主动式活性炭盒法测氡影响因素研究

阐述了主动式活性炭盒法测量环境空气中氡浓度时活性炭吸附效率的影响因素,采用该法对民用建筑工程验收环境空气中氡浓度的大面积多点快速测量提供可靠数据保障。     

二氧化碳沉淀法去除苯扎贝特中主要杂质

在苯扎贝特合成的后处理过程中,利用苯扎贝特及其主要杂质在酸性上的差异,在反应物的碱性水溶液中通入CO₂,将杂质从产物中沉淀去除。 以苯扎贝特的收率和含量为指标,对该纯化工艺和传统的重结晶工艺进行了比较。 结果显示,该纯化工艺可以使合格品的收率从原工艺的62.5%提高到70.9%。 该法克服了常规重结晶带来的大量溶剂消耗和产品损失,有效提高了杂质去除率,降低了分离成本。     

活性炭对丙烯酰胺单体水溶液的精制作用

活性炭对丙烯酰胺单体水溶液的精制作用李瑛＊孙文霞季鸿渐郭淑玲＊＊申花英＊＊（中国科学院长春应用化学研究所长春１３００２２）关键词丙烯酰胺，精制，活性炭１９９６－１２－１３收稿，１９９７－０６－１６修回国家“八五”攻关项目专题＊＊现在大庆油田管理局化...     

重量法测定灰岩中的二氧化碳

采用重量法对灰岩中的二氧化碳进行测定。首先用酸分解试样,在载气作用下,产生的二氧化碳被吸收液完全吸收,最后用重量法间接求出二氧化碳的含量。实验结果准确度高,矿石中的硫不干扰测定,可测定0.1%以上的二氧化碳。不经过复杂的气体净化步骤,操作准确、简单、易行,可用于灰岩中二氧化碳的测定。     

炭载肌红蛋白作生物燃料电池阴极催化剂

生物燃料电池;肌红蛋白;阴极催化剂;活性炭;氧还原     

Stability and Reactivity of the Active Assemblies in Modified Graphites Characterized by TPD and TPH

Synthetic graphites, as prepared and modified by sulphonation or acetylation, were doped by Fe-, Co-, Ni- and Ca-nitrates. Temperature Programmed Desorption (TPD) and Temperature Programmed Hydrogenation (TPH) were applied to characterize thermal stability and reactivity of the active assemblies formed on the matrix surface. The functional groups lowered the reactivity of the graphites. Thermally less stabile carboxylic groups decomposed with formation of secondary groups giving more reactive material. Fe containing as well as sulphonated graphites showed a much lower reactivity than the others. Synergistic effects of Co/Ca and Ni/Ca were confirmed in the graphite materials. This revised version was published online in July 2006 with corrections to the Cover Date.     

负载铜的活性炭用于低浓度甲硫醇的吸附

采用浸渍法制备了负载铜的木质活性炭样品,研究了负载量、灼烧温度对材料吸附低浓度甲硫醇的性能影响,研究发现负载量和灼烧温度均对材料性能有显著作用,其中最佳的灼烧温度为300℃,最佳负载量为0.7 mmol·g~(-1),采用低温氮吸附方法、X射线衍射分析(XRD)、X射线光电子能谱法(XPS)、扫描电子显微镜(SEM)和高分辨透射电镜(HRTEM)等方法对样品进行了表征和分析,从分析结果可知,材料的吸附性能和材料比表面、样品中Cu的价态及分散状况均存在一定关系。经过优化的样品对低浓度甲硫醇表现出了良好的吸附性能,其穿透时间比空白活性炭样品提高6倍以上。     

负载铜的活性炭用于低浓度甲硫醇的吸附

采用浸渍法制备了负载铜的木质活性炭样品,研究了负载量、灼烧温度对材料吸附低浓度甲硫醇的性能影响,研究发现负载量和灼烧温度均对材料性能有显著作用,其中最佳的灼烧温度为300℃,最佳负载量为0.7 mmol·g^-1,采用低温氮吸附方法、X射线衍射分析(XRD)、X射线光电子能谱法(XPS)、扫描电子显微镜(SEM)和高分辨透射电镜(HRTEM)等方法对样品进行了表征和分析,从分析结果可知,材料的吸附性能和材料比表面、样品中Cu的价态及分散状况均存在一定关系。经过优化的样品对低浓度甲硫醇表现出了良好的吸附性能,其穿透时间比空白活性炭样品提高6倍以上。     

Activation of Isocyanates and Carbon Dioxide by a Monomeric Aluminium Hydrazide as an Active Lewis Pair

The monomeric aluminium hydrazide H₁₀C₅N? N(AltBu₂)? Ad ( 4 ; Ad=adamantyl, NC₅H₁₀=piperidinyl) was obtained in high yield by hydroalumination of the corresponding hydrazone derivative 1 . Compound 4 has a strained AlN₂ heterocycle formed by a donor–acceptor bond between the β‐nitrogen atom of the hydrazide group and the aluminium atom. Opening of this bond resulted in the formation of an active Lewis pair that was able to cooperatively activate carbon dioxide or isocyanates. Insertion of the heterocumulenes into the Al? N bond selectively afforded a carbamate and two urea derivatives in high yield. In the first step, phenyl isocyanate gave the adduct 6 , which has the oxygen atom coordinated to the aluminium atom and its central carbon atom bound to the nitrogen atom of the piperidine moiety. Adduct 6 represents a reasonable intermediate state for these activation processes. The applicability of hydroaluminated compounds, such as 4 , in organic synthesis was demonstrated by the reaction with an imidoyl chloride, which gave the corresponding amidrazone derivative 9 .     

Carbon Dioxide Fixation Method for Electrosynthesis of Benzoic Acid from Chlorobenzene

Carbon dioxide fixation technique was developed as an alternative dechlorination method of chlorobenzenes.Electrolysis of chlorobenzene was carried out in a one-compartment cell fitted with an alu- minium anode and a platinum cathode.Electrolysis in N,N-dimethylformamide(DMF)solution contain- ing 0.1 M of tetrapropylammonium bromide(TPAB)at 0℃,100 ml/min of CO_2 flow rate and 120 mA/cm~2 of current density was found to be the optimum conditions of this electrocarboxylation,which gave 72% yield of benzoic acid from chlorobenzene.These conditions were then applied to 1,2-dichlorobenzene and 1,3-dichlorobenzene in order to convert them to their corresponding benzoic acids.     

Photocatalytic Characterization of TiO_2 Supported on Active Carbon

Photocatalysis on TiO2, with a promising application to the elimination of organic contaminants from air and water, has been a particularly active area1. For such application, it is important to improve the efficiency of TiO_2 photocatalysts. In the most cases, the concentration of organic contaminants in water is extremely dilute (ppm level or below) and TiO_2 itself has low adsorbabilities for them, it usually takes a long time to complete their decomposition. One of the effective ways to …     

改性活性炭负载氯化铁催化氧杂蒽衍生物的合成

制备了一种新型改性活性炭负载FeCl₃催化剂(MAC-FeCl₃),并通过红外光谱及等离子体发射光谱等技术手段对其进行了表征。 在MAC-FeCl₃催化下,β-萘酚与醛在PEG200中,于120 ℃反应60~120 min,合成了一系列氧杂蒽类衍生物,收率为79%~93%。 该方法操作简单、产率高、环境友好。 制备的催化剂性能稳定,使用4次仍保持较高活性。     

活性炭负载TiO2光催化降解1-萘胺

活性炭负载TiO2光催化降解1-萘胺;炭载TiO2光催化剂;萘胺;光催化降解     

二氧化碳和氧气的快速电化学方法联合测定

根据Ｏ２和ＣＯ２在二甲亚砜（ＤＭＳＯ）介质中Ｐｔ电极上的伏安特性，采用微电极并结构计算机控制的电位调制技术，建立了快速联合测定ＣＯ２和Ｏ２的调制电位脉冲库仑法和调制电位脉冲电流法，取得了满意的结果。一次测量时间快达４０ｍｓ。ＣＯ２检测范围０￣１０％（体积百分比）；Ｏ２检测范围不受限制。通过编程设计特定的调制电位－时间波形，可保持连续检测的长期稳定性。     

活性炭中甲烷水合物的分解动力学

在封闭体系内,在初始分解压力0.1 MPa,温度范围276～265 K之间,测定了 五组甲烷水合物在活性炭中的解动力学数据。分析了甲烷水合物在活性炭中分解的 物理过程,提出了以微分方程表达的宏观分解动力学模型。使用单步积分的吉尔（ Gear)方法解得微分方程的数值解,结合单纯形最优化方法拟合模型参数,模型计 算值与实验值符合良好。     

Oxygenates from the Electrochemical Reduction of Carbon Dioxide

Electrochemical reduction of carbon dioxide (CO₂) driven by renewable electricity to give chemicals and fuels is considered an ideal approach that can alleviate both carbon emission and energy tension stress. High‐value chemicals such as oxygenates can be effectively produced from the electroreduction of CO₂, and this is highly attractive to promote the economy and applicability of CO₂ utilization. This review focuses on recent advancements in the electrochemical reduction of CO₂ to formic acid, methanol, ethanol, acetic acid, and other oxygenates. The principles of the process, influencing factors, and typical catalysts are summarized. On the basis of the aforementioned discussions, we present future prospects for further development of the electroreduction of CO₂ to oxygenates.     

氧掺杂氮化碳纳米片的制备及其光解水制氢性能

以草酸为氧源,二聚氰胺和尿素为原料,采用两步热聚合方式合成氧掺杂氮化碳纳米片催化剂(CNO)。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)、X射线光电子能谱分析(XPS)、荧光光谱(PL)及电化学测试等技术对催化剂进行结构表征分析。在可见光照射下通过分解水制氢反应对CNO的光催化还原性能进行评价。结果表明,草酸中的O元素通过取代氮化碳三嗪环结构中N原子直接键合到sp~2杂化碳上,形成O掺杂CNO。经O掺杂改性后的氮化碳具有良好的层状堆积结构,可见光吸收性明显提高,同时禁带宽度降低。O掺杂的引入加速了光生电子-空穴对的分离和传输,能大幅度提高氮化碳的光催化分解水制氢性能,在可见光照下达88.6μmol·h~(-1),是未掺杂CN的3.91倍。     

化学镀镍法制备碳纳米管

以PdCl2为活化液,用化学镀镍法制备了具有活性中心的镀镍硅模板,通过催化裂解在镀镍硅模板上制备了碳纳米管。讨论了化学镀工艺参数对镀镍硅模板表面活性中心的尺寸和分布的影响。最佳的工艺条件为:在0.17mol·L-1的SnCl2中敏化10min,0.4g·L-1PdCl2中活化2min,50℃施镀3min所得的镍粒子活性中心的粒径为200nm~300nm。用扫描电镜观察到碳纳米管为竹节形状,直径为100nm~110nm。     

K2CO3活化煤矸石制备活性炭吸附剂

用Ｋ２ＣＯ３化学活化煤矸石制备适用于废水处理的活性炭吸附剂．考察了活化条件对产物的比表面、孔体积及灰分的影响．增加了前处理和后处理步骤以改善产物的性能．最佳条件下获得的活性炭吸附剂ＢＥＴ比表面达１２３６ｍ２／ｇ，孔体积０．６７９ｃｍ３／ｇ．所制得的吸附剂表面是疏水性的，对水溶液中的酚类污染物有良好的吸附性能．     

Highly Active and Robust Metalloporphyrin Catalysts for the Synthesis of Cyclic Carbonates from a Broad Range of Epoxides and Carbon Dioxide

Bifunctional metalloporphyrins with quaternary ammonium bromides (nucleophiles) at the meta, para, or ortho positions of meso‐phenyl groups were synthesized as catalysts for the formation of cyclic carbonates from epoxides and carbon dioxide under solvent‐free conditions. The meta‐substituted catalysts exhibited high catalytic performance, whereas the para‐ and ortho‐substituted catalysts showed moderate and low activity, respectively. DFT calculations revealed the origin of the advantage of the meta‐substituted catalyst, which could use the flexible quaternary ammonium cation at the meta position to stabilize various anionic species generated during catalysis. A zinc(II) porphyrin with eight nucleophiles at the meta positions showed very high catalytic activity (turnover number (TON)=240 000 at 120 °C, turnover frequency (TOF)=31 500 h^?1 at 170 °C) at an initial CO₂ pressure of 1.7 MPa; catalyzed the reaction even at atmospheric CO₂ pressure (balloon) at ambient temperature (20 °C); and was applicable to a broad range of substrates, including terminal and internal epoxides.