共查询到17条相似文献,搜索用时 109 毫秒
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以Al_2O_3为载体,RuCl_3·xH_2O和FeCl_3·6H_2O为活性组分前驱体,采用吸附-沉淀法制备了Ru-Fe/Al_2O_3和Ru/Al_2O_3催化剂,以马来酸二甲酯加氢合成丁二酸二甲酯为探针反应,结合H_2-TPR和XRD表征技术,考察Fe改性Ru基催化剂的氧化-还原性能及催化活性。经氧化-还原循环处理后,催化剂Ru-Fe/Al_2O_3上马来酸二甲酯加氢活性高于Ru/Al_2O_3。XRD结果显示,经处理的Ru-Fe/Al_2O_3上未见金属Ru的特征衍射峰,而Ru/Al_2O_3上出现了金属Ru的特征衍射峰。结合H_2-TPR结果推断,Ru与Fe之间发生了相互作用,这种协同作用可以改善Ru/Al_2O_3催化剂的热稳定性。 相似文献
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通过超声辅助NaBH4还原法制备了3%Ru/CN催化剂(Ru的质量分数),该催化剂用于对苯二甲酸二甲酯(DMT)加氢制备1,4-环己烷二甲酸二甲酯(DMCD)。采用Raman、SEM、TEM、N2吸脱附、XRD、XPS等对载体和催化剂的组成、表面性质进行表征,结果表明,氮元素成功掺入碳骨架中且氮掺杂碳材料为介孔结构。研究了催化剂的用量、反应温度、H2 压力、反应时间等对催化剂加氢性能的影响。结果表明,当反应物用量为1.00 g,催化剂(含载体)用量为0.05 g,反应温度140 ℃,反应压力5.0 MPa,反应时间1 h时,DMT转化率为100%,DMCD选择性为99.3%。3%Ru/CN-1000催化剂循环使用5次后,催化剂催化性能未见明显下降,DMT转化率为98.8%,DMCD选择性为99.7%。 相似文献
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《应用化工》2017,(9):1773-1778
采用并流共沉淀法制备了醋酸甲酯催化加氢合成乙醇的CuO-ZnO/Al_2O_3催化剂,并通过N_2物理吸附、X射线衍射(XRD)、程序升温还原(H_2-TPR)、扫描电子显微镜(SEM)等表征手段分析了催化剂的物理化学特性,探究加料方式、铜锌铝的配比对催化剂结构的影响与催化剂活性之间的关系。结果表明,加料方式为并流、铜锌铝的配比为5∶2∶1时,催化剂前驱体的架构最为规整,焙烧后得到的CuO颗粒较小,且分散最为均匀,具有较多且分散的活性组分,表现出了最优的加氢性能。在反应温度220℃,反应压力3.0MPa,质量液时空速0.5h-1和氢酯物质的量比9的条件下,醋酸甲酯的转化率达到97.6%,乙醇的选择性高达97.5%。 相似文献
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《应用化工》2022,(9):1773-1778
采用并流共沉淀法制备了醋酸甲酯催化加氢合成乙醇的CuO-ZnO/Al_2O_3催化剂,并通过N_2物理吸附、X射线衍射(XRD)、程序升温还原(H_2-TPR)、扫描电子显微镜(SEM)等表征手段分析了催化剂的物理化学特性,探究加料方式、铜锌铝的配比对催化剂结构的影响与催化剂活性之间的关系。结果表明,加料方式为并流、铜锌铝的配比为5∶2∶1时,催化剂前驱体的架构最为规整,焙烧后得到的CuO颗粒较小,且分散最为均匀,具有较多且分散的活性组分,表现出了最优的加氢性能。在反应温度220℃,反应压力3.0MPa,质量液时空速0.5h-1和氢酯物质的量比9的条件下,醋酸甲酯的转化率达到97.6%,乙醇的选择性高达97.5%。 相似文献
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Fe_2O_3/Al_2O_3催化剂制备及催化降解酸性染料废水 总被引:1,自引:0,他引:1
以γ-Al2O3>为载体,采用浸渍-焙烧法制备了Fe2O3/Al2O3催化剂.并将其用于催化降解模拟酸性大红-3R染料废水.对于质量浓度为1 000 mg/L的高浓度酸性大红-3R染料废水,最佳的处理工艺条件为:温度60℃、pH=3.0、H2O2投加质量浓度9.4g/L、催化剂投加质量浓度1.5 g/L.在此工艺条件下酸性大红染料废水的降解率为99%,CODCr的去除率>83%.而对于质量浓度≤100 mg/L的酸性大红-3R染料废水在此条件下的降解速率接近100%.且催化剂连续使用6次后仍有较高的催化活性. 相似文献
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为了研究载体性质对Ru负载型催化剂的CO2加氢合成甲酸反应性能的影响,制备了以Al2O3纳米棒和γ-Al2O3为载体的一系列Ru基催化剂,采用透射电镜(TEM)、X射线衍射(XRD)、D2/OH交换和程序升温还原(H2-TPR)等方法详细表征催化剂的性质,并考察CO2加氢制甲酸的反应性能。结果表明:与传统Ru/Al2O3催化剂相比,以Al2O3纳米棒为载体时,Ru Ox物种在载体表面的分散程度高,Al2O3纳米棒的表面OH数目多,有利于提高催化剂的反应活性,另外当Ru在Al2O3纳米棒上的负载量(质量分数)为1%时,甲酸产量最高可以达到11.7mmol/h。 相似文献
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Ni/Al_2O_3催化剂是甲烷二氧化碳重整反应制取合成气研究最多、最具应用潜力的一种催化剂。通过对催化剂进行CO_2-TPD研究,考察还原态Ni/Al_2O_3催化剂的CO_2脱附特性。结果表明,浸渍法制备的Ni/Al_2O_3催化剂CO_2脱附曲线呈现双峰,分别在(60~65)℃和(350~380)℃出现高低温两个活性位;高温CO_2吸附量为3.0 cm~3·g~(-1),低温CO_2吸附量为24.0 cm~3·g~(-1)。催化剂的CO_2吸附量与其Ni含量无关。考察选用不同载体的CO_2脱附行为,发现以Al_2O_3为载体的催化剂CO_2吸附量是MgO和SiO_2为载体催化剂的2~4倍,以TiO_2为载体的催化剂几乎不吸附CO_2。 相似文献
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The kinetics of citral hydrogenation in ethanol over an Ni/Al2O3 catalyst was studied in a slurry reactor operating at atmospheric pressure and at a temperature range of 60–77°C. Citronellal was the primary reaction product, whereas the amounts of unsaturated alcohols were very minor. Citronellol was the dominating product, generated mainly through the hydrogenation of the carbonyl group of citronellal. Based on the experimental data, a kinetic model was developed for hydrogenation. The model comprises competitive and rapid adsorption steps as well as rate-determining hydrogenation steps. The mass transfer limitation of hydrogen was included in the mathematical model. The kinetic parameters and the mass transfer parameter of hydrogen were estimated from the experimental data. A comparison of the model predictions with the experimental data revealed that the proposed kinetic approach gave a satisfactory reproduction of the data. 相似文献
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采用浸渍法制备了稀土镧和铈改性的CuNi/Al2O3催化剂,研究了稀土负载量对催化剂活性和选择性的影响,并研究了催化剂的还原性能。结果表明:La和Ce的存在均降低了活性相CuO和NiO的还原温度,使改性催化剂具有更高的催化活性,但催化剂上乙烯的选择性则是Ce改性催化剂高于La改性催化剂,NCeO2含量为l%时,CeCuNi/Al2O3催化剂上乙炔转化率达到98%,乙烯选择性和收率则分别达到84%和82.3%,比未改性的CuNi/Al2O3催化剂上乙烯收率高16.4%,显示出CeO2改性CuNi/Al2O3催化剂的优异性能。 相似文献
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A kinetic model was developed for the enantioselective hydrogenation of 1-phenyl-1,2-propanedione based on parallel racemic and enantioselective routes in the presence of cinchonidine. The Langmuir–Hinshelwood type of competitive adsorption approach was used in the model, which was combined with a batch reactor model. The proposed model could sufficiently describe the observed kinetic results. 相似文献
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Ana Cristina Alves Monteiro-Gezork Reyna Natividad John Mike Winterbottom 《Catalysis Today》2008,130(2-4):471-485
The importance of the hydrodearomatisation (HDA) is increasing together with tightening legislation of fuel quality and exhaust emissions. The present study focuses on hydrogenation (HYD) kinetics of the model aromatic compound naphthalene, found in typical diesel fraction, in n-hexadecane over a NiMo (nickel molybdenum), Ni (nickel) and Ru (ruthenium) supported on trilobe alumina (Al2O3) catalysts. Kinetic reaction expressions based on the mechanistic Langmuir–Hinshelwood (L–H) model were derived and tested by regressing the experimental data that translated the effect of both naphthalene and hydrogen concentration at a constant temperature (523.15 and 573.15 K over the NiMo catalyst and at 373.15 K over the Ni and Ru/Al2O3 catalysts) on the initial reaction rate. The L–H equation, giving an adequate fit to the experimental data with physically meaningful parameters, suggested a competitive adsorption between hydrogen and naphthalene over the presulphided NiMo catalyst and a non-competitive adsorption between these two reactants over the prereduced Ni and Ru/Al2O3 catalysts. In addition, the adsorption constant values indicated that the prereduced Ru catalyst was a much more active catalyst towards naphthalene HYD than the prereduced Ni/Al2O3 or the presulphided NiMo/Al2O3 catalyst. 相似文献