Hydrogenation of aromatic compounds in the presence of dibenzothiophene over bimetallic catalysts containing mesoporous aluminosilicates

The hydrogenation of a mixture of naphthalene, tetralin, and toluene (a solution in n-heptane) in the presence of dibenzothiophene (150 and 400 ppm on a sulfur basis) over Pt-Pd catalysts containing Al-HMS mesoporous aluminosilicates has been studied. The catalyst supports contained 35 wt % Al-HMS and 65 wt % γ-Al₂O₃. The Pt and Pd loadings in the catalysts were 0.2 and 0.8 wt %, respectively. The process was carried out at 200–240°C, a pressure of 30 atm, and a weight hourly space velocity of 1.7 h^?1. It has been found that the catalyst based on Al-HMS with Si/Al = 10 exhibits the highest activity. Thus, in the hydrogenation of a model mixture containing 150 and 400 ppm of sulfur, the conversion of toluene at 240°C was 22.2 and 10.9 wt %, respectively. In the presence of this catalyst, the concentration of aromatic hydrocarbons in the hydrotreated diesel fraction decreased from 28.4 to 6.8 wt %, and the sulfur content decreased from 45 to 5 ppm.     

Hydroisomerization of n-heptane on Pt promoted phosphomolybdate catalysts

Phospbomolybdate （PMo） with varying Mo loadings ranging from 5-30 wt% on alumina were prepared by incipient wetness impregnation method. 0.5 wt% of Pt was further loaded in order to prepare the bifunctional （metal-acid） Pt-PMo/Al2O3 catalysts. Thus prepared catalysts showed very high catalytic activities for n-heptane hydroisomerization compared with Pt impregnated MoO3 catalysts supported either on Al2O3 or on AIPO4. The conversion of n-heptane increased with Mo loading up to 20 wt% and slightly decreased with further Mo loading. However, the selectivity towards isomers showed an increasing trend up to 30 wt% of Mo in the catalyst. A relationship between catalytic activity and acidic strength was established in the present study.     

Selective hydrocracking of distillates from paraffinic crudes on bifunctional catalysts

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 6, pp. 4–6, June, 1990.     

Mesoporous aluminosilicates as components of gas oil cracking and higher-alkane hydroisomerization catalysts

Mesoporous aluminosilicates with a Si/Al ratio of 5 to 20, a pore diameter of 30 to 84 Å, and a specific surface area up to 1030 cm³/g have been prepared using hexadecylamine and Pluronic P₁₂₃ as templates. These materials exhibit high activity in the cracking of hydrotreated vacuum gas oil. Bifunctional catalysts derived on their basis have high selectivity in the hydroisomerization of hexadecane.     

Hydrogenation of aromatic hydrocarbons in the presence of dibenzothiophene over platinum-palladium catalysts based on Al-SBA-15 aluminosilicates

The hydrogenation of a 2-methylnaphthalene solution in n-heptane in the presence of dibenzothiophene (400 ppm in terms of sulfur) over Pt-Pd catalysts containing Al-SBA-15 mesoporous aluminosilicates has been studied. Supports for the catalysts contained 35 wt % Al-SBA-15 and 65 wt % γ-Al₂O₃. The Pt and Pd contents of the catalysts was 0.25 and 1.0 wt %, respectively. Experiments with the model feedstock were conducted in an autoclave at 240–260°C, an initial hydrogen pressure of 30 atm, and a substrate/metal weight ratio of 30. It has been found that a catalyst based on Al-SBA-15 with Si/Al = 5 exhibits the highest activity under poisoning with 400 ppm sulfur. Thus, the conversion of 2-methylnaphthalene at 260°C after 3 h was 85% with the selectivity for methyltetralins of 97%. The dearomatization of a hydrotreated diesel fraction with 45 ppm sulfur at 260°C at a pressure of 30 atm and a space velocity of 2.4 h^?1 has made it possible to decrease the total aromatic content, in particular reduce the concentration of polycyclic aromatic compounds to a level of less than 1 wt %.     

Pt-M双金属双功能轻质烷烃异构化催化剂的研究进展

Pt-M双金属双功能异构化催化剂不仅可降低Pt的用量,并且可以改善催化剂的性能和使用寿命。介绍了双功能异构化催化剂的催化反应机理,综述了掺杂不同种类非贵金属M后的Pt双功能异构化催化剂的最新研究进展,根据载体的不同主要包括负载Pt-M的HY分子筛催化剂、负载Pt-M的超稳Y沸石催化剂、负载Pt-M的硅磷酸铝分子筛催化剂、负载Pt-M的Hβ分子筛催化剂、负载Pt-M的丝光沸石催化剂、负载Pt-M的固体超强酸催化剂等。对Pt-M双金属双功能催化剂的发展方向进行了预测,低Pt用量、低温且高活性是未来双金属双功能异构化催化剂的主要发展趋势。     

胶溶剂对完全液相法制Cu-Zn-Al双功能催化剂性能的影响

以硝酸铝为铝源,分别用乙酸、硝酸和磷酸做胶溶剂,采用完全液相法制备了Cu-Zn-Al双功能催化剂;利用浆态床反应装置对其合成气一步法制二甲醚的催化活性进行了评价,并通过NH3-TPD,XRD,XPS等方法对催化剂进行表征。研究表明,胶溶剂能调变催化剂的表面酸性和表面元素组成,以乙酸作胶溶剂所制催化剂拥有最多的中强酸,对二甲醚选择性最好。     

Pd／NiSMM对正辛烷异构化反应的催化作用

考察了正辛烷在钯负载的ＮＩＳＭＭ、ＨＭ、ＨＹ和ＣＬＳ催化剂上异构化的催化活性和产物分布以及Ｐｄ／ＮｉＳＭＭ催化活性的稳定性和抗硫、抗氛中毒能力，并用催化剂的酸性质对试验数据进行了解释。试验结果表明，Ｐｄ／ＮｉＳＭＭ具有优良的正辛烷异构化催化活性、选择性和稳定性，其抗硫、抗氛中毒能力也很强，抗硫中毒能力优于Ｐｄ／ＨＭ催化剂。     

MCM-41分子筛载体在镍基催化反应中的研究进展

MCM-41介孔分子筛具有较高的比表面积、规整的孔道结构和可调的孔径等特性,可作为催化剂优良的载体,在镍基催化反应中应用广泛。介绍了MCM-41介孔分子筛在镍基催化加氢、加氢脱硫、CH4/CO2重整等反应中的研究进展,并展望了介孔分子筛MCM-41在催化领域中的研究方向。     

新型双孔球形介孔材料用于乙烯聚合催化剂

以喷雾干燥法制备了球形介孔材料,并以该球形介孔材料为载体制备了乙烯聚合催化剂。利用N_2吸附-脱附、XRD、SEM等方法对介孔材料进行了表征,并通过乙烯淤浆聚合考察了催化剂的聚合性能。表征结果显示,自制的球形介孔材料具有较大的比表面积,孔径呈双峰分布,存在典型的介孔结构。球形介孔材料制备的催化剂的球形度略好于参比载体制备的催化剂,粒径分布略宽。球形介孔材料制备的催化剂的催化效率和氢调性能优于相同条件下参比载体制备的催化剂,聚合过程平稳,催化活性高,制备的聚乙烯产品形态好,聚合物中粒径在75μm以下的细粉含量低。     

二甲醚水蒸气重整制氢双功能催化剂研究进展

从提高催化剂酸中心、金属中心的利用率和调整酸中心与金属中心接近性三方面,综述了国内外二甲醚水蒸气重整制氢双功能催化剂的研究现状,重点阐述了助剂改性、载体改性、制备方法及反应器对双功能催化剂性能的影响,并展望了未来开发双功能催化剂的研究方向。     

介孔氧化铝制备方法对其载体及催化剂性能的影响

分别采用醇铝法和沉淀法制备氧化铝,借助N_2物理吸附-脱附、XRD和SEM等技术对试样进行了表征,并对制备的载体进行对比。表征结果显示,醇铝法制备的拟薄水铝石纯度及结晶度更高,杂质少;小孔氧化铝孔径分布峰集中且峰形尖锐,峰宽较窄;大孔氧化铝孔径分布峰更宽甚至消失;氧化铝由粒径均匀且完整度高的球形颗粒聚集而成;小孔氧化铝载体孔径分布集中,没有大孔;而大孔氧化铝载体除介孔外还含有许多大孔。将两种方法制得的大孔氧化铝载体制备成催化剂,以渣油和蜡油混合油为原料,在氢分压15.5 MPa、氢油体积比650∶1、反应温度390℃、液态空速0.5 h~(-1)的条件下对催化剂进行评价。评价结果显示,醇铝法制备的催化剂具有较为优异的加氢脱硫、加氢脱氮、加氢脱残炭及加氢脱金属活性。     

Bimetallic sulfide catalysts based on mesoporous organic supports in the hydrofining of light cycle oil

Bimetallic sulfide hydrodearomatization–hydrodesulfurization catalysts based on mesoporous organic supports made of phenol-formaldehyde resins (MPF) and porous aromatic frameworks (PAFs) have been synthesized. The catalysts exhibit high activity in the hydroconversion of light cycle oil: the sulfur content decreases from 3500 to 390 ppm within 8 h of reaction at a hydrogen pressure of 5 MPa and a temperature of 380°C.     

正构烷烃临氢异构化反应研究进展

综述了对正构烷烃临氢异构化反应进行的研究.介绍了正构烷烃临氢异构化催化剂,主要是金属/固体酸构成的双功能催化剂.讨论 了正构烷烃临氢异构化反应理论,包括传统的择形催化理论、孔口催化和钥匙-锁催化理论 .重点总结了正构烷烃在双功能催化剂上的异构化反应机理,包括单分子反应机理和双分子 反应机理.详细讨论了影响双功能催化剂正构烷烃临氢异构化反应性能的主要因素.还综述 分析了碳氧化物和部分还原的氧化物异构化催化剂的研究进展及存在的问题.指出了正构烷烃临氢异构化催化剂的发展趋势.     

介孔ZnO制备方法对ZnO负载的Pd催化剂甲醇水蒸气重整性能的影响

以三嵌段高聚物F-127为模板剂,采用水热法和沉淀法分别合成了介孔氧化锌m-ZnO(H)和m-ZnO(C),再以沉积-沉淀法制备m-ZnO负载的Pd基催化剂,并考察了其甲醇水蒸气重整制氢反应性能。利用XRD、FT-IR和BET等手段对载体及催化剂进行了表征。发现不同制备方法所制得的m-ZnO的性能有较大差异,其中m-ZnO(H)具有较大的BET比表面积、孔容和孔壁厚度。因此,以m-ZnO(H)为载体的Pd基催化剂对甲醇水蒸气重整制氢反应具有较高的催化活性、氢气产率和二氧化碳选择性。