无黏结剂Zn/ZSM-11催化剂的异丁烷和二甲醚芳构化催化性能

采用常规浸渍法制备系列Zn/ZSM-11催化剂,对其进行N2吸附-脱附和Py-IR表征,并用于催化异丁烷和二甲醚芳构化反应。结果表明,氧化铝成型Zn/ZSM-11催化剂(Cat-A)的BET比表面积和孔体积最大,无黏结剂Zn/ZSM-11分子筛催化剂(Cat-C)的最小;氧化硅成型Zn/ZSM-11催化剂(Cat-B)的微孔体积与Cat-C的差别不明显。催化剂的B酸量及B酸/L酸顺序为:Cat-ACat-BCat-C。与Cat-A和Cat-B相比,Cat-C上异丁烷转化率和产物中芳烃收率最高。     

Pt/Pt-Ce/γ-Al2O3催化氧化甲苯研究

通过等体积浸渍法制备单贵金属Pt/γ-Al₂O₃和双金属Pt-Ce/γ-Al₂O₃催化剂,考察Ce对催化剂活性的影响,确定催化剂最优配比。结果表明,当Pt的负载量为质量分数0.5%时,Pt/γ-Al₂O₃催化活性最高;当Pt的负载量为质量分数0.2%,Ce的负载量为质量分数1.0%时,Pt-Ce/γ-Al₂O₃催化剂的催化活性最高。Pt-Ce/γ-Al₂O₃催化剂的甲苯转化率高于Pt/γ-Al₂O₃催化剂。随着Pt负载量增大,催化剂孔容、孔径减小。粉体式催化剂性能优于整体式催化剂,但差别不大;Ce的添加有助于催化剂活性的提升。     

Methane aromatization using Mo-based catalysts prepared by microwave heating

Mo/HZSM-5 and Cu–Mo/HZSM-5 catalysts for the non-oxidative aromatization of methane have been prepared by microwave heating method. The effects of Mo loading, the molar ratio of Cu/Mo and preparation method on the catalytic performance of catalysts were studied. The results were compared with those for the methane aromatization over catalysts prepared by conventional heating. Both two kinds of catalysts have the maximum methane conversion when the Mo loading is 6%. The catalysts prepared by microwave heating exhibited higher selectivity to benzene than that prepared by conventional heating. The addition of metal Cu to Mo/HZSM-5 catalyst prepared by microwave heating enhanced the lifetime of catalyst, and gave rise to a little increase in methane conversion. The molar ratio of Cu/Mo influenced the methane conversion, and the maximum value was attained when Cu/Mo = 0.05, whereas no significant influence on the benzene selectivity was observed with the increase molar ratio of Cu/Mo. N₂ adsorption results showed that the catalysts prepared by microwave heating have the larger surface area and the similar pore volume compared with the catalysts prepared by conventional heating. This fact revealed that the more Mo species located on the outer surface of catalysts prepared by microwave heating is the main reason why they have better catalytic performance. XRD analysis indicated that the Mo species are highly dispersed on HZSM-5 zeolite. The addition of Cu influenced the dispersion. The actual active phase Mo₂C can be identified on the catalyst surface after reaction. TEM analysis revealed the carbonaceous deposition to have the form of carbon nanotube after reaction, with a uniform size range of 10–20 nm. TG analysis indicated that carbonaceous deposition on the catalysts prepared by microwave heating is lower than that by conventional heating, and the metal Cu further prompts the stability of catalyst. Most of the carbonaceous deposition on catalysts prepared by microwave heating is formed at low temperature and it is easy to burn-off. Coke accumulation at high temperature is the main reason of catalyst deactivation. The carbonaceous deposition formed on the catalysts for non-oxidative aromatization of methane is different from those formed on the catalysts for partial oxidation of methane.     

氯的脱除对丙烷脱氢PtSnNa/Al2O3催化剂结构的影响

考察了氯的脱除对丙烷脱氢铂锡催化剂结构和反应性能的影响,并采用XRD、N₂吸脱附、TPR、NH₃-TPD、TEM和Raman等方法进行表征。结果表明,氯的脱除温度显著影响催化剂的酸性、孔体积、比表面积、孔径和Pt颗粒尺寸。随着处理温度的提高,催化剂酸性、比表面积、孔体积都呈现下降的趋势,平均孔径增加,Pt颗粒的烧结程度加剧。随着处理温度的增加,催化剂初活性逐渐降低,丙烯选择性增加,稳定性出现先增加后降低趋势。研究表明,氯的较佳的脱除温度为540℃,催化剂具有很好的脱氢性能和稳定性,收率最高。     

级孔Pt-Ni/ZSM-5对木质素衍生物加氢脱氧性能研究

利用等体积共浸渍法制备了级孔ZSM-5分子筛负载Pt-Ni双金属催化剂,并系统研究了不同Pt/Ni比对愈创木酚和二苯并呋喃二元混合物加氢脱氧反应性能的影响。采用XRD、N₂-BET、SEM、TEM和H₂-TPR对Pt-Ni催化剂的形貌和结构进行了表征。Ni掺入量较少时（1%和3%,质量分数）,有利于促进活性金属的分散,增强Pt-Ni双金属之间的协同作用;当Ni掺入量增加到5%时,活性金属出现较严重的团聚。二元混合物加氢脱氧实验结果表明与单金属Pt/HZ-75相比,双金属Pt-Ni/ZSM-5催化剂均表现出优异的加氢脱氧催化活性,Ni的引入显著提高了反应转化速率,并提高了产物中联环己烷的选择性。随着Pt/Ni比的降低,Pt-Ni催化剂的活性逐渐增加,而联环己烷选择性先升高后降低。Pt-3Ni/HZ-75催化剂在3 MPa、260℃下表现出最佳的催化活性和联环己烷选择性,反应4 h后转化率达到100%,联环己烷选择性达到43%。     

器外预硫化催化剂加氢脱酸性能研究

为探索器内硫化与器外预硫化催化剂的催化活性,采用等体积浸渍法制备同一批次镍-钨氧化态催化剂,分别采用器内硫化与器外预硫化得到3种不同的催化剂,考察3种新鲜催化剂的物化性质、催化活性和使用后催化剂的物化性质。结果表明：随着催化剂上硫化物负载量增加,预硫化催化剂的表观密度增加,比表面积、孔容、平均孔径均降低,同时预硫化催化剂在各个孔径范围内的分布均降低;3种催化剂中高负载硫的器外预硫化催化剂上W ⁴⁺态金属和NiWS活性相原子分数最高,器内硫化催化剂次之,低负载硫的器外预硫化催化剂最低;在反应压力为3.0 MPa、空速为1.0 h ^-1、氢油体积比为400∶1条件下,以绥中常二线、减三线馏分油为原料在不同反应温度下评价催化剂的活性,高负载硫的器外预硫化催化剂的脱酸、脱硫、脱氮活性最高,器内硫化催化剂次之,低负载硫的器外预硫化催化剂的催化活性最差。     

氧化铝煅烧温度对丙烷脱氢催化剂性能的影响

针对丙烷脱氢催化剂用氧化铝作为载体时存在的孔结构与表面酸性调节的问题,开发了以海藻酸盐为黏合剂,采用挤出滚圆方法,制备了大孔球形氧化铝颗粒,并以此作为载体负载Pt、Sn活性组分制备了丙烷脱氢催化剂,研究了氧化铝载体煅烧温度对催化剂晶型、孔道结构、表面酸性、H2还原性能与丙烷脱氢性能的影响.实验结果表明:随氧化铝载体煅烧...     

Effect of halogen anion on hexane aromatization activity of Pt/KL catalysts

Potassium salts were added to the catalyst prepared by ion exchange of KL with [Pt(NH3)₄]Cl₂ and the effect of their counter anion on the activity and selectivity for hexane aromatization was studied. The catalyst to which KF was added showed the highest activity and selectivity for benzene formation; methylcyclopentane and hydroisomerization products were negligible. Although the catalyst with KCl added also exhibited excellent performance, the catalysts with KBr or KI added gave rise to low hexane conversion and benzene yield. Infra-red spectra of adsorbed CO revealed that the presence of the low frequency C-O stretching band is closely related to catalytic performance of the Pt/KL series catalysts. The electron-rich Pt site formed through the interaction with KF or KCl may be responsible for the high activity and selectivity for hexane aromatization.     

PtAu/ZrO_2催化甘油选择性制备乳酸

采用溶胶-沉积法制备了Pt Au/ZrO_2系列催化剂,在惰性气体气氛下用于催化甘油选择性制备乳酸。研究不同反应温度下,不同单金属负载和不同比例Pt Au双金属负载催化剂的催化活性以及不同气氛下催化剂重复使用性能,对催化剂进行BET、AAS和TEM等表征。结果表明,在浓度1.1 mol·L-1甘油水溶液10 m L、(1∶1)Pt Au/ZrO_2催化剂用量0.132 g、反应温度160℃、氮气压力1.4 MPa和反应时间6 h条件下,甘油转化率90%,乳酸选择性93.7%。催化剂重复使用性能实验验证了氧气气氛下催化剂活性保持良好。     

Pt/ZSM-35催化长链正构生物烷烃加氢裂化/异构化制航空煤油

以生物质油加氢脱氧得到的长链正构生物烷烃为原料，考察了H-MCM-49、H-ZSM-5、H-ZSM-22和 H-ZSM-35这4种不同分子筛催化剂的物化性质及其加氢裂化/异构化制生物航空煤油的性能。在此基础上，以H-ZSM-35分子筛为载体，制备并表征了一系列低负载量（0.1%、0.2%和0.3%）的Pt/ZSM-35双功能催化剂，以长链正构生物烷烃转化率、C₉~C₁₆产物选择性、生物航空煤油收率和异正比为指标，对其加氢裂化/异构化制生物航空煤油反应性能进行了评价，并对反应工艺条件进行优化。结果表明：H-ZSM-35的强酸中心强度高、酸量大，其结构中较小的孔口和较大的球型笼使其具有一定的容烃量和较好的择形性能，0.1%~0.3% Pt负载后， Pt/ZSM-35双功能催化剂表现出很好的加氢裂化/异构化活性和选择性。采用0.1% Pt/ZSM-35双功能催化剂在反应条件为320℃、1MPa、0.7h^-1、氢油比840∶1时，长链正构生物烷烃的转化率为84.3%，生物航空煤油收率达41.1%，产物异正比为1.34。81h长运转测试结果表明，该催化剂具有很好的稳定性。     

粘合剂和钡对Pt/L催化剂性能的影响

L分子筛芳构化催化剂与传统的双功能重整催化剂相比,链烷烃芳构化活性和选择性高得多。粘合剂影响L分子筛催化剂的强度、芳构化活性和选择性。Pt/K BaL催化剂比Pt/KL催化剂的芳构化活性和选择性高。钡含量影响Pt/K BaL催化剂的芳构化活性和选择性。微反结果表明,自制的Pt/KL和Pt/K BaL催化剂比文献报导的载铂L分子筛催化剂的芳构化活性和选择性高,100mL装置评价结果也证明两种自制催化剂具有很高的芳构化活性和选择性。     

液相原位还原法制备钯基催化剂

采用液相原位还原法制备Pd/α-Al2O3催化剂,并应用于CO氧化偶联合成草酸二甲酯反应。对比实验发现,甲醛液相原位还原法制得的Pd基催化剂具有优异的催化活性,当Pd负载质量分数低至0.1%时,催化剂仍表现出较高的活性和稳定性。采用XRD和BET等对催化剂及载体进行表征,结果表明,催化剂活性与载体的比表面积、孔容和孔径没有必然联系。通过TEM发现,0.1%-Pd/α-Al2O3催化剂中的主要活性组分Pd具有较小的颗粒和较高的分散性,通过HRTEM发现,液相原位还原法制备的催化剂能够有效暴露出Pd(111)晶面。     

柴油车DOC催化剂Pt/CeZrO2载体的制备及影响

分别用氢氧化钠（NaOH）、草酸（H₂C₂O₄）和碳酸钠（Na₂CO₃）为沉淀剂制备CeZrO₂固溶体,并以此为载体制备了Pt/CeZrO₂柴油车DOC催化剂,通过XRD、BET、H₂-TPR和催化氧化反应等手段对催化剂物理化学特性进行研究。结果发现,以NaOH作为沉淀剂制备的CeZrO₂固溶体比表面积大（68.8 m²·g^-1）、氧活动性强[表面氧耗氢量达1143 μmol·（g cat（^-1],同时贵金属Pt在其表面高度分散,因此制得的Pt/CeZrO₂柴油车DOC催化剂催化效果好,特别是催化氧化碳氢化合物（C₃H₆）,T₉₀比H₂C₂O₄和Na₂CO₃为沉淀剂制备的Pt/CeZrO₂催化剂降低了将近40℃。另外载体制备方式对催化剂抗硫性影响也十分显著。故选择一种合适的载体沉淀剂可使制得的DOC催化剂具备良好的活性及抗硫性。     

磷改性对氯化Ni-W/SiO2/γ-Al2O3降烯烃催化剂性能的影响

采用氯化处理后的硅铝载体，通过等体积浸渍法分别制备了磷改性前后的两种Ni-W/硅铝催化剂。利用FR/IR-560和Digisorb-2400物理吸附仪对两种催化剂的酸度、比表面积、孔径和孔容等进行了表征，同时利用荧光指示剂吸附法对磷改性前后催化剂降烯烃的性能进行了考察。结果表明，磷改性使催化剂的B酸中心数量增加了0.02 mmol·g^－1，而B酸中心的增加有利于双分子的氢转移反应,避免反应过程中催化剂表面的积炭。在催化剂活性方面，磷改性使催化裂化汽油中的烯烃含量降低了3.06个百分点，同时提高了产品油的液体收率；从产品分布看，含磷催化剂的液体产品中异构烷烃和芳烃比例均有所提高，说明磷的加入增加了异构化和芳构化的反应活性。     

Preparation of heavy oil hydrotreating catalyst from spent residue hydroprocessing catalysts

In recent years, increasing emphasis has been placed on recycling spent hydroprocessing catalysts due to environmental regulations which list them as hazardous waste materials. In the present work, the recycling of spent residue hydroprocessing catalysts that contained high levels of vanadium was investigated by using them in the preparation of active new hydrotreating catalyst after subjecting them to different treatments such as decoking, acid-leaching and hydrothermal treatment. Catalyst extrudates containing different levels of V, Mo and Ni on Al₂O₃ were prepared by mixing the spent catalyst powder with boehmite in different proportions followed by peptization, kneading and extrusion. The prepared catalyst extrudates were characterized by chemical analysis and surface area and porosity measurements. The HDS and HDM activities of the catalysts were tested using Kuwait atmospheric residue as feed and compared with that of a reference HDM catalyst. Partial leaching of vanadium from the spent catalyst opened up the pores, and the catalyst prepared by mixing the metal-leached spent catalyst (MLSC) with boehmite had higher surface area and pore volume and showed higher hydrotreating activity than that prepared from unleached spent catalyst. Hydrothermal treatment of the spent catalyst increased its porosity and surface area. Catalysts prepared from hydrothermally treated spent catalyst (HTSC) had higher surface area and pore volume and showed higher HDM and HDS activities than that prepared from the spent catalyst without hydrothermal treatment. The catalysts prepared from the treated spent catalysts also exhibited substantially higher HDM and HDS activities than the reference commercial HDM catalyst. The results indicate that spent catalysts containing high levels of vanadium together with Mo and Ni on Al₂O₃ can be used in the preparation of active HDM/HDS catalysts, and thereby, their environmental problem can be reduced.     

Co-Mo-Ni-W/γ-Al2O3柴油加氢精制催化剂的研制

采用浸渍法制备Co-Mo-Ni-W/γ-Al₂O₃柴油加氢精制催化剂,考察了扩孔剂及焙烧温度对载体物化性能的影响和浸渍液的配制方法对其稳定性的影响。并考察了催化剂第1次浸渍后的焙烧温度以及3种催化剂的加氢精制活性。实验结果表明,在载体制备过程中适量加入扩孔剂,可得到孔分布集中、比表面积和孔容适中的载体;载体于550 ℃焙烧时,可制备出具有良好的孔分布和较高机械强度及较大的比表面积的催化剂;在低温条件下配制的浸渍液具有良好的稳定性和可溶性;催化剂第1次浸渍后于450 ℃条件下焙烧,可使催化剂中的各活性组分均匀分布于载体上; 通过催化剂的加氢活性评价,3种催化剂均具有良好的柴油加氢精制活性和工业应用前景。     

ZSM-5/γ-Al2O3质量比对FCC轻汽油异构化/芳构化性能影响

通过调变ZSM-5分子筛与γ-Al₂O₃质量比,采用等体积浸渍法制备系列FCC轻汽油异构化/芳构化催化剂。本文采用X射线衍射（XRD）、N₂吸附脱附、扫描电子显微镜（SEM）、氨气程序升温脱附（NH₃-TPD）、红外光谱（IR）和吡啶红外光谱（Py-IR）等手段对其进行表征,并以乌鲁木齐石化醚后C₅掺杂液化石油气（LPG）为原料对催化剂异构化/芳构化性能进行评价。实验结果表明,ZSM-5分子筛与γ-Al₂O₃质量比的调变可以改变催化剂的酸性质及孔结构性质。在反应温度380℃、反应压力1.0MPa、反应空速1.0h^-1、氢/油体积比100、LPG进量4.4g/h的条件下,ZnLa/ZSM-5/γ-Al₂O₃-1异构化/芳构化产物与反应原料相比,烯烃体积分数降低27.49%、异构烷烃体积分数增加15.87%、芳烃体积分数增加3.97%,辛烷值损失3.38个单位,产品收率高达89.90%,实现了异构化/芳构化大幅降烯烃保辛烷值的目标。     

活性氧化铝在FCC催化剂中的应用研究

采用N^₂吸附法、IR和XRD等手段研究了活性氧化铝用于催化裂化(FCC )催化剂中的性能。结果表明,在FCC催化剂制备及应用条件下,活性氧化铝保持比较稳定的比表面积、孔容和酸性等性能。磷易与活性氧化铝作用,分子筛与磷的作用存在一个逐步平衡的过程;氧化铝有利于改善基质的孔结构;对以铝溶胶为粘结剂制备的催化剂进行磷改性处理,催化剂基质与活性组分分子筛上的磷含量基本相当。     

Sulfur- and water-tolerance of Pt/KL aromatization catalysts promoted with Ce and Yb

Different Pt/KL catalysts containing rare earth (RE; Ce and Yb) promoters were prepared by two techniques, incipient wetness impregnation (IWI) and vapor phase impregnation (VPI). The catalysts were tested for the activity and the selectivity of n-hexane aromatization to benzene under clean, sulfur-containing, and water-containing feeds at 500 °C. It was observed that the catalysts prepared by the VPI technique exhibited much higher activity and selectivity than those prepared by IWI. It was also found that although under clean conditions, the addition of Ce or Yb caused a decrease in activity, in the presence of sulfur the addition of Ce and to a lesser extent Yb, significantly inhibited catalyst deactivation.

The influence of water in the feed was investigated by contacting the catalysts for 1 h to a feed containing 3 mol.% water. After this treatment, all the catalysts exhibited a significant activity loss. This loss was more pronounced for the catalyst prepared by the VPI method. The catalyst prepared by IWI already had suffered a significant deactivation before the water treatment, so the activity drop was not so pronounced. The sample prepared by VPI not only showed a drop in activity immediately after the water treatment but it became more susceptible to deactivation afterwards. By contrast, the Ce-promoted catalyst showed a more stable activity after the water treatment.

All catalysts were characterized before and after reaction by a number of techniques. In agreement with previous studies, FT-IR of adsorbed CO and chemisorption results indicated that the VPI method resulted in higher Pt dispersion than that obtained by the IWI method. After reaction in the presence of sulfur, the Ce-promoted Pt/KL catalyst showed a higher resistance to metal agglomeration and a lower rate of coke formation than the unpromoted Pt/KL. On all the catalysts, the amount of carbon deposits was greater in the presence of sulfur and after exposure to water vapor than under the reaction with clean feeds. This difference is explained in terms of metal particle growth and location in the zeolite.     

MnOx/Pt/Al2O3 catalysts for CO oxidation in H2-rich streams

The catalytic activity of Pt on alumina catalysts, with and without MnO_x incorporated to the catalyst formulation, for CO oxidation in H₂-free as well as in H₂-rich stream (PROX) has been studied in the temperature range of 25–250 °C. The effect of catalyst preparation (by successive impregnation or by co-impregnation of Mn and Pt) and Mn content in the catalyst performance has been studied. A low Mn content (2 wt.%) has been found not to improve the catalyst activity compared to the base catalyst. However, catalysts prepared by successive impregnation with 8 and 15 wt.% Mn have shown a lower operation temperature for maximum CO conversion than the base catalyst with an enhanced catalyst activity at low temperatures with respect to Pt/Al₂O₃. A maximum CO conversion of 89.8%, with selectivity of 44.9% and CO yield of 40.3% could be reached over a catalyst with 15 wt.% Mn operating at 139 °C and λ = 2. The effect of the presence of 5 vol.% CO₂ and 5 vol.% H₂O in the feedstream on catalysts performance has also been studied and discussed. The presence of CO₂ in the feedstream enhances the catalytic performance of all the studied catalysts at high temperature, whereas the presence of steam inhibits catalysts with higher MnO_x content.