厄他培南合成用钯炭催化剂制备及性能评价

以乙醇改性活性炭为载体,采用沉积-沉淀法制备10%Pd/C催化剂,考察不同还原剂对厄他培南收率及废Pd/C催化剂Pd回收率的影响。结果表明,采用硼氢化钠和水合肼还原催化剂,废Pd/C催化剂的Pd回收率大于90%,明显高于甲酸和甲醛还原的催化剂,但水合肼还原催化剂的厄他培南收率较低。     

钯碳催化剂的制备条件对苯酚气相加氢制环己酮的影响

采用浸渍法制备了Pd/C催化剂,考察了活性炭预处理方法、沉淀温度和还原方法对催化剂催化苯酚气相加氢制环己酮的影响。通过XRD和XPS对催化剂进行表征,考察了催化剂制备条件对Pd/C催化剂结构和催化活性的影响。结果表明:双氧水预处理可以向载体表面引入氧化性基团,促进钯在载体中的分散;在活性炭酸洗过程中进行搅拌,可以减少落粉的产生,提高催化剂的活性;沉淀温度升高会导致催化剂中Pd晶粒度变大;Pd晶粒度过小或过大都会导致催化剂活性下降;采用水合肼还原有利于提高催化剂的活性。     

活性炭改性对松香歧化用Pd/C催化剂性能的影响

采用沉积-沉淀法制备了4% Pd/C催化剂（Pd质量分数4%）,分别以硝酸、盐酸、双氧水和氨水4种溶剂对Pd/C的载体活性炭进行改性,并对载体活性炭的比表面积和孔结构、零电荷点（PZC）以及活性组分Pd的分散度进行了表征,研究了活性炭改性对Pd催化剂在松香歧化反应中催化性能的影响。结果表明：经氨水改性后活性炭比表面积孔径增大且活性炭PZC值升高,有利于活性组分Pd在载体表面的分散,以氨水改性活性炭为载体制备得到的Pd/C催化剂活性最高,在催化剂投料量为0.03%,280℃反应2 h条件下,脱氢枞酸质量分数高达81.7%。     

2,6-二甲基苯酚原位还原胺化反应研究

采用浸渍法制备Pd基催化剂,用于甲醇水相重整反应与2,6-二甲基苯酚还原胺化反应的耦合。研究载体、甲醇用量、反应温度、催化剂用量以及反应时间等因素的影响,结果表明,在Pd基催化剂作用下,可以实现甲醇水相重整反应与2,6-二甲基苯酚还原胺化反应的耦合,2,6-二甲基苯酚还原胺化反应按照加氢-胺化-加氢-脱氢机理进行,Pd/C催化剂同时具备制氢、加氢、胺化和脱氢的均衡性能,是理想的耦合催化剂。     

Pd/C催化剂上烯酮的选择性加氢反应

采用釜式反应器,在无溶剂条件下考察了金属Pd的负载量、催化剂粒度、载体预处理方式和反应温度等因素对Pd/C催化剂6,10,14-三甲基-13-烯-2-十五烷酮(FA-4H)选择性加氢性能的影响规律。实验结果表明:随着Pd负载量的增加,Pd/C催化剂FA-4H加氢的活性逐渐增加;当Pd负载量在0.5%~3.0%(wt),FA-4H完全转化时目标产物六氢法呢基丙酮(PA)的选择性为99.3%~99.5%。较小的催化剂粒度对应较短的催化剂孔道,有利于减少产物PA在催化剂孔道内停留的时间,从而在一定程度上防止了C=O双键的过度加氢。此外,活性炭载体的硝酸或氨水预处理、较低的反应温度等也有利于减少Pd/C催化剂上FA-4H完全转化时加氢副产物6,10,14-三甲基-13-烯-2-十五烷醇(FA-alcohol)和6,10,14-三甲基-2-十五烷醇(PA-alcohol)的生成量,从而使目标产物PA的选择性接近100%。     

CFC-115加氢脱氯制HFC-125 Pd/C催化剂制备研究

以商品化活性炭为载体、贵金属Pd为活性组分,采用浸渍法制备了一系列Pd/C催化剂.在常压固定床微型反应器中,以CFC-115加氢脱氯生产臭氧消耗物质(ODS)替代品HFC-125为目标反应,评价了催化剂的性能.详细考察了载体预处理硝酸浓度、载体粒径、Pd源前驱体及溶剂等制备条件对其催化性能的影响.在研究的范围内,采用粉末活性炭为载体,Pd(NO_3)_2为Pd源,甲醇为溶剂制备的催化剂具有最好的催化性能.     

Pd/C催化剂制备条件优化及其在4-氨基二苯胺生产中的应用

采用浸渍法制备了Pd/C催化剂,考察了催化剂制备过程中加料方式、还原方法、载体种类、钯质量分数和浸渍液质量浓度对催化剂性能的影响,得到了制备Pd/C催化剂的优化工艺条件:载体为NH-03型活性炭,浸渍液质量浓度为20 g/L,采用滴加的方式将PdCl_2溶液加至活性炭浆液中,还原剂为(w)20%的次亚磷酸钠溶液,钯质量分数为5%。优化制备条件下制得的Pd/C催化剂用于催化加氢制备4-氨基二苯胺,表现出较好的活性,其中4-硝基二苯胺和4-亚硝基二苯胺转化率均可达到100%,4-氨基二苯胺选择性大于99%,加氢反应时间小于30 min。催化剂SEM表征结果表明:自制的Pd/C催化剂表面活性炭载体凸起部分与Pd粒子粒径相当,有利于Pd粒子在活性炭表面的负载,提高Pd粒子的吸附牢固度和分散性,进而提高了Pd/C催化剂的活性。     

载体的碱处理对Pd/C催化剂电催化性能的影响

将活性炭放入质量分数为10%的NaOH溶液中进行预处理,然后将其与未处理的活性炭分别作为载体制备Pd/C催化剂。对比两种催化剂的电化学性能发现,预处理的活性炭所制备的Pd/C催化剂,在甲酸电催化氧化活性和稳定性方面好于未处理的活性炭所制备的Pd/C催化剂。     

HPO法合成羟胺催化剂Pd+Pt/C的制备研究

本文对NO₃^－加氢还原制羟胺的Pd+Pt/C催化剂进行了研究,考察了载体活性炭来源、预处理条件、Pt添加量、助剂种类和用量等因素对催化剂性能的影响。研究表明选择大、中孔比例高(≥70％)的活性炭做载体,并进行适当的表面处理,可改善活性组份Pd、Pt的分散度和提高对产物羟胺的选择性。添加一定量Pt(≤20%)可显著提高催化剂活比。XRD物相分析表明还原反应活性中心可能是Pd-Pt合金。实验还确定了GeO₂为合适的助剂,其最佳添加范围为2-4mgGeO₂/g.cat     

载体对不饱和醛/酮中C=O选择性加氢催化剂性能的影响

研究载体活性炭对沉淀法制备的Pd/C催化剂催化活性的影响,在不饱和醛/酮加氢反应中通过考察载体粒度和试剂改性等条件对催化剂催化活性以及C=O选择性的影响。结果表明,将粒度(100~200)目的活性炭在80℃的10%HNO_3溶液中浸泡120 min,洗涤干燥后得到活性炭载体制备的Pd/C催化剂具有较高的活性和C=O选择性,不饱和醛转化率达95.2%,不饱和醇选择性达96.3%。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997