电位法测定加氢催化剂中的硼含量

利用氟硼酸根离子选择电极对加氢催化剂中硼含量进行了测定,详细考察了实验条件及镍、钨、铝等离子的干扰。测定结果令人满意,相对标准偏差＜０．１８％。     

电位滴定用于乙醛酸的分析

利用电位滴定仪 ,以 DMF作为溶剂能方便准确地测定出乙二醛液相氧化液中乙醛酸的含量。其中乙醛酸的相对标准偏差为 0 .61 88%～ 1 .0 5 3% ;乙醛酸的回收率为 :98.0 8%～ 1 0 2 .2 0     

电位滴定法测定二羧酸钠

采用间接电位滴定法,以丙酮为溶剂,在室温下测定了混合二羧酸钠的含量。本方法操作简单、快速、准确     

Gas/Surface Titration Microcalorimetry. Energetics of Oxygen Adsorption on Supported Iridium Catalysts

Measurements of the heat of adsorption of hydrogen on Ir/Al₂O₃ catalysts of different metal particle size were made by employing adsorption microcalorimetry. The values of this quantity were different for each sample and the results also indicated the heterogeneity of the iridium surface. In contrast to this, the heat of adsorption of oxygen measured on the same samples in the same manner was practically the same for all of them. The heat of oxygen adsorption as presented in the differential calorimetric isotherms was constant up to half the monolayer coverage for all the samples. This result is unexpected and in contradiction to the presence of surface heterogeneity in the iridium crystallites, as revealed by hydrogen adsorption. To clarify these anomalies the energetics of oxygen adsorption was determined using a different method. Titration experiments with hydrogen of preadsorbed oxygen were carried out. The heat of adsorption of oxygen was calculated from these results by means of adopting a thermochemical cycle. The values of heat of adsorption obtained as a function of the amount adsorbed unveiled the heterogeneity of the iridium surface. The differences found between the samples can be correlated to both the different particle size and degree of sintering of the samples.     

电导滴定法测定浆料中对苯二甲酸含量

用氨水做溶剂,使对苯二甲酸溶解,并形成对苯二甲酸铵,用ＮａＯＨ标准溶液滴定ＮＨ＾＋４,通过计算 得对苯二甲酸的含量,本方法简便,准确,重现性和于浆料中对苯二甲酸含量的测定,结果令人满意。     

连续滴定法测定硅氟酸电解液中硅氟酸和铅

在电解液中加入饱和硫酸钾,使硅氟酸和铅生成沉淀与其他元素分离,用氢氧化钠滴定硅氟酸后,再用EDTA滴定溶液中的铅。硅氟酸回收率为97.9%~101.3%,铅回收率为97%~102.07%,方法简单,准确,快速,可满足生产的要求。     

蒙脱土负载型固体酸催化剂的烷基化性能与结构研究

以酸化后蒙脱土为载体，采用浸渍蒸发法制备了环境友好的蒙脱土负载znCl2型固体酸催化剂。研究了蒙脱土酸化处理、ZnCl2负载量及活化温度对催化剂烷基化活性的影响，并初步考察了催化剂的稳定性，比较了几种不同酸催化剂的烷基化活性。利用XRD、BET、TG—DTA、吡啶吸附FTIR对催化剂的结构进行了表征和测定；结果表明，蒙脱土酸化处理后形成的孔道有利于负载ZnCl2，ZnCl2与蒙脱土的羟基之间存在着化学键合，经活化后转化成Zn(0H)C1。蒙脱土负载ZnCl2后明显地提高蒙脱土表面的总酸量，催化剂活性与其表面总酸量之间有关，催化剂表面L酸与B酸的共存有利于其烷基化活性的提高。实验条件下，蒙脱土负载ZnCl2型催化剂在苯与氯节的烷基化反应中表现出较高的催化活性，二苯甲烷的收率最高可达83．6％。与其它Lewis酸试剂及酸化蒙脱土相比，蒙脱土负载型催化剂催化活性大有提高。     

高氯酸电位滴定法测定对氨基苯甲酸正丁酯的含量

研究了用高氯酸标准溶液对对氨基苯甲酸正丁酯含量的非水滴定,具体方法为:精确称量对氨基苯甲酸正丁酯,用约25 mL的冰醋酸微热溶解。用配制好的高氯酸进行电位滴定,应用一阶导数法得出滴定结果。此方法容易操作,回收率在98.5%~103.9%之间。     

电导滴定法测定聚酯浆料中对苯二甲酸含量

对苯二甲酸溶解于氨水,并形成Ｈ４ＮＯＯＣ－（）－ＣＯＯＮＨ４．用ＮａＯＨ标准溶液进行电导滴定,求得对苯二甲酸的含量。本方法简便、准确、重现性好。用于聚酯浆料中对苯二甲含量的测定,结果令人满意。     

酸性镀铜液中氯离子的自动电位滴定

采用自动电位滴定法测定酸性镀铜液中的氯离子,研究了镀液中各种成分对测定的影响。实验结果表明,本法简便、快捷。分析结果准确可靠。     

双点电位滴定法测定油脂的酸价

改进了林文如酸碱双点电位滴定方法,导出了不作近似的计算公式,并对该方法准确度进行了探讨。用于鱼酸价测定,其相对误差皆小于１％。．     

O，O—二异丙基二硫代磷酸的制备及分析方法

分析了影响二烷基二硫化代磷酸的合成和提纯的主要因素,通过控制原料异丙醇的滴加温度和提纯时的碱化pH值,以P2S5和异丙醇反应制备了纯度较高的二异丙基二硫化磷酸（HDDP）,探讨了溴量法分析HDDP纯度的可行性和精度。     

光亮镍镀液中硼酸含量的自动电位滴定

研究了光亮镍镀液中硼酸含量自动电位滴定的条件和方法。实验结果表明,用柠檬酸钾作掩蔽剂,防止Ni~(2+)的沉淀和其它重金属离子的干扰;加入丙三醇溶液,以pH复合电极为指示电极,进行自动电位滴定来测定硼酸,方法简便快捷,分析结果准确可靠。     

钌基氨合成催化剂载体研究进展

钌基氨合成催化剂作为一种负载型催化剂,载体对催化剂活性有直接影响。本文对国内外广泛研究的活性炭载体．氧化物载体以及一些新型的载体作了评述,并对未来的研究方向进行了展望。     

大孔PVC树脂负载H3SiW12O40催化剂的酸性研究

以大孔PVC树脂为载体．负载Keggin型杂多酸H3SiW12O40经过处理后得到了一种新型的杂多酸催化剂。本文采用电化学分析法测定负载杂多酸催化剂的总酸量及强、中、弱三种不同强度酸位的酸量,用吡啶-红外光谱测定出Bronsted酸和Lewis酸的比例．从而得出催化剂中Bronsted酸和Lewis酸的酸量及不同酸位的酸类型。     

负载型固体酸催化制备生物柴油研究进展

负载型固体酸催化剂具有无腐蚀、分离容易、对环境不产生污染、原料适应性广等优点,已成为制备生物柴油首选的绿色催化剂。本文综述了负载型固体酸催化剂制备原理、生产工艺、研究方法及其结构表征,分析了负载型固体酸自身结构与油脂酯交换反应催化活性的关系,预测了负载型催化剂在生物柴油制造业的应用前景。     

氧化镍的快速螯合滴定

本文采用加入掩蔽剂掩蔽干扰离子，用ＥＤＴＡ直接螯合滴定镍。方法简便、快速、实用，具有良好的精密度和准确度。     

脂肪酸（或酯）加氢制脂肪醇催化剂进展及评述

论述了脂肪酸（或酯）加氢传统的工业催化剂，以及近年来开发进展的温和条件下的中压催化性能及评述。     

Characterization and Catalytic Oxidation of Carbon Monoxide Over Supported Cobalt Catalysts

Three types of supported cobalt catalysts (CoO_x/SiO₂, CoO_x/TiO₂ and CoO_x/Al₂O₃) were prepared by incipient wetness impregnation with aqueous Co(NO₃)₂·6H₂O solution. The phase composition and the interactions of cobalt with supports under different calcined temperatures were investigated using thermogravimetry (TG), N₂-adsorption at −196 °C, X-ray diffraction (XRD), temperature-programmed reduction (TPR) and diffuse reflectance spectroscopy (DRS). Their catalytic activities towards the CO oxidation were further studied in a continuous flow micro-reactor. The results showed that the interaction of cobalt oxide with supports was much stronger in the kinds of Al₂O₃ and TiO₂, while no conclusive evidence of any interaction was found for SiO₂. Besides the crystalline Co₃O₄ which was formed in three supported catalysts, both high-temperature phases CoAl₂O₄ and CoTiO₃ spinel were also detected under XRD, DRS and TPR analysis. The degree of interaction between cobalt oxide and the support not only affected the surface area and reduction behavior of the catalysts, the catalytic activity toward the CO oxidation also affected simultaneously. As the CoAl₂O₄ and CoTiO₃ spinel formed, both the surface area and catalytic activity decreased significantly.     

Synthesis of Pseudoionones by Acid and Base Solid Catalysts

The preparation of pseudoionones by aldol condensation reaction between citral and acetone have been carried out in the presence of acid (HY and beta zeolites), an acid–base (amorphous aluminophosphate) and basic catalysts such as an aluminophosphate oxynitride, MgO and different activated hydrotalcites. The results showed that acid or acid–base catalysts were not successful for performing in one pot the preparation of ionones. MgO and calcined hydrotalcites showed excellent activity and selectivity to pseudoionones, with calcined hydrotalcite more selective than MgO. Moreover, the rate of reaction can be improved by activating the hydrotalcite through rehydration. This activation can be successfully done by simply adding the optimum amount of water to the calcined hydrotalcite before reaction. The inhibiting effect of the concentration citral on the catalytic activity of rehydrated hydrotalcites that has been reported to occur at 273 K can be avoided by working at a reaction temperature of 333 K.