中间相沥青基活性炭的微观结构对电化学性能的影响

以中间相沥青(Mesophase pitch,MP)为前驱体、KOH作为活化剂,分别采用直接活化法、预炭化活化法制备出活性炭(Activated carbons,ACs).采用N2吸附法对所制ACs的比表面积、孔径分布进行分析.将所制ACs应用于电化学电容器电极材料,进行恒流充放电、循环伏安电化学分析.结果表明:电极的电化学性能不仅受活性炭比表面积、孔结构的影响,也与活性炭的微观形貌有关.其中预炭化活化法ACs颗粒具有片层结构,更有利于炭电极与电解液的浸润,提高微孔比表面积对比电容的贡献.     

超临界水和水蒸气活化制备酚醛树脂基活性炭的对比研究

采用一种新型的活化技术——超临界水活化(650℃，32Pa)和传统的水蒸气活化(800℃)来制备活性炭。用氮气吸附法表征活性炭样品的孔结构，在差热／热重分析仪上考察了原料的热失重行为，对比研究了超临界水和水蒸气活化对酚醛树脂基活性炭孔结构的影响，并探讨了酚醛树脂基炭的炭化程度对活性炭孔结构的影响。研究结果表明：(1)超临界水活化有益于中孔的发展，而水蒸气活化有益于微孔的发展。(2)炭化程度较低的酚醛树脂基炭，在较低的活化烧蚀率时就能得到高比表面积和较高中孔率的活性炭。     

二次炭化、二次活化对活性炭纤维结构的影响

采用二次炭化、二次活化的方法处理商业粘胶基活性炭纤维,遗过热处理实现对材料的改性.并用等温氮吸脱附测试、X射线衍射(XRD)、扫描电子显微镜(SEM)等分析方法对样品材料进行了测试.实验结果表明制备的材料孔结构扩宽,比表面积增大,吸附性能增强.     

通过再活化浸渍金属盐的活性炭来发展中孔结构

研究了在椰子壳活性炭上浸渍金属盐（硝酸铁和硫酸铁）后，在二氧化碳气氛中催化活化对中孔结构的影响。发现硝酸铁对活性炭比表面积（-1930m^2／g）的增加和中孔结构（-10nm）的发展更有效。改性活性炭具有发达的中孔结构，显示了更大的维生素B12吸附容量（是改性前的5倍～8倍）和更快的吸附速度。中孔结构的发展基于三个方面的原因：（1）在活化过程中，浸渍在活性炭微孔内的金属盐分解所释放的氧化性气体与微孔碳壁反应，扩大了孔径；（2）在高温下，来自于金属盐的金属氧化物被碳还原，扩大了孔径；（3）在金属铁存在下，碳壁被催化活化，大大提高了活性炭的中孔率。由此提供了一种廉价的从商业活性炭制备中孔活性炭的有效途径。     

塑料热解物在城市有机废弃物制备活性炭中的作用

研究了在锯木屑、纸张和塑料的热解物为原料制备中孔活性炭过程中塑料热解物所起的作用。结果表明：在料条制备过程中，塑料热解物具有润滑、粘结作用，可有效地减少焦油粘结剂的用量；在料条炭化阶段，由于塑料热解物的热解、析出，使炭化料条具有发达的孔隙（闭合）结构，最终使在随后的活化过程加快活化反应速度，提高活性炭的吸附性能；塑料热解物在活性炭孔结构的形成和发展过程中，具有一定的调节作用。     

炭化温度对CO2活化PAN基活性炭纤维微结构的影响

将PAN坝氧化纤维在400℃～900℃炭化，经CO2活化得到一系列活性炭纤维，表征了其比表面、孔容和孔径分布等微结构参数，研究了炭化温度对CO2活化PAN基活性炭纤维微结构的影响。结果表明，炭化温度对活性炭纤维的比表面和孔结构有显著影响，适中的炭化温度（600℃）有利于得到高比表面积、大的孔容和孔径。     

多孔活性炭孔径调控研究现状

随着活性炭在各个领域的广泛应用,对其孔结构的要求越来越高,孔结构的调控成为研究热点和难点。主要综述了目前国内外关于活性炭孔径调控技术的研究进展,分别介绍了微孔、中孔和大孔调控孔结构方面的研究成果及指出了不同调控技术的优缺点,重点介绍模板法、物理-化学联合活化法、催化活化法对孔结构调控的研究,并对孔径调控技术的发展进行展望。     

太西无烟煤制备微孔活性炭的试验研究

研究了在硝酸盐与含钾化合物两种添加剂作用下用太西无烟煤制备微孔活性炭的试验条件。其制备工艺为经粉磨的原料煤和添加剂混捏挤条，然后炭化和活化。在试验中利用正交试验法，选定两种添加剂比例、炭化升温速度、活化温度、活化时间作为考查的四个因素，微孔孔容作为考查指标，得出了最佳水平组合：添加剂硝酸盐与含钾化合物的质量比为2：1，炭化升温速度5℃／min，活化温度920℃，活化时间3．5h。用氮气吸附法对活性炭产品进行分析，并用BET法、D-R方程和密度函数理论(DFT)表征了活性炭产品的比表面、总孔容、微孔孔容和孔径分布等性能指标。并对添加质量分数为6％的添加剂和无添加剂，其余因素取最佳水平值制得的活性炭产品用DFT法进行了孔径分布分析。结果表明，相同条件下添加质量分数为6％的添加剂制得的活性炭在微孔孔容和总孔容方面都有较大的提高：微孔孔容从0．1847mL／g提高到0．3299mL／g，总孔容从0．2186mL／g提高到0．5128mL／g。     

活化条件对酚醛基活性炭布结构及其电化学性能的影响

以实验室自制的酚醛基纤维布为原料,通过水蒸气活化制备了系列酚醛基活性炭布(ACCs),利用低温N_2(77K)吸附法测定了所制活性炭布的孔结构,将所制备的活性炭布用做超级电容器电极材料,用恒流充放电法和交流阻抗技术考察了所制模拟电容器的电化学性能(电解液:1M(CH_2CH_3)_3CH_3NBF_4/PC).结果表明:随着活化温度的升高或活化时间的延长,所制活性炭布的比表面积和平均孔径增大,中孔比表面积也得到明显提高.活性炭布的比电容随着比表面积的增加而增大,其中950℃活化90min的样品在50mA·g~(-1)电流密度下的比电容达到158F·g~(-1).电容保持率(C_(500)/C_(50))随着样品中孔比表面积的增加而增大,900℃活化120min的样品的电容保持率达到91.1%;随着平均孔径的增大,表征电极导电性的参数IR降减小.     

NaOH活化法制备高比表面积稻壳活性炭

以农业废弃物稻壳为原料,NaOH为活化剂,制备了中孔发达的高比表面活性炭,研究了碱炭比、活化温度对样品碘吸附值和亚甲基蓝吸附值的影响;采用SEM、TEM表征了活性炭的形貌,通过BET法计算了活性炭的比表面积,BJH方程计算出活性炭的孔径分布.结果表明,在碱炭比为3∶1、活化温度为750℃的工艺条件下制备的稻壳活性炭同时具有较高的碘吸附值和亚甲基蓝吸附值;稻壳活性炭比表面积高达2164m2/g,中孔含量达到63.67%,总孔容达到1.544mL/g.     

Effects of activation agents and intrinsic minerals on pore development in activated carbons derived from a Canadian peat

Activated carbons (ACs) with very high specific surface areas up to approximately 900 m²/g and total pore volume up to 0.5 cm³/g were produced from a Canadian peat through chemical activation using either H₃PO₄ or ZnCl₂ as the activation agent, followed by activation/carbonization in air at 450 °C for 45 min. ZnCl₂ was found to be more effective for developing microporous structures in the ACs, while H₃PO₄ is more efficient in developing the mesopores. Demineralization of the AC precursor to remove intrinsic minerals greatly affected the development of pore structures during the activation process. The AC derived from the demineralized peat activated by ZnCl₂ attained the highest BET surface area with significantly increased micro-/mesopores.     

The control of porosity at nano scale in resorcinol formaldehyde carbon aerogels

Organic aerogels were synthesized by sol–gel polymerization of resorcinol (R) with formaldehyde (F) catalyzed by sodium carbonate (C) followed by vacuum drying. The influence of the resorcinol/sodium carbonate ratio (R/C) on the porous structure of the resultant aerogels was investigated. The nitrogen adsorption–desorption measurements show that the aerogels possess a well developed porous structure and mesoporosity was found to increase with increasing the R/C ratio. Carbon aerogels were obtained by carbonization of RF aerogels. The carbonization temperature impacts the microstructure of the aerogels by pore transformations during carbonization probably due to the formation of micropores and shrinkage of the gel structure. The results showed that a temperature of 1073 K is more effective in the development of the pore structure of the gel. Activated carbon aerogels were obtained from the CO₂ activation of carbon aerogels. Activation results in an increase in the number of both micropores and mesopores, indicative of pore creation in the structure of the carbon. Activation at higher temperatures results in a higher degree of burn off and increases the pore volume and the surface area remarkably without change of the basic porous structure, pore size, and pore size distribution.     

活性炭对扑热息痛的吸附行为和体外释放性能

主要研究了药用颗粒活性炭对扑热息痛的吸附行为和体外释放性能。采用N2吸附表征了三种活性炭的孔结构，借助Beohm滴定法和质量滴定法测定了活性炭的表面含氧官能团和零电荷点pHPZC；考察了比表面积、孔隙结构与吸附性能和体外释放性能的关系，及活性炭表面化学性质对吸附性能的影响。结果表明：活性炭的孔结构和表面化学性质对吸附性能和体外释放性能具有决定性的影响。比表面积高、孔隙发达、孔径分布集中在2nm-11m,之间的中孔型活性炭，对扑热息痛的吸附力很强，平衡吸附量达到了358mg／g，累计释放率为7％；具有广谱孔径分布的活性炭，平衡吸附量为281mg／g，可以缓释12h以上，累计释放率达到27％。活性炭表面的酸性含氧官能团对吸附扑热息痛具有一定的促进作用。三种活性炭的释药过程均符合Higuchi方程释药模式。     

磷酸法活化煤焦油渣制备活性炭研究

研究了以陕西煤焦油渣作为原料,用磷酸作为活化剂,在400～1000℃的条件下经一步炭活化法制备活性炭。研究了炭活化温度、时间、料剂比对煤焦油渣制备活性炭吸附性能及孔结构的影响。实验结果表明炭活化温度、炭活化时间主要影响活性炭产品的得率,高温和长时间会导致更多的碳损失;活性炭的吸附性能及孔结构主要受炭活化温度和料剂比影响。最佳活化工艺条件为850℃、3h、1∶3。通过其活性炭表面孔径分布及表面官能团含量变化表征,用磷酸浸泡煤焦油渣制备活性炭有利于大、中孔结构的产生,其最佳活化条件下孔径分布约在20～100nm。     

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%.     

Synthesis and characterization of bimodal rod-like mesoporous carbons from raffinose by SBA-15 templates

Mesoporous carbons with bimodal rod-like pore structures and tunable pore sizes from 3.66 to 5.42 nm were for the first time obtained by employing SBA-15 as templates and raffinose as carbon precursors. Small angle X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N₂ sorption analysis, and Raman spectroscopy were used to determine the textural properties of the resulting materials. Bimodal frameworks with mesopores (4–5 nm) as well as macropores (125–130 nm) were achieved. The mesoporous carbons lost its ordered structure from the templates due to mesostructural shrinkage and collapse of mesopores, which resulted in partial duplicate of the template and pore-widening effect (meso to macropores). With the increasing of carbonization temperature from 500, 700 to 900 °C, the textural parameters such as specific surface areas, pore volumes, and mean pore diameters all increased significantly. In the temperature range studied, higher carbonization temperature would generate much more abundant porosity. The ratio of I _D to I _G (I _D/I _G) indicated a rather low crystallinity with the varying of aging temperature and the carbonization temperatures. The advantage of the procedure was that no acid or other chemical catalysts were involved during the infiltration and carbon formation process.     

Mesoporous activated carbon as electrode for electric double layer capacitor

Mesoporous activated carbon with high surface area (AC-Y-A) was prepared by carbonization followed by activation of vinylidene chloride copolymer containing yttrium acetylacetonate. Their performances as electrodes for electric double layer capacitor (EDLC) in tetraalkylammonium tetrafluoroborate (R₄NBF₄)/propylene carbonate (PC) or acetonitrile (AN) solutions were evaluated and compared with those of microporous activated carbons [AC and AC(CO₂)]. The specific EDLC capacitances of the mesoporous AC-Y-A are almost the same as those of microporous AC at low discharge current. However, at high discharge current, the specific capacitance of AC-Y-A is much higher than those of both AC and AC(CO₂) in PC and AN solutions. The capacitances decreased with increasing alkyl chain length of R₄ N⁺ ions and discharge current. These results suggest that EDLC capacitance depends on pore size of activated carbons and smooth movement of R₄ N⁺ ions in pores.     

聚偏二氯乙烯基炭用作高功率EDLC电极材料

在600℃～1100℃对聚偏二氯乙烯(PVDC)树脂仅进行炭化处理,制备了一系列PVDC基活性炭.由TG、XRD和N_2吸附等温线(77 K)分别测定了PVDC基炭经历的热解过程与其晶型、比表面积和孔结构;采用循环伏安、交流阻抗和恒电流充放电考察了它们在质量分数30%的 KOH水溶液中的电容特性.结果表明:PVDC基炭属于无定形碳,其大的比表面积(874.5m~2/g～969.2m~2/g)和丰富的微孔在固相炭化过程中形成;PVDC基炭具有适于双电层形成的优异孔径分布、高的质量比电容和面积比电容;900℃炭化的PVDC基炭具有最高的比电容值和良好的功率特性,50mA/g电流密度时的放电比电容达256.9F/g,5000mA/g电流密度时的放电比电容保持率达76.5%;提高炭化温度可提高PVDC基炭的电导率,降低电解质离子在孔内的扩散阻抗,改善双电层电容器的功率性能.