稀士助剂Y对甲烷芳构化反应催化剂Y—Mo／HZSM—5表面性质的影响

用吡啶－ＴＰＤ实验和异丙醇分解反应研究了稀土助剂Ｙ对甲烷芳构化反应催化剂Ｍｏ／ＨＺＳＭ－５表面性质的影响，说明了稀土Ｙ对Ｍｏ／ＨＺＳＭ－５催化剂的添加增强了催化剂表面的酸性，从而促进了甲烷的活化，提高了甲烷转化率。     

工业芳构化催化剂中γ－Al_2O_3对分子筛酸性的影响

用重量吸附法测得ＨＺＳＭ－５分子筛原粉、γ－Ａｌ２Ｏ３和工业用芳构化催化剂ＨＺＳＭ－５的酸量和强度。实验发现ＨＺＳＭ－５原粉和工业催化剂的酸量很接近，而Ａｌ２Ｏ３的酸量要比原粉低得多，强酸只占原粉的１０％左右。用红外吸附法测得原粉的Ｂ酸／Ｌ酸相对含量为催化剂的４倍左右，实验表明，Ａｌ２Ｏ３对分子筛的酸性有较大影响，主要增加了Ｌ酸。     

钇对甲烷芳构化催化剂Mo／HZSM—5性能影响的研究

研究了稀土钇的含量对Ｍｏ／ＨＺＳＭ－５催化剂的活性和选择性的影响，发现稀土钇的加入，不同程度上提高了Ｍｏ／ＨＺＳＭ－５的活性和选择性。特别是，当Ｙ／Ｍｏ＝０．０４时，活性最佳。甲烷在１０２３Ｋ芳构化反应，转化率达１９．６％，苯的选择性达９６．５％，且活性较稳定。     

Zn—Cr—A／HZSM—5催化剂CO＋H2高压反应的研究

研究了Ｚｎ－Ｃｒ－Ａ／ＨＺＳＭ－５复合催化剂在高压不同反应压力条件下的反应结果，结果显示：该催化剂具有较好的ＣＯ及Ｃ＾＋５选择性，其最佳反应压力为４．０５３ＭＰａ。     

ZA—5型氨合成催化剂的研究：基本物化特性与表征

我国Ｆｅ１－ｘＯ基催化剂体系的创立为熔铁催化剂的发展开辟了一条新途径。经多年努力,在Ｆｅ１－ｘＯ催化剂体系和Ａ３０１型催化剂基础上又开发成功低温高活性的ＺＡ－５型催化剂,运用ＸＲＤ、ＸＰＳ、ＳＥＭ、Ｍｏｓｓｂａｕｅｒ、Ｎ２ＴＰＤ、ＴＧ－ＤＴＧ和ＢＥＴ及化学吸附等方法研究了ＺＡ－５型催化剂的化学组成、晶体结构、表面组成和表面结构等基本物化特性。     

改性ZSM－5对甲醇芳构化催化活性的研究

探讨了不同金属离子对ＺＳＭ－５分子筛的改性、分子筛的硅铝比、焙烧及反应温度对分子筛在甲醇芳构化中催化活性的影响．并找出了对甲醇芳构化催化活性较高的改性ＺＳＭ－５分子筛及适宜的工艺条件。     

色淀化剂对色酚类偶氮色淀颜料性能的影响

本文研究了以２Ｂ酸（４－氯－２－氨基－５－甲基－苯磺酸）为重氮组份，色酚ＡＳ－ＯＬ（Ｎ－邻甲氧基苯基－３－羟基－２－萘甲酰胺）为偶合组分，采用Ｃａ２＋、Ｓｒ２＋、Ｂａ２＋、Ｍｇ２＋、Ｍｎ２＋、Ｚｎ２＋等金属盐为色淀化剂制备色淀颜料。观察不同色淀化剂对色淀颜料的色光、晶型及耐热稳定性的影响。结果表明，采用不同金属盐为色淀化剂，对色淀颜料的色光、色力及耐热稳定性有明显影响。     

Li3Zn0.5SiO4水基溶胶-凝胶法合成及其离子导电性

用水基溶胶－凝胶法制备了锂离子导体Ｌｉ３Ｚｎ０．５ＳｉＯ４的纯相。实验中对干凝胶进行了ＴＧ－ＤＴＡ分析,ＸＲＤ谱结果表明形成了与高温Ｌｉ３ＰＯ４结构相关的Ｌｉ３Ｚｎ０．５ＳｉＯ４晶相,ＴＥＭ结果则显示晶粒尺寸为５０ｎｍ左右,应用交流阻抗谱技术进行了样品烧结体的电性能测试。     

甲烷芳构化反应催化剂Ｍｏ-Ｍ／ＨＺＳＭ-５表面性质的研究

对甲烷芳构化催化剂Ｍｏ-Ｍ／ＨＺＳＭ-５进行了异丙醇分解、ＮＨ３-ＴＰＤ-ＭＳ、积炭量测定表征,其结果均与芳构化性能有关。芳烃收率高,稳定性好,积炭量较少,而且具有相当量的酸量和一定量强酸量及较强的脱氢中心。     

无机氟改性的HZSM－5分子筛催化1，2，4－三甲苯与甲醇烷基化合成1，2，4，5－四甲苯的研究

用不同浓度的ＮＨ_４Ｆ对ＨＺＳＭ－５分子筛进行改性制成偏三甲苯－甲醇烷基化反应的催化剂,考察反应时间、改性剂浓度、焙烧温度对其催化性能的影响。结果发现,无机氟改性使ＨＺＳＭ－５分子筛对偏三甲苯－甲醇烷基化合成均四甲苯反应的活性、选择性及催化剂的稳定性都有良好的促进作用,并且改性后的ＨＺＳＭ－５分子筛加入粘合剂制成的催化剂仍具有良好的催化性能。采用ＳＥＭ、ＩＲ及ＴＰＤ等方法测试无机氟改性后ＨＺＳＭ－５分子筛结构及酸性的变化。     

金属负载HZSM-5催化剂上乙烯芳构化反应研究

报道了15种负载不同金属的HZSM-5催化剂对乙烯芳构化的催化效果,以Ga(Zn)/HZSM-5催化剂为例,研究了载体酸性、金属含量、反应温度等因素对催化剂催化性能的影响。并对金属负载的HZSM-5催化剂在乙烯芳构化反应中的作用进行了深入研究讨论。     

The effect of intermetallic hydrogen acceptor on catalytic aromatization of propane

The effect of the hydride-forming intermetallic compound Zr₂Fe on the aromatization of propane over high-silica zeolites of CVM type (Russian equivalent of ZSM-5) modified by Zn, Ga or Pt cations has been investigated. Aromatics yield and selectivity of aromatization are shown to increase essentially as a result of releasing hydrogen elimination by the intermetallic acceptor. The effect of hydrogen acceptor on propane conversion and product distribution appeared to be different depending on the composition of the catalyst used. Possible changes in the reaction mechanism in hydrogen removal conditions are discussed.     

The effect of Ga and Zn over HZSM-5 on the transformation of palm fatty acid distillate (PFAD) to aromatics

The catalytic conversion of PFAD (palm fatty acid distillate) to aromatics has been studied over HZSM-5, Ga/HZSM-5, and Zn/HZSM-5 catalysts. The presence of both Ga and Zn promoted the aromatization of PFAD. The higher aromatics yield of Zn/HZSM-5 was achieved by the presence of two zinc species; exchanged Zn^2 + promoting the dehydrogenation of paraffins and ZnO promoting the decarboxylation of oxygenates. The shifting from decarbonylation over the Brønsted acid site of the parent HZSM-5 to decarboxylation over ZnO preserved the Brønsted acid site for aromatization, thus increasing the aromatics yield.     

Aromatization activity of gallium containing MFI and TON zeolite catalysts in n-butane conversion: Effects of gallium and reaction conditions

A kinetic study of n-butane conversion over acidic and gallium (Ga) containing MFI and TON zeolites has revealed that Ga active sites create a new pathway for aromatics formation via dehydrogenation reaction steps. This pathway does not involve bulky bimolecular hydrogen transfer steps of the aromatization process over acidic zeolites, and, as a consequence, leads to considerably higher enhancement of the aromatization activity of the one-dimensional TON catalyst when compared to the three-dimensional MFI catalyst. This finding highlights fundamentally different spatial requirements for alkane aromatization over acidic and Ga containing zeolites and indicates that the zeolites with severe spatial constraints could become very selective catalysts for alkane aromatization after their modification with Ga. It is anticipated that these results will initiate the search for new, highly selective aromatization catalysts based on zeolites with different structures. The second important finding of this work is the evolution of the aromatization activity of GaH-TON and GaH-MFI catalysts during n-butane reaction that is likely associated with formation of catalytically active Ga⁺ ions. In our study, this process was completed in about 15 min, i.e. much faster then similar processes that were reported earlier in the literature for the GaH-MFI catalysts. To the best of our knowledge, no data on the evolution of the aromatization activity was reported up to day for the one-dimensional GaH-TON catalysts.     

C_4液化气芳构化制芳烃催化剂的研究

在HZSM-5（SiO2/Al2O3=38）分子筛上,经金属改性制备了碳四液化气芳构化催化剂,并对催化剂进行了表征。在100 mL固定床实验装置上,考察了金属改性对催化剂物化性质、芳构化活性以及稳定性的影响,结果表明,金属改性能显著提高催化剂芳构化活性,由Zn和Ga共同改性的HZSM-5分子筛酸性分布更加合理,并能进一步促进碳四液化气芳构化制芳烃催化剂活性和稳定性的提高。     

Aromatization of n-hexane over Ga,Mo and Zn modified H-ZSM-5 zeolite catalysts

n-Hexane aromatization was investigated at 500 °C on parent and metal (i.e. Ga, Mo and Zn) modified H-ZSM-5 zeolite catalysts. Conversion reached 88% over H-ZSM-5 and was stable. Addition of metal resulted in lower conversion (< 80%). Formation of aromatic compounds was favored on Ga/H-ZSM-5 (> 35%) and Zn/H-ZSM-5 (> 40%) while H-ZSM-5 and Mo/H-ZSM-5 showed higher cracking activity. Gallium and zinc favored aromatization. At 600 °C a decrease in activity with increasing TOS was observed. A decrease in aromatics selectivity was also observed. The aromatics selectivity with increase in TOS of Ga/H-ZSM-5 (43–27%) and Mo/H-ZSM-5 (35–27%) catalysts was higher than for Zn/H-ZSM-5 (46–7%).     

不同载体成型的ZSM-5催化剂上甲醇芳构化反应性能

以ZSM-5分子筛为活性组分,采用不同的氧化物载体挤条制备催化剂,并对催化剂的甲醇芳构化反应性能进行评价。采用X射线衍射、氨程序升温脱附和N₂低温吸附-脱附等方法对催化剂进行表征。结果表明,添加氧化物载体后,催化剂的芳构化反应性能明显提高,催化剂芳构化反应性能与其酸性质有着密切联系,Zn/La-ZSM-5(Al₂O₃)催化剂的芳构化反应性能较好,主要归因于催化剂具有适宜的酸分布和孔结构。在反应压力0.1 MPa、空速0.8 h^-1、反应温度437 ℃和反应时间240 min条件下,轻质芳烃收率为42.36%.     

Aromatization of pentane catalyzed over various metallosilicates

Various metallosilicates were synthesized using a hydrothermal method and characterized by SEM, XRD,²⁹Si MAS NMR, chemical analysis and surface area measurements. These results showed that they had a MFI structure. The pentane aromatization reaction was carried out over these metallosilicates in a continuous flow reactor at 550 °C, He/pentane=3, WHSV=1.5 h⁻¹ and 1 atm. Among the various metallosilicates, [Ga]ZSM-5(20) (52.3%) and [Zn]ZSM-5(40) (37.6%) showed higher aromatic selectivities for pentane aromatization. When [Al] ZSM-5(40) was ion-exchanged with gallium nitrate and zinc chloride, the selectivities for aromatics increased from 23.0% to 35.5% and to 32.7%, respectively. The Si/metal mole ratios of [Ga]ZSM-5 and [Al]ZSM-5 were changed from 20 to 250 and NH₃ temperature programmed desorption (TPD) was carried out. As the Si/metal ratio was changed from 250 to 20, the selectivities for aromatics were increased from 5.3 % to 52.3 % over [Ga]ZSM-5 and from 10.1% to 25.7% over [Al]ZSM-5. NH₃ TPD of [Ga]ZSM-5 indicated that the sites of medium acidity play an important role in the formation of aromatics. When H₂ and CO were added to the reactant of pentane, the production of methane and ethane increased and that of aromatics decreased.     

丙烷芳构化催化剂活性组分浸渍方法优化

根据现有丙烷芳构化催化剂的特性,考察等体积浸渍、真空等体积浸渍、微波等体积浸渍3种不同浸渍方法对镓改性HZSM-5催化剂性能的影响,并结合多种技术表征,分析改性后催化剂内部性能变化情况。研究发现,浸渍方法对催化剂表面镓的分散度具有明显的影响,其中真空等体积浸渍具有更好的效果,使活性组分Ga分散更均匀,更有效地降低了分子筛的B酸位、增加了L酸位,进而抑制了丙烷的裂解,增强了催化剂的脱氢、芳构化能力,并且延长了催化剂的寿命。在反应温度为525℃,丙烷质量空速（WHSV）为1 h^-1的条件下,取样时间为丙烷通入后1.3 h,丙烷转化率达到93.8%,液相芳烃收率达到57.2%,BTX（苯、甲苯和二甲苯）收率达到48.6%。     

Propylene aromatization on Ga-MFI Zeolites

Propylene aromatization reaction was performed on various MFI type zeolites containing Ga species. The Ga was introduced into the zeolites by substitution (Ga-MFI), ion exchange (GIZ) and physical mixing (GPZ). A com-mercialized zeolite (PQZSM-5) was also used for comparison. The catalysts prepared were characterized by using XRF, XPS, surface area measurement, NH₃-TPD, and H₂-TPR. Through the Ga substitution, the acidity of the modified catalysts was decreased, and dehydrogenation and aromatization reactions occurred more easily. The lattice Ga did not react well with hydrogen contrary to the Ga located at the outside of the lattice. It was also found that Ga-MFI catalysts facilitate alkylation reactions. This paper is dedicated to Professor Wha Young Lee on the occasion of his retirement from Seoul National University