合成MIBK的多元金属催化剂的制备及评价

采用浸渍法制备了适用于丙酮一步法合成甲基异丁基酮的双功能多金属催化剂。采用间歇高压反应釜在温度为160℃,压力为1.8MPa时,进行了液相丙酮1步法实验评价催化剂。考察了催化剂的载体、催化剂焙烧条件、不同金属活性组成及其含量对催化剂性能的影响。结果表明,以HZSM-5分子筛作为载体,负载Pd、Cu、Zn、Ni以载体质量为基准的质量分数分别为0.2%、0.5%、0.1%、0.8%时所制得的多金属催化剂,其丙酮的转化率为42.7%,MIBK的选择性为95.6%。多金属催化剂与单金属催化剂相比,丙酮的转化率与产品的选择性都大大提高。     

Pd/HZSM-5催化剂催化加氢丙酮合成甲基异丁基酮

以HZSM-5为载体,采用浸渍法制备系列Pd/HZSM-5催化剂,在高压连续流动固定床反应器中考察Pd/HZSM-5催化剂催化加氢丙酮一步法合成甲基异丁基酮性能,并对工艺条件进行优化。结果表明,当HZSM-5载体上Pd负载质量分数为0.5%时,在反应温度140 ℃、氢压1 MPa、空速0.48 h^-1和氢酮物质的量比为1条件下,Pd/HZSM-5催化剂催化活性较高,丙酮转化率为45.91%,甲基异丁基酮选择性为94.33%。采用XRD、H₂-TPD、SEM、EDS和TGA等对催化剂进行表征,结果表明,负载质量分数0.5%的Pd在HZSM-5分子筛表面分散均匀,且0.5%Pd/HZSM-5催化剂具有较高氢吸附能力,失活的主要原因为催化剂表面积炭,采用流化床反应器取代传统的固定床反应器可以很好的解决催化剂积炭问题。     

甲基异丁基醇气相催化脱氢制备甲基异丁基酮的工艺研究

在固定床反应器上研究了自制 CuO/ZnO/Al_2O_3为催化剂,常压下由甲基异丁基醇脱氢制备甲基异丁基酮的反应,得到了较佳的工艺条件:温度240～250℃,甲基异丁基甲醇质量空速1.0～1.5 h~(-1),催化剂还原温度低于240℃。在该条件下,甲基异丁基甲醇的单程转化率最高可达82.2%,甲基异丁基酮选择性达到99.0%。实验结果表明,在实验条件下该催化剂具有较好的稳定性。     

合成甲基异丁基酮工艺的技术经济分析

对合成甲基异丁基酮的两种工艺方法及原料路线的技术经济作了详细比较。以异丙醇为原料,常压下不用氢,在非贵金属催化剂上合成甲基异丁基酮(MIBK),较为经济合理。     

含Pd类水滑石催化剂的活性研究

用共沉淀法制备Pd类水滑石催化剂,用固定床管式反应装置测试催化剂对丙酮一步法制备MIBK的催化活性,研究了反应温度、氢酮比、进料液空速及催化剂组成对该反应的影响.在常压下,反应温度为180℃,氢酮摩尔比为1.5,液空速为1.20 h-1,选取不同组成的催化剂进行催化性能测试.结果表明:当Mg/Al比为3:1,Pd质量分数是0.2%时,丙酮的转化率达到82.87%,MIBK的选择性为53.56%,收率为44.39%.     

采用HTLcs前驱体制备的丙酮一步法制MIBK催化剂

采用共沉淀法制备Cu Mg A1三元类水滑石,进而煅烧得到CuO MgO Al2O3催化剂用于丙酮加氢一步合成甲基异丁基酮(MIBK)反应。研究了催化剂活性组分配比及反应条件对转化率和选择性的影响,经筛选得到催化剂体系的最佳组成为:n(Cu)∶n(Mg)∶n(Al)=4∶16∶10,适宜的反应条件为:温度240℃,n(H2)∶n(丙酮)=2.5,液空速为4.8mL/h·g,在该条件下丙酮转化率达73.88%,MIBK选择性达55.23%。     

锆硅氧化物的合成及其在合成甲基异丁基酮中的应用

采用溶胶-凝胶法制备了不同锆硅比的混合氧化物,制备过程中引入钯制得多功能催化剂,并将催化剂用于丙酮一步法合成甲基异丁基酮的反应。结果表明,随着催化剂中硅含量增加,丙酮转化率降低,甲基异丁基酮选择性升高;锆含量高的催化剂表现出较好的丙酮转化率,但甲基异丁基酮选择性较低。     

MIBC脱氢制备MIBK宏观动力学研究

采用共沉淀法制备的铜系CuO/ZnO/Al2O3脱氢催化剂,在常压下进行了甲基异丁基甲醇的气相脱氢制备甲基异丁基酮的反应实验.研究了单管反应器中反应温度和MIBC进料液时空速对脱氢反应的影响,并建立了宏观动力学方程.结果表明在温度为483～513 K,液时空速为1.0～2.0 h-1的条件下,甲基异丁基甲醇脱氢单程转化率最高达到91.11%,甲基异丁基酮的选择性大于99.0%.将实验结果用最小二乘法拟合得到该反应的宏观动力学方程为,其中k = 9.542×107exp(-E / RT),E为58.08 kJ·mol-1.动力学方程的关联线性度和方差分析计算表明,所建立的宏观动力学方程较好地描述了甲基异丁基甲醇的气相脱氢反应.     

丙酮一步法合成甲基异丁基酮(MIBK)的工艺研究

简介了甲基异丁基酮(MIBK)的生产方法。对以丙酮和氢为原料合成MIBK的工艺进行了研究,考察了反应相态、进料方式、温度、压力、空速、氢/酮比等因素对反应的影响,同时确定了最佳反应条件。在此条件下,丙酮的转化率为30%~35%,MIBK的选择性可达94%~95%。此工艺的中试和工业化结果均重复了小试结果。     

荷兰开发合成甲基异丁基酮用多相催化剂

荷兰Utrecht大学开发了用于合成溶剂甲基异丁基酮（MIBK）的多相催化剂。该催化剂以浸渍在碳纳米纤维上的活性水滑石为基础，其中活性水滑石是由镁和氢氧化铝组成的层状粘土。该MIBK生产工艺以丙酮与氢气为原料，通过过滤即可从产物中回收催化剂。传统的MIBK生产工艺采用均相催化剂，会产生大量废水，且需要附加提纯步骤将催化剂从产物中去除。     

合成甲基异丙基酮和二乙基酮的Na-Pd/ZrO2-MnOx-ZnO催化剂的制备与表征

考察了催化剂组成、还原温度和反应条件对Na Pd/ZrO2 MnOx ZnO催化剂性能的影响,并用BET、XRD和NH3 TPD、CO2 TPD等技术对催化剂进行了表征。研究表明,用此方法制备的ZrO2 无晶相衍射峰,是无定型的。当n(Zr)∶n(Mn)∶n(Zn) =2 0∶(0 2~0 5)∶1 0时,既无明显的ZnO晶相衍射峰,也无明显的MnOx晶相衍射峰,ZrO2、MnOx、ZnO生成固溶体,并引起平均孔径增大和比表面积减小。ZrO2、MnOx、ZnO生成固溶体的孔径较大的催化剂具有更高的活性。x(Pd) =0 25%、x(Na) =0 29%、n(Zr)∶n(Mn)∶n(Zn) =2 0∶(0 2~0 5)∶1 0的催化剂,在常压、温度643K、原料液相空速1 0h-1条件下,甲基乙基酮的转化率达39 6%,甲基异丙基酮和二乙基酮的选择性分别为45 5%、32 2%。     

仲丁醇脱氢催化剂性能

采用XRD、TPR、BET和N2O滴定法对仲丁醇脱氢催化剂YTDH-1G与对比剂A进行表征,并采用常压固定床反应器考察两种催化剂的仲丁醇脱氢活性和甲乙酮选择性。结果表明,催化剂中添加Zr O2后可以提高催化剂活性组分的分散度,改善催化剂的还原性能。催化剂YTDH-1G表明的Cu比表面积和分散度明显大于对比剂A。在考察的实验范围,催化剂YTDH-1G的催化活性和产物选择性优于对比剂A,对工艺条件的适应性较强,可在较宽的温度和空速范围使用,具有较好的工业应用前景。     

Ni-Na/Zr02-Mn02-Zn0催化合成甲基异丙基酮和二乙基酮（英文）

ZrO2-MnO2-ZnO supports were prepared by the co-precipitation method,and then Ni-Na/ZrO2-MnO2-ZnO catalysts were prepared by the impregnation method.In this paper,the reactions to synthesize methyl isopropyl ketone and diethyl ketone by the one-step synthesis method over this catalyst were studied,and meanwhile,the impact of the catalyst preparation conditions and the reaction conditions on catalyst performance was also investigated.It was observed that under the conditions when Ni loading was 25%,calcination temperature was 400℃ and reduction temperature was 410℃,this catalyst had good catalytic performance on the reaction.The suitable reaction conditions were achieved:reaction temperature was 400℃;reaction at atmospheric pressure;liquid hourly space velocity of raw material of 0.5 h 1 ;and the molar ratio of(methanol)/(methyl ethyl ketone)/(water) was equal to 1/1/1.Under such conditions,the conversion of methyl ethyl ketone could achieve 41.7%,and the overall selectivity of methyl isopropyl ketone and diethyl ketone could achieve 83.3%,which was comparable to the conversion of 38.1% and the selectivity of 82.2% achieved by using palladium as the active material.The good stability made this catalyst have good prospects for industrial application.     

Selective hydrogenation of acetylene on Nanosized catalysts

The use of unconventional methods for the preparation of Nanosized catalysts for the selective hydrogenation of acetylene and its homologs is considered. Based on published data and experimental data obtained in this work, it is shown that catalysts based on nanoparticles of palladium have a high activity, although their selectivity and stability are low. Bimetallic palladium-containing systems are more promising. The most interesting of them are nanocomposites containing palladium and silver or palladium and zinc particles. Another method that makes it possible to increase the selectivity and stability of the catalysts for the hydrogenation of triple bonds is the use of synergism in gold-nickel nanocomposites. The preparation of nanosized hydrogenation catalysts by a recently developed method of laser electrodispersion is considered. This method makes it possible to prepare catalysts with a very narrow distribution of nanoclusters over sizes and with very high specific activity and stability.     

钯基乙炔选择性加氢催化剂研究进展

催化选择加氢去除乙烯中微量乙炔是石化工业重要的反应过程,工业钯基催化剂选择性低、催化剂使用寿命较短。本文综述了近年来国内外乙炔选择性加氢钯基催化剂的研究进展。主要探讨了过渡金属、金属氧化物与非金属配体助剂能调变钯粒子空间结构,隔离分散钯粒子并与钯粒子产生电子效应;阐明了钯粒子尺寸与织构形貌的调控能改变钯的晶面结构,影响钯对乙烯的吸脱附和对氢气的活化与解离性能;评述了单一氧化物、复合金属氧化物、碳材料等载体为催化剂提供合适的表面酸碱性并加强了与活性中心之间的相互作用,稳定钯粒子抑制其发生迁移与团聚。提高乙烯选择性与催化剂稳定性是该研究的重点与难点,负载型钯基催化剂的发展方向是构建高分散钯粒子,并在反应过程中保持稳定。     

The influence of the structural and electronic characteristics of palladium on the activity and selectivity of Pd/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> and Pd-Co/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts for the hydrogenation of acetylene hydrocarbons

The influence of the structural and electronic characteristics of nonpromoted and cobalt-promoted Pd catalysts on their adsorption and catalytic properties is studied. It is shown that the conversion of vinylacetylene depends on the dispersion of palladium for both types of catalysts synthesized from acetate and acetylacetonate complexes. The palladium acetylacetonate catalysts have a higher palladium dispersion than the samples obtained from acetate complex solutions, thus leading to a higher conversion of vinylacetylene. It is established that the selectivity of vinylacetylene conversion into 1,3-butadiene on palladium acetate and acetylacetonate catalysts depends on the state of the 3d orbitals of surface Pd atoms. The palladium acetate catalysts are characterized by a higher electron density on the 3d orbital in comparison with the acetylacetonate samples, thus producing higher selectivities of vinylacetylene conversion into 1,3-butadiene. The introduction of cobalt into Pd/δ-Al₂O₃ catalyst synthesized from acetylacetonate complex leads to the formation of bimetallic Pd-Co particles, in which Pd atoms have higher electron density than those in the nonpromoted Pd/δ-Al₂O₃ catalyst, due probably to the donation of electron density from promoter atoms, with a resulting decline in the adsorption ability of bimetallic particles with regard to 1,3-butadiene and hydrogen. As a consequence, the selectivity of vinylacetylene conversion into 1,3-butadiene increases. Requirements for the size, dispersion, and electronic characteristics of the active component in the catalysts for the selective hydrogenation of vinylacetylene are formulated, and two techniques for their synthesis are proposed.     

纳米Zn/HZSM-5分子筛催化丙烷芳构化

采用低温老化、高温晶化两步法在Na2O-Al2O3-SiO2-四丙基氢氧化铵(TPAOH)-H2O体系中水热合成了纳米ZSM-5分子筛。用BET、N2吸/脱附曲线和NH3-TPD等手段对负载Zn的纳米HZSM-5分子筛结构和酸性进行了表征。结果表明,与微米Zn/HZSM-5分子筛催化剂相比,所制备的纳米Zn/HZSM-5催化剂比表面积明显增大,总酸量和弱酸量增加;在丙烷芳构化反应中,纳米Zn/HZSM-5分子筛具有更佳的催化活性、稳定性和芳烃选择性。     

The influence of acidity of carbon nanofibre-supported palladium catalysts in the hydrogenolysis of hydroxymatairesinol

The lignan hydroxymatairesinol (HMR, extracted from Norway spruce knots) was hydrogenolysed to matairesinol (MAT) over palladium supported by carbon nanofibres (Pd/CNF) in 2-propanol at 70 °C under hydrogen flow. The influence of support acidity on the activity and the selectivity to MAT was studied. The acidity of the Pd/CNF catalyst was varied by heat-treatment at different temperatures in nitrogen flow. The catalysts were characterized by transmission electron microscopy (TEM), inductively coupled plasma emission mass-spectrometry (ICP-MS, metal content), H₂-chemisorption (dispersion, metal particle size), and titration using NaOH. A more acidic support material was more active and selective to the desired product MAT. The major byproduct was 7-iso-propoxymatairesinol resulting from a reaction of the solvent with HMR over the acid sites on the support. The hydrogenolysis of HMR to MAT requires both the presence of metal and acidity.     

超声辐射下钯系加氢催化剂的新型制备方法

提供了一种钯系加氢催化剂新型制备方法。采用经β-环糊精改性载体,以醋酸钯为活性组分前驱体在超声辐射下进行催化剂有机相制备;并以碳三液相加氢为探针反应,对利用4种不同方法制备的催化剂进行200 h对比评价。结果表明,该方法可有效提高活性组分分散度,使催化剂在保持较好加氢活性的同时具有较好的加氢选择性,为优化钯系加氢催化剂综合性能提供一条行之有效的途径。