酸处理改性Hβ分子筛催化合成乙基蒽醌

采用微波辐射法,对Hβ分子筛进行酸处理改性,并通过NH₃-TPD、XRD和吡啶－IR对分子筛进行表征,考察改性前后分子筛酸性质和晶相变化,采用改性的Hβ分子筛催化乙苯和苯酐合成乙基蒽醌。结果表明,无机酸改性分子筛时,由于酸性太强,溶解了大量分子筛的铝物种,减小了分子筛固有的酸催化中心数,使分子筛的催化活性大幅度下降,不适合作为Hβ分子筛的改性试剂。有机酸对Hβ分子筛的改性效果较好,以0.1 mol·L^-1马来酸处理后的分子筛催化效果最好,苯酐转化率为51.53%,乙基蒽醌选择性为39.10%,乙基蒽醌收率最高可达20.15%。采用马来酸和Ce(NO₃)·6H₂O复合改性分子筛,乙基蒽醌选择性为54.0%,乙基蒽醌收率最高可达23.5%,选择性比马来酸单独改性时提高约15个百分点,催化效果明显提高。     

改性二氧化硅负载离子液体催化合成2-(4-乙基苯甲酰基)苯甲酸

对负载离子液体催化乙苯与邻苯二甲酸酐酰化反应合成2-(4-乙基苯甲酰基)苯甲酸(BE酸)进行了研究。以AlCl₃溶液和混合酸为改性剂，对二氧化硅载体进行改性，采用浸渍法制备系列负载离子液体，采用FT-IR、BET、SEM和XRD对催化剂进行表征，考察载体改性剂、负载温度和负载量对催化剂性能的影响，并对反应条件进行了优化。结果表明，负载型离子液体在催化合成BE酸的反应中有较高的活性，但目标产物BE酸的选择性较低。经过混合酸对载体改性后，邻苯二甲酸酐的转化率和BE酸的选择性达到100％和91.1％，催化剂综合性能明显提高。催化剂再生后，BE酸的选择性为88.92%。     

氨水改性H-β沸石分子筛在2-乙基蒽醌制备中的催化性能

利用弱碱氨水(NH_3·H_2O)处理H-β分子筛使其具备一定的介孔结构。与Na OH等强碱相比,利用氨水改性H-β分子筛不仅条件温和而且制备过程简洁,无需通过离子交换。对制备的催化剂进行X射线粉末衍射、透射电子显微镜、氮气吸脱附等表征。结果表明,经氨水处理的样品的结晶度有所下降同时产生了介孔结构,所得催化剂在2-(4'-乙基苯甲酰基)苯甲酸(BE酸)脱水合成2-乙基蒽醌(2-EAQ)中表现出比常规H-β沸石更好的催化性能。     

介孔Beta沸石的后处理法制备及其在合成2-乙基蒽醌中的催化性能

用先碱后酸的后处理方法制备了介孔Beta沸石催化剂,采用x射线粉末衍射、扫描电子显微镜、氮气吸脱附方法对催化剂进行了表征。结果表明,尽管碱处理样品的结晶度有一定程度的下降,但其含有丰富的介孔,具有大分子催化反应所需的良好的扩散传质效应。后续的柠檬酸处理除去碱处理操作产生的非骨架铝物种,所得催化剂在2-(4'-乙基苯甲酰基)苯甲酸(BE酸)脱水合成2-乙基蒽醌(2-EAQ)中具有比常规Beta沸石更好的催化性能。     

离子液体催化合成2-(4-乙基苯甲酰基)苯甲酸

研究了离子液体催化合成2-(4-乙基苯甲酰基)苯甲酸。并对离子液体中[Bmim]Cl与三氯化铝的摩尔比、原料配比、反应温度和反应时间等工艺条件进行了考察。较优工艺条件为:n(AlCl3)∶n([Bmim]Cl)=1∶3,n(离子液体)∶n(邻苯二甲酸酐)∶n(乙苯)=1∶1∶1,反应温度为50℃,反应时间为4h,在此条件下,[Bmim]Cl-AlCl3催化邻苯二甲酸酐的转化率可达100%,目标产物2-(4-乙基苯甲酰基)苯甲酸的选择性达97.14%,可避免使用有机溶剂。     

2-乙基蒽醌的合成研究

一、引言2-乙基蒽醌是蒽醌法制备双氧水必不可少的反应载体,又是光聚合敏化剂。2-乙基蒽醌还用于制备感光化合物—二苯基蒽衍生物并且是醇空气氧化成醛或酯的活化剂。国外报导乙基蒽醌合成途径是采用乙苯和苯酐为原料,三氟化硼和氟化氢为催化剂,在不锈钢压热器中用液氮冷却至-40～0℃,在20巴压力下进行缩合反应。减压蒸馏回收催化剂后制得含量为81%的粗2-乙基苯甲酰基苯甲酸,收率为60%。粗     

沸石分子筛催化合成2-甲基蒽醌反应性能的研究

以HZ-1沸石替代传统均相酸催化剂,在液-固多相催化的间歇式反应条件下,通过一步反应催化合成了2-甲基蒽醌。并考察了HZ-1沸石交换次数等制备条件和催化剂用量对甲苯的苯甲酰化反应的影响。在催化剂用量为2.5g,反应温度为250℃时,邻苯二甲酸酐的转化率达到71.4%,2-甲基蒽醌的选择性为89.0%。二次交换沸石的催化性能较好。     

2-(4'-乙基苯甲酰基)苯甲酸的合成工艺研究

以二氧化硅负载的磷钨酸(PTA/Si O2)为催化剂,邻苯二甲酸酐和乙基苯为原料,氯苯为溶剂来合成2-(4'-乙基苯甲酰基)苯甲酸(BEA)。实验使用FT-IR表征对产物进行了定性分析,结果显示产物中含有BEA;使用紫外—分光光度计对产物进行了定量分析,考察了催化剂用量、反应时间、反应温度对BEA收率的影响。实验结果表明在m(催化剂)∶m(邻苯二甲酸酐)=1∶8(质量比),反应温度180℃,反应时间4.0 h的条件下,BEA收率达到54.6%。     

超声浸渍无机盐改性Hβ分子筛催化合成乙基蒽醌

采用超声浸渍法将无机盐Al₂(SO₄)₃、(NH₄)₂SO₄、Ce(NH₄)₂(NO₃)₆和Fe(NO₃)₃负载于Hβ分子筛上,通过NH₃-TPD、XRD和吡啶-IR对分子筛进行表征,考察改性前后分子筛酸性能和晶相的变化。将改性的Hβ分子筛用于催化乙苯和苯酐合成乙基蒽醌。结果表明,不同无机盐超声浸渍改性分子筛的催化效果差别较大,其中,每克分子筛负载0.2 g的Al₂(SO₄)₃的Alβ分子筛催化效果最好,苯酐转化率为45.67%,乙基蒽醌选择性为50.12%。分子筛的酸性能（包括酸量、酸种类和酸强度）对催化性能影响较大。     

N-（4-乙基苯甲酰基）-N’-叔丁基肼的合成

用对乙基苯甲酸和亚硫酰氯反应制得对乙基苯甲酰氯，后者再在缚酸剂和相转移催化剂存在下与盐酸叔丁基肼反应，可得到高收率高纯度的标题化合物。     

Effect of acid treatment of Fe-BEA zeolite on catalytic N<Subscript>2</Subscript>O conversion

The effect of acid treatment on the physical and chemical characteristics of BEA zeolite, as well as the catalytic activity of the Fe-BEA catalyst for N₂O reduction under NH₃-selective catalytic reduction (NH₃-SCR) conditions, was examined. The acid treatment caused dealumination of BEA and enrichment of the silanol groups on vacant T-sites and the Brønsted acid sites. As the acid treatment time increased, the silanol groups and the weak acid sites in BEA also increased. Because the weak acid sites behave as anchoring sites for Fe ions, the catalytic activity also increased as the treatment time increased. However, extended exposure of BEA to acid decreased the catalytic activity of the Fe-BEA catalyst somewhat, and decreased the silanol groups and weak acid sites. The catalytic activity and the amount of weak acid sites were well correlated with the BEA acid treatment time.     

Catalytic oxidation of diesel soot on mixed oxides derived from hydrotalcites

The dehydration of 2-(4′-ethylbenzoyl) benzoic acid (BE acid) for the synthesis of 2-ethylanthraquinone (2-EAQ) has been studied over solid acid catalysts. Among the catalysts tested, a H-Beta zeolite, which was modified by dilute HNO₃ solution, exhibited high catalytic performances. A 96.7% yield of 2-EAQ was achieved in our study in a batch reactor. The influences of various parameters, such as reaction temperature and time, the weight ratio of BE acid to H-Beta zeolite were investigated in detail.     

固体酸表面B酸和L酸与果糖转化制乳酸甲酯产物分布

制备了γ-Al₂O₃、HZSM-5、SnOPO₄、SnZrOPO₄(1:1)、SO₄^2-/ZrO₂5种不同的固体酸催化剂,采用NH₃程序升温脱附、吡啶原位吸附红外对催化剂进行了表征。考察了固体酸催化果糖在甲醇中转化的催化性能,结果表明,果糖的转化率均高于98%,产物分布与固体酸表面L酸、B酸酸量具有显著的相关性,乳酸甲酯的收率随着L酸量的减少而降低,L酸催化剂γ-Al₂O₃催化,主产物只有乳酸甲酯,收率为24.4%。而L酸位和B酸位共存的固体酸,产物中有乳酸甲酯、乙酰丙酸甲酯,并且乙酰丙酸甲酯的收率随着B酸量的增多而升高。最后考察了典型L酸γ-Al₂O₃及B酸L酸共存的固体酸HZSM-5不同反应时间的产物分布,结合气相-质谱联用对产物定性分析,得出了果糖转化过程L酸位催化和B酸位催化的反应路径。     

Ni/ZrO2-SiO2催化剂催化乙酰丙酸加氢合成γ-戊内酯

分别以ZrO₂、SiO₂及ZrO₂-SiO₂复合氧化物为载体,采用等体积浸渍法制备了Ni含量为10%（质量分数）的催化剂,考察了其催化乙酰丙酸液相加氢性能。采用N₂-物理吸附、NH₃-TPD、H₂-TPR、XRD、TEM等表征手段对催化剂进行了表征。研究结果表明,在所制备的催化剂上,乙酰丙酸先经C=O加氢生成4-羟基戊酸,后者快速脱水酯化为γ-戊内酯。Ni/ZrO₂-SiO₂催化剂较Ni/ZrO₂与Ni/SiO₂催化剂具有高的金属分散度和丰富的表面酸性中心,表现出高的C=O加氢活性以及优异的乙酰丙酸加氢合成γ-戊内酯性能。在反应温度为200℃,氢气压力4 MPa的反应条件下,乙酰丙酸的转化率达到100%,γ-戊内酯的选择性大于99.9%。     

Acidity of β zeolite with different Si/Al2 ratio as measured by temperature programmed desorption of ammonia

High quality β zeolite (BEA) with a Si/Al₂ ratio of 30:70 was readily prepared by a dry gel conversion method. Acidity of the thus prepared β zeolite was measured by an improved technique of temperature programmed desorption of ammonia. Concentration of acid site, measured from the desorbed ammonia, was nearly equal to that of aluminum in the zeolite, and the enthalpy change of ammonia desorption, i.e., the strength of acidity, was 124–127 kJ mol⁻¹, and independent of the concentration of acid site. The long tailing desorption of ammonia was distinct at higher temperature, and this was characteristic of BEA. The tail-like desorption spectrum may be correlated with the presence of strong acid site due to the defect or the tetrahedral site with different structural environments; the conclusion was supported by the characterization data using NMR, IR, and test reaction. Thus found solid acidity was compared with that of the commercially available β zeolite; the observed small difference was explained due to the presence of extra-framework Al.     

Zr改性Y分子筛中油型加氢裂化催化剂设计制备

采用等体积浸渍法对Y分子筛进行了Zr修饰改性,系统考察了不同用量Zr对改性Y分子筛的结构、催化剂的理化性质和加氢裂化反应性能的影响规律。通过XRD、NH₃-TPD、H₂-TPR和TEM等方法对改性分子筛和催化剂进行表征分析。结果表明：Zr改性降低了Y分子筛的酸量,随着改性Zr用量的增加,这种变化趋势不断增大。同时,Zr改性有效地削弱了分子筛催化剂中金属活性组分与载体间的作用,提高了W物种在催化剂表面的分散程度。加氢裂化反应结果表明：与Y分子筛催化剂相比,Zr改性Y分子筛催化剂的减压馏分油(VGO)转化率降低,中间馏分油选择性提高约20%,随着改性Zr用量的增加,VGO的转化率不断降低,中间馏分油选择性略有增加。     

Sn改性Hβ分子筛催化顺酐酯化

采用离子交换法对Hβ分子筛进行骨架外Sn改性制得Sn-Beta分子筛,应用于顺丁烯二酸酐与正丁醇的酯化反应,并与Hβ分子筛进行对比。研究结果表明,Hβ分子筛的催化性能优于Sn-Beta分子筛,顺丁烯二酸酐转化率达98.0%,马来酸二丁酯产率达73.9%。采用X射线粉末衍射、N2物理吸附、傅里叶红外光谱、紫外-可见漫反射光谱和NH3程序升温脱附等技术对分子筛的物化性质进行表征,结果表明,Hβ分子筛比表面积大,孔容和孔径较大,酸量较多,有利于酯化反应的进行。     

Deactivation aspect of BEA zeolite in microwave assisted synthesis of 2-cyclohexyl-4-methyl phenol by cyclohexylation of p-cresol

Selective synthesis of 2-cyclohexyl-4-methyl phenol (2-CH-4-MP) by liquid phase alkylation of p-cresol with cyclohexanol and cyclohexene over BEA zeolite has been investigated under microwave as well as conventional heating. Significant acceleration of reaction rate was observed under microwave heating. However, no difference in conversion or selectivity was noticed between the two modes of heating. Various reaction parameters like catalyst amount, mole ratio of reactants, temperature and reaction time showed a significant influence on the distribution of products. With cyclohexanol as alkylating agent, initially formed cyclohexene and O-alkylated product were converted to 2-CH-4-MP with increase in temperature, catalyst amount and reaction time. When cyclohexene is used directly as alkylating agent, C-/O-product ratio also increased with increase in temperature, catalyst amount and reaction time. However, in both the cases, selectivity to 2-CH-4-MP was almost same. Deactivation of BEA zeolite was observed during the reaction possibly due to coking constituents. In an attempt to stabilize the catalytic activity of BEA zeolite, it was dealuminated to different extents by treating with 0.1, 0.2 and 0.5 M solutions of p-toluene sulphonic acid. The catalytic activity and deactivation behaviour of dealuminated samples in the alkylation reaction were investigated.     

复合固体超强酸SO42-/ZrO2-TiO2催化合成三醋酸甘油酯

采用复合固体超强酸SO₄^2-/ZrO₂-TiO₂为催化剂，甘油和冰醋酸为原料，结合醋酸精馏回流工艺，合成了三醋酸甘油酯（TCG）。通过对合成工艺改进，免除了有毒带水剂的使用。使TCG合成更安全，更经济和环保。催化剂制备和TCG合成最佳工艺条件为：硫酸浸渍液浓度（0.5～0.55） mol·L^－1，焙烧温度（550～600） ℃，催化剂用量（占总投料量质量分数）2.5％～3.0%。投料比n（甘油）∶n（醋酸）=1∶ 5.5，反应温度130 ℃，反应时间3.0 h，产品收率达92.6%，催化剂可重复使用6次，易于再生。