共查询到19条相似文献,搜索用时 120 毫秒
1.
硅钨钼酸掺杂聚苯胺催化合成环己酮1,2-丙二醇缩酮 总被引:3,自引:0,他引:3
首次采用浸渍法制备了硅钨钼酸掺杂聚苯胺催化剂H4SiW6Mo6O40/PAn。以环己酮和1,2.丙二醇为原料合成环己酮1,2-丙二醇缩酮。探讨了硅钨钼酸掺杂聚苯胺催化剂对缩酮反应的催化活性,较系统地研究了原料量比,催化剂用量,反应时间诸因素对产品收率的影响。实验表明:硅钨钼酸掺杂聚苯胺是合成环己酮1,2-丙二醇缩酮的良好催化剂,在n(环己酮):n(1,2-丙二醇)=1:1.7,催化剂用量为反应物料总质量的1.0%,环己烷为带水剂,反应时间1.0h的优化条件下,环己酮1.2-丙二醇缩酮的收率可达84.6%。 相似文献
2.
Co取代介孔磷铝分子筛的合成、表征及催化性能 总被引:1,自引:0,他引:1
以十六烷基三甲基氯化铵为模板剂,在碱性条件下采用水热晶化法合成Co取代介孔磷铝分子筛.研究溶剂种类和用量、反应温度、反应时间、催化剂用量以及H_2O_2和苯乙烯摩尔比等因素对反应的影响.催化性能测试表明:该分子筛在苯乙烯氧化制苯甲醛反应中有很好的活性,以乙腈为溶剂,当H_2O_2和苯乙烯摩尔比为3、催化剂用量为5%时,在70 ℃反应4 h后,苯乙烯的转化率为42.2%,苯甲醛的选择性为82.0%,苯甲醛产率达到34.6%. 相似文献
3.
钛酸丁酯作为前驱体,Span80、Span85和TritonX-114作为模板剂合成介孔二氧化钛,以氮吸脱附方法表征材料织构特性,以光催化丙酮研究材料孔结构对光催化性能的影响。结果表明,模板剂用量和种类对孔结构和光催化性能有较大的影响。直通孔道结构的二氧化钛比狭缝或墨水瓶孔道的二氧化钛具有更好的光催化活性,大的比表面积和孔径也有利于光活性的提高。 相似文献
4.
采用前驱体分解法制备了高纯ZrWMoO8粉体。为获得ZrWMoO8/Cu复合材料,首先将ZrWMoO8与Cu按1:1的比例进行研磨获得混合粉,采用化学镀的方法获得ZrWMoO8与Cu比例为1:1的包覆粉,然后压片并在氩气气氛保护下于500℃烧结3 h获得复合材料。详细研究了复合材料的热膨胀性能并且发现包覆粉更适合制备ZrWMoO8/Cu复合材料。结果表明:烧结后,混粉制备的复合材料中部分ZrWMoO8发生了分解并且与Cu发生了反应,而以包覆粉制备的ZrWMoO8/Cu复合材料未检测出ZrWMoO8的分解产物。包覆粉制备的复合材料在25~250℃显示的热膨胀系数为3.3774×10-6℃-1,其相对密度达到90.6%。 相似文献
5.
简要介绍了我厂生产的超低磷、硫钢如泵体材料 CK35 ,压力容器用钢 CF- 6 2及核电用钢2 0 HR的冶炼实践 ,阐述了在常规设备条件下生产高纯度钢的可能性。 相似文献
6.
7.
以钛酸四丁酯为原料,采用水解-沉淀法制备TiO2纳米粉体,利用BET、XRD、IR、SEM和激光粒度分析仪等测试手段对制备TiO2粉体晶粒大小、粉体的粒度分布情况等进行了研究,并讨论原料配比,烧成温度,pH值与晶粒大小,物相组成等之间的关系。结果表明:在600°C到800°C之间,TiO2粉体由锐态矿转变为金红石,经800°C加热2h的物相主要为金红石,粉体呈类球形;pH为3.03,n(H2O):n[Ti(C4H9O)4]=30,400°C热处理2h后制备的TiO2粉末晶粒平均尺寸为80nm,粉体的平均粒度为580nm,比表面积为117.2631m2/g。 相似文献
8.
应用尿素热解法合成晶相单一、结晶度较好的Ni(HCO3)2多孔材料,借助多种表征手段对其物化性能进行表征。N2吸附-脱附结果表明Ni(HCO3)2多孔材料有99.03 m3/g的比表面积、7.8 nm左右的孔径;扫描电镜(SEM)和粒度分布结果说明Ni(HCO3)2微球的粒径均匀;热重分析结果表明500°C是热解Ni(HCO3)2制备NiO的适宜温度;CO2-TPD和NH3-TPD结果表明Ni(HCO3)2具有明显的酸碱双功能活性中心;透射电镜(TEM)结果表明Ni(HCO3)2颗粒是由六边形纳米片聚集而成的,且颗粒具有孔隙结构。将Ni(HCO3)2催化剂应用于苯甲醛与乙醇一步法合成安息香乙醚反应中,Ni(HCO3)2显示出优异的催化活性,反应平衡转化率高达57.5%,安息香乙醚的选择性近100%。 相似文献
10.
本发明涉及一种金属表面特种合金上的铜镍磷三元合金催化液及其制备方法,现有技术中的金属表面处理使用的化学方法,成本高,工艺复杂、污染环境。本发明主要特征是由硫酸镍、硫酸铜,次亚磷酸钠、柠檬酸钠、醋酸铵制成催化液。该催化液用于特种合金上,兵优点是工艺简单、操作方便、不污染环境、镀层致密、具有高硬度、高耐磨性及抗腐蚀性。 相似文献
11.
Catalytic synthesis of butyric esters with TiSiW12O40/TiO2 总被引:20,自引:0,他引:20
The catalytic activities of TiSiW12O40/TiO2 in synthesizing ethyl ester, propyl ester, n-butyl ester, and amyl esterwere reported. It was demonstrated that TiSiW12O40/TiO2is an excellent catalyst. Various factors concemed with esterifica-tion were investigated. The optimum conditions were found: the mole ratio of alcohol to acid is 1.3:1, the mass ratio ofcatalyst to reactants is 1.5%, and the reaction time is 1.0 h. Under the optimum conditions, the yields are 88.0% for ethylester, 94.5% for propyl ester, 98.6% for n-butyl ester, 99.1% for n-amyl ester, and 96.7% for iso-amyl ester, respectively. 相似文献
12.
Catalytic synthesis of cyclohexanone 1,2-propanediol ketal with H_4SiW_(12)O_(40)/PAn 总被引:4,自引:0,他引:4
YANG Shuijin YU Xieqing SUN Jutang Department of Chemistry Environmental Engineering Hubei Normal University Huangshi ChinaCollege of Chemistry Molecular Sciences Wuhan University Wuhan China 《稀有金属(英文版)》2004,23(4)
A new environmental friendly catalyst, H4SiW12O40/PAn was prepared and identified by means of FT-IR, XRD and TG/DTA. Cyclohexanone 1,2-propanediol ketal was synthesized from cyclohexanone and 1,2-propanediol in the presence of H4SiW12O40/PAn. The factors influencing the synthesis were discussed and the best conditions were found out. The optimum conditions are: molar ratio of cyclohexanone to 1,2-propanediol is 1:1.4, the quantity of catalyst is equal to 1.0% of feed stocks, and the reaction time is 40 min. H4SiW12O40/PAn is an excellent catalyst for synthesizing cyclohexanone 1,2-propanediol ketal and its yield can reach over 96.5%. 相似文献
13.
以TiO2和Li2CO3为原料,采用固相法合成偏钛酸型锂吸附剂前躯体Li2TiO3,将该前躯体经过盐酸洗脱锂,得到偏钛酸型锂吸附剂H2TiO3,其中锂的抽出率达到98.86%,钛几乎不溶损.对TiO2、Li2TiO3、H2TiO3以及H2TiO3吸附锂后的样品进行XRD和SEM表征.研究偏钛酸型锂吸附剂H2TiO3对锂离子的吸附性能,并用伪一级动力学方程和伪二级动力学方程对吸附过程进行拟合,计算相应的速率常数.结果表明:H2TiO3对锂离子具有较大的吸附能力,在LiOH溶液中对锂离子的吸附容量为39.8 mg/g;吸附过程符合伪二级动力学方程,表明吸附过程主要为化学吸附,吸附平衡数据符合Langmuir 等温吸附方程. 相似文献
14.
采用溶胶-凝胶法制备氧化铝颗粒增强的钼基复合材料.测定了钼基体的显微硬度;用SEM,TEM及XRD分别对混合粉体与坯体进行了微观分析;用销盘式摩擦磨损试验机测定了复合材料的滑动磨损性能.结果表明:在复合粉体及其材料中,Al2O3作为分散相具有细化晶粒的作用,随氧化铝体积分数增加,钼基体显微硬度增加,复合材料摩擦系数缓慢降低,磨损量先增加后减少,一定程度上改善了材料的磨损性能. 相似文献
15.
In order to improve the performance of molybdenum, the Mo/Al2O3 composites were prepared by using a hydrothermal method for the synthesis of the precursor powders and subsequent powder metallurgical processing. The morphologies of the composite powders and the microstructures and properties of the composites were investigated. Compared with the pure Mo powder, the grains of composite powders are smaller because of the existence of the fine Al2O3 particles. The results from the sintered composites show that the fine Al2O3 particles are evenly distributed in the Mo matrix and well bonded with the Mo matrix. With increasing Al2O3 content, all the values of the micro-hardness, compressive strength and flow stress at 0.08 strain are increased. The strengthening effect is more remarkable at elevated temperatures. At room temperature, the compressive strength and the flow stress at 0.08 strain of the composite with 40 vol.% Al2O3 are 1.67 and 2.01 times greater than those of pure molybdenum, respectively, while the values are up to 2.02 and 2.52 at 1100 °C. 相似文献
16.
以改进的Hummers法制备的氧化石墨烯为原料,采用共沉淀法获得磁性的石墨烯-Fe_3O_4载体,进而采用水热法制备出TiO_2/石墨烯-Fe_3O_4磁性三元复合光催化剂。借助X射线衍射(XRD)、扫描电子显微镜(SEM)及固体紫外-可见漫反射光谱(UV-vis DRS)对产物进行表征,并通过在紫外光和可见光下对亚甲基蓝的降解来评价复合光催化剂的催化性能及稳定性能。结果表明,Ti O_2/石墨烯-Fe_3O_4磁性三元复合光催化剂对亚甲基蓝的光催化降解符合拟一级动力学模型。该复合催化剂在紫外光和可见光下均具有较好的光催化性能,且催化活性均高于纯Ti O_2。石墨烯由于担当了载体和电子受体,增强了Ti O_2在可见光区域的吸收,能有效提高对目标污染物的光催化降解活性,同时通过添加磁性Fe_3O_4,进一步提高了其回收再利用性。 相似文献
17.
Yb2O3/TiO2纳米颗粒的制备及表征 总被引:13,自引:0,他引:13
采用溶胶-凝胶法制备了微量 Yb2O3掺杂纳米 TiO2颗粒,采用 XRD, TG-DTA, TEM等手段对试样经不同温度热处理后的结构相变、表面形貌、颗粒大小等特性进行了表征.实验表明温度不高于 400℃时,试样的颗粒粒径较小,粒径在 15 nm以下,比表面积大于 107.22 m2@ g-1, TiO2呈锐钛型;在 400℃以上, TiO2粒径迅速增大,微粒出现锐钛相与金红石相混晶结构;800℃时 TiO2微粒完全转化成金红石相. 相似文献
18.
The synthesis and crystal structure of an polyoxometalate-based organic-inorganic complex [Cu(DMF)3(H2O)2]2[SiMo12O40]·2H2O (DMF = N, N-dimethyl formamide) is described in this article. It was characterized using elemental analysis, thermal analysis, infrared, ultraviolet, and electron spin resonance spectroscopic studies. The X-ray crystallography analysis showed that the copper centers are pentacoordinated to show the square pyramidal geometry, and the polyanion [SiMo12O40]4- which is semi-coordinated to the copper(Ⅱ) centers prevents the existence of a sixth ligand. In addition, the intracationic hydrogen interaction enhanced the stability of the copper coordination cation. 相似文献
19.
WANG Jingping DU Xiaodi DUAN Xianying NIU Jingyang 《稀有金属(英文版)》2007,26(4):377-384
The synthesis and crystal smacture of an polyoxometalate-based organic-inorganic complex [Cu(DMF)3(H2O)212[SiMo12O40].2H2O (DMF = N, N-dimethyl formamide) is described in this article. It was characterized using elemental analysis, thermal analysis, infrared, ultraviolet, and electron spin resonance spectroscopic studies. The X-ray crystallography analysis showed that the copper centers are pentacoordinated to show the square pyramidal geometry, and the polyanion [SiMo12O40]4- which is semi-coordinated to the copper(I/) centers prevents the existence of a sixth ligand. In addition, the intracationic hydrogen interaction enhanced the stability of the copper coordination cation. 相似文献