support, and the analysis of the pore size distribution showed that the majority of ceria particles are situated at the most internal part of the carbon porosity. The temperature-programmed reduction profile of CeO₂/AC was very different to that shown by unsupported CeO₂, with only one continuous reduction process at low temperatures (800-900 K). Finally, TEM pictures gave direct evidence that ceria is highly dispersed on the carbon surface, with a narrow CeO₂ particle distribution centred around 3 nm.     

Preparation of mesoporous carbon from biomass for heavy metal ion adsorption

Mesoporous carbon (MC-S) has been synthesized via a facile hydrothermal method by using cheap and nontoxic soluble starch as carbon precursor, Pluronic copolymer as soft templates. In the process of hydrothermal synthesis, the soluble starch can hydrolyze to give glucose, which can assemble with Pluronic copolymer through hydrogen bond interactions. Glucose further dehydrates and cross-links to form polymer networks. After carbonization of the polymer networks, MC-S can finally be obtained. The obtained MC-S has a specific surface area of 439 m² g^?1, uniform pore size of 4.5 nm as well as high oxygen content of 23.32%. The MC-S exhibits a good adsorption for heavy metal ions superior to FDU-15 due to the oxygen functional groups.     

Removal of phenol from aqueous solutions by adsorption onto activated carbon prepared from biomass material

Activated carbon derived from rattan sawdust (ACR) was evaluated for its ability to remove phenol from an aqueous solution in a batch process. Equilibrium studies were conducted in the range of 25–200 mg/L initial phenol concentrations, 3–10 solution pH and at temperature of 30 °C. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. Equilibrium data fitted well to the Langmuir model with a maximum adsorption capacity of 149.25 mg/g. The dimensionless separation factor R_L revealed the favorable nature of the isotherm of the phenol-activated carbon system. The pseudo-second-order kinetic model best described the adsorption process. The results proved that the prepared activated carbon was an effective adsorbent for removal of phenol from aqueous solution.     

超级电容器用活性炭的制备与电化学表征

以煤焦油沥青为前驱体,采用化学活化法制备了超级电容器用高比表面活性炭和活性炭电极.考察了活化温度对活性炭电极比电容量的影响,研究了活性炭材料的比表面积和孔结构与活性炭电极的充放电性能之间的关系,并对活性碳电极进行了电化学表征.结果表明,在500～700℃,随着活化温度的提高,活性炭电极的比电容量显著增大,当活化温度超过700℃时,活性炭电极材料的比电容量变化不明显.700℃活化温度下所制备的活性炭材料呈现明显的多孔结构,孔容为1.038cm3/g,比表面积为1959m2/g;所制成的活性炭电极比电容量为210F/g,等效内阻为0.9Ω/cm2,10mA/cm2充放电500次后保持90%以上电容量,交流阻抗谱在频率低于转化点时表现出纯粹的电容行为,循环伏安曲线显示出良好的可逆特性.     

酚醛树脂基磁性活性炭的制备及性能研究

以酚醛树脂为原料、二茂铁作为添加剂,制备了磁性活性炭(magnetic activated carbon,MAC),并采用气体吸附、液相吸附和振动磁强仪等方法表征了活性炭的孔结构、吸附能力和磁特性.此外,对磁性活性炭制备过程中的二茂铁添加量、活化时间等主要工艺参数进行了研究和初步优化.结果表明,二茂铁对活性炭孔隙的产生...     

Experimental and modelling studies of carbon dioxide adsorption by porous biomass derived activated carbon

The goal of the study was to produce a low-cost activated carbon from agricultural residues via single stage carbon dioxide (CO₂) activation and to investigate its applicability in capturing CO₂ flue gas. The performance of the activated carbon was characterized in terms of the chemical composition, surface morphology as well as textural characteristics. The adsorption capacity was investigated at three temperatures of 25, 50 and 100 °C for different types of adsorbate, such as purified carbon dioxide and binary mixture of carbon dioxide and nitrogen. The purified CO₂ adsorption study showed that the greatest adsorption capacity of the optimized activated carbon of 1.79 mmol g^?1 was obtained at the lowest operating temperature. In addition, the adsorption study proved that the adsorption capacity for binary mixtures was lower due to the reduction in partial pressure. The experimental values of the purified CO₂ adsorption were modelled by the Lagergren pseudo-first-order model, pseudo-second-order model, and intra-particle diffusion model. Based on the analysis, it inferred that the adsorption of CO₂ followed the pseudo-second-order model with regression coefficient value higher than 0.995. In addition, the adsorption study was governed by both film diffusion and intra-particle diffusion. The activation energy that was lesser than 25 kJ mol^?1 implied that physical adsorption (physisorption) occurred.     

椰壳活性炭去除染料的应用研究

本文以农业废弃物椰壳为原材料,采用化学活化法制备生物炭-椰壳活性炭,利用椰壳活性炭作为吸附剂吸附去除水中阴离子染料刚果红和阳离子染料孔雀石绿,同时考察了不同因素对去除效果的影响以及最大吸附容量。结果表明:椰壳活性炭对刚果红和孔雀石绿都有很好的去除效果,去除率可达93.2%和96.5%,吸附容量可达228.1mg/g和258.6mg/g。     

Superior capacitive behavior of porous activated carbon tubes derived from biomass waste-cotonier strobili fibers

As supercapacitor electrode materials, the sustainable biomass-derived activated carbons have attracted a great deal of attentions due to their low-cost, abundant, and unwanted natural wastes. In this work, a facile KOH activation method is adopted to prepare activated carbon tubes from the biomass waste-cotonier strobili fibers for the first time. The resultant PTAC-x materials possess highly accessible surface areas and abundant micro-mesopores, which benefit large ion storage and high-rate ion transfer. The optimized material denoted as PTAC-6 demonstrates a high specific capacity (346.1?F?g^?1 at 1?A?g^?1) and a superior rate performance (214.5?F?g^?1 at 50?A?g^?1) in the three-electrode supercapacitors. In addition, the symmetric supercapacitor exhibits excellent cycling stability with a capacitance retention of 84.21% and a columbic efficiency of nearly 100% after 10,000 cycles. Furthermore, the PTAC-6-based symmetric supercapacitor gives a remarkable specific energy of 33.04?Wh?kg^?1 at 160?W?kg^?1. Meanwhile, our proposed porous activated carbon tubes provide a green and low-cost electrode material for high-performance supercapacitors.