SO42-/ZrO2的制备工艺对催化橡胶籽油裂解油酯化的影响

以SO₄^2-/ZrO₂为催化剂对橡胶籽油裂解油进行甲酯化。研究了锆源、焙烧温度及焙烧时间对催化剂活性的影响,分别采用氨气吸附程序升温脱附(NH₃-TPD)和吡啶红外(Py-IR)对固体酸SO₄^2-/ZrO₂的酸性和酸型进行分析。实验结果表明,以ZrOCl₂为锆源,550℃焙烧4 h所得固体酸SO₄^2-/ZrO₂的催化活性最好,性能较稳定。对酯化产物的组成及性能进行了考察,结果表明,酯化产物的各项性能均优于传统工艺制备的生物燃油,且与0^#柴油相近。     

SO42-/ZrO2和SO42-/Al2O3-ZrO2催化剂上的正戊烷反应

研究了添加Al对SO₄^2-/ZrO₂超强酸样品的晶化、比表面、硫含量、超强酸性和正戊烷反应性能的影响,考察了活化温度、反应温度、Al含量和载Pt对催化剂活性和选择性的影响.SO₄^2-/Al₂O₃ZrO₂催化剂的酸强度与SO₄^2-/ZrO₂基本相当,但超强酸位比后者多,未载Pt时正戊烷反应活性和稳定性明显高于后者.负载Pt后,正戊烷异构化选择性和稳定性大大提高,但Pt/SO₄^2-/Al₂O₃ZrO₂催化剂的反应活性与Pt/SO₄^2-/ZrO₂相近,Al的促进作用不明显.     

高酸值生物柴油原料甘油酯化脱酸研究

利用共沉淀-浸渍法制备了Al改性固体酸催化剂SO₄^2-/ZrO₂,考察了催化剂在甘油酯化脱酸制备生物柴油原料反应中的催化活性、重复利用性和再生性能,并对使用前后的催化剂进行了红外光谱分析。研究表明,添加适量Al(1%,以Al₂O₃的质量分数计)不但提高了催化剂的活性,还改善了催化剂的重复利用性和再生性能。添加Al使ZrO₂上SO₄^2-的量增加,SO₄^2-结合强度增强,减少了在酯化脱酸反应过程中SO₄^2-的流失。在SO₄^2-/ZrO₂-Al₂O₃催化剂用量为7％、甘油与酸物质的量比为6:1、反应温度为140 ℃、反应时间为4 h的条件下,酯化率可达91%以上,可将高酸值油脂的酸值从31 mg_KOH/g降低到2.8 mg_KOH/g以下,可满足生物柴油原料的要求。     

Pd含量对SO42-/ZrO2-WO3固体超强酸催化剂其异构化性能的影响

制备了Pd-SO₄^2-/ZrO₂-WO₃型固体超强酸催化剂,并采用XRD、FT-IR、TPR、XPS、BET和TG-DTA等表征手段对催化剂进行了表征。以正戊烷异构化为探针反应,考察了Pd含量对催化剂异构化活性的影响。结果表明,Pd可以明显地降低催化剂的还原温度,提高催化剂中SO₄^2-的分解温度,从而提高了催化剂热稳定性。当Pd质量分数为0.05%时,Pd-SO₄^2-/ZrO₂-WO₃固体超强酸催化剂的催化活性最好。该催化剂在反应温度260℃、反应压力2.0 MPa、质量空速为1.0 h^-1、氢油比为4.0时,异戊烷收率和液收率为40.1%和93.9%。     

稀土改性对SO42-/ZrO2固体酸催化剂结构与催化性能的影响

采用共沉淀法和浸渍法在不同条件下制备了稀土-SO₄^2-/ZrO₂系列固体酸催化剂。使用废油脂与甲醇的酯交换反应评价了催化剂活性,并通过X射线衍射、红外光谱、比表面积测定表征方法考察了催化剂结构和性能的关系。结果表明,La摩尔掺杂量4%、焙烧温度600℃时制得的SO₄^2-/ZrO₂-La₂O₃催化剂活性最高,此时脂肪酸甲酯的产率为64.68%,且具有较好的重复使用性。稀土的引入使活性四方相ZrO₂更加稳定,600℃焙烧使催化剂既具有较多活性四方相ZrO₂,又具有较大比表面积,从而提高了催化剂活性。催化剂中形成了固体超强酸结构,且改性后酸强度增大,催化剂活性中心数目增加。     

SO42-/MxOy型固体超强酸催化剂研究(Ⅰ)

合成了一种新的SO₄^2-/M_xO_y型固体超强酸-SO₄^2-/ZrO₂-Fe₂O₅,研究了它对正戊烷反应的活性与选择性;制备并测定了SO₄^2-/TiO₂固体超强酸对正戊烷的异构化活性与裂解活性及其某些物性;重复合成了文献报导的SO₄^2-/ZrO₂固体超强酸并测定了它对正戊烷异构化的催化性能,表明所采用的测定方法与所得结果可与文献值相比较。     

SO42-/ZrO2-Al2O3催化剂表面酸性质对正丁烷异构化反应性能的影响研究

采用“沉淀-浸渍”法制备一系列不同硫酸负载量的SO₄^2-/ZrO₂-Al₂O₃催化剂,利用N₂吸附-脱附、Py-FTIR、XRD等手段对催化剂进行表征。在常压、200 ℃、H₂：C₄=2：3和质量空速为3 h^-1的反应条件下,在固定床微型反应评价装置上考察了硫酸负载量对SO₄^2-/ZrO₂-Al₂O₃催化正丁烷异构化反应性能的影响。Py-FTIR结果表明,硫酸化处理为催化剂表面提供了丰富的Brønsted酸性位,其中,强Brønsted酸性位在正丁烷异构化反应中起重要作用,因此,硫酸化处理可显著提高正丁烷异构化活性,而Lewis酸性位与之没有直接关系。     

实验参数对磁性AgI-BiOI/CoFe2 O4光催化剂湿法脱除Hg0的影响

采用水热-共沉淀法制备了一种新型的磁性AgI-BiOI/CoFe₂O₄复合材料光催化剂,考察了荧光灯辐照下光催化剂脱除模拟烟气中单质汞（Hg⁰）的性能,研究了实验参数对脱汞性能的影响及反应产物。结果表明,AgI-BiOI/CoFe₂O₄光催化剂的热稳定性较差,当煅烧温度超过400 ℃时该光催化剂的化学成分会发生变化;随着催化剂用量、反应溶液pH值、反应溶液温度和烟气中O₂浓度的增加,脱汞效率先增加后不变或下降;反应溶液中存在的CO₃^2-和SO₄^2-对脱汞效率有一定的抑制作用;当通入SO₂时,脱汞效率急剧下降;而NO对脱汞效率的抑制作用相对较小。反应产物分析表明,SO₂、NO和Hg⁰的最终氧化产物分别是SO₄^2-、NO₃^-和Hg²⁺     

改性固体超强酸S2O82-/ZrO2-CoO用于FCC汽油氧化脱硫的研究

以硝酸锆、硝酸铜和硝酸钴为金属源,过硫酸铵作为浸渍液,采用共沉淀浸渍法合成出固体超强酸催化剂S₂O₈^2-/ZrO₂、S₂O₈^2-/ZrO₂-CuO和S₂O₈^2-/ZrO₂-CoO,通过XRD、FT-IR、NH₃-TPD、BET对催化剂进行表征。结果表明,Co（钴）改性催化剂S₂O₈^2-/ZrO₂-CoO在三种催化剂中超强酸位最多。将其作为催化剂,过氧化氢作为氧化剂用于FCC汽油氧化脱硫反应,研究不同反应温度、催化剂用量、反应时间、氧化剂用量对FCC汽油脱硫效果的影响。结果表明,FCC汽油氧化脱硫的最佳条件为：反应温度70 ℃,反应1.5 h,FCC汽油加入量与氧化剂体积比7.5：1,催化剂用量0.02 g/mL。反应产物利用N,N-二甲基甲酰胺进行萃取分离,萃取剂/汽油体积比为1：1时,FCC汽油脱硫率最高可达85.34%,回收率为94.45%,并且催化剂表现出较为稳定的催化活性。     

固体酸S2O82-/Nb2O5/La3+的制备、表征及催化合成乙酸正丁酯

以Nb₂O₅为载体,浸渍法研制固体酸（S₂O₈^2-/Nb₂O₅/La⁺）催化剂,经SEM、XRD和EDS表征,考察了固体酸的焙烧温度、陈化时间及S₂O₈^2-浓度等因素对该催化剂催化活性的影响。结果表明：在(NH₄)₂S₂O₈浓度为1 mol/L、浸渍时间18 h、w(La³⁺)=3%（基于Nb₂O₅的质量）、焙烧温度为500 ℃时,制备出最高催化效果的催化剂。接着考察了其催化合成乙酸正丁酯的催化活性,通过正交实验确定了反应的最佳条件：n(正丁醇)/n(冰醋酸）=2.0/1.0、催化剂用量w（S₂O₈^2-/Nb₂O₅/La³⁺）=2.9%（基于反应物质量）、反应温度为125 ℃,反应时间为3.0 h,酯化率为95.70%。催化剂循环利用3次后仍有90.1%的酯化率。      

复合固体超强酸催化剂SO2-4-WO3-ZrO2的结构研究

Solid superacid catalyst SO4(2-)-WO3-ZrO2 was characterized by means of XRD,DTA-TG, and surface area measurement techniques. The dependence of the surface area, SO42- content of the catalyst on calcination temperature was measured. It was found that there is a synergy to a certain degree between SO42- and WO3 with respect to the delay of ZrO2 crystallization, the stabilization of the tetragonal ZrO2 and the enlargement of the surface area of the catalyst. The addition of WO3 is beneficial to the stabilization of SO42- and remarkably increases the stability of SO42- at high temperature.     

大孔SO42-/ZrO2-SiO2复合固体酸制备及催化性能

利用浸渍水解法在大孔SiO2载体上组装固体酸制备出大孔径SO42-/ZrO2-SiO2复合固体酸催化剂。用扫描电镜、红外光谱仪和粉末X射线衍射仪等对其进行表征,结果表明:大孔SiO2载体的毛细管效应促使ZrO2以纳米薄层方式均匀地沉积在SiO2薄层表面,并抑制了ZrO2晶体的生长和晶相的转变,载体的大孔全连通的结构赋予该复合材料高的通透性(孔径在1~2μm)、两面活性点和大的比表面积(约156 m2.g-1)。Hammett指示剂法测得经550℃焙烧后产物的酸强度H0值小于-13.75,属于固体超强酸。以乙酸正丁酯的合成为探针反应考察硫酸浸渍液浓度、焙烧温度等制备条件对其催化活性的影响,结果表明,该SO42-/ZrO2-SiO2固体酸具有较好的催化活性,当焙烧温度为550℃和硫酸浸渍液浓度为1.5 mol.L-1时,超强酸对酯化反应的催化酯化率达到97%。     

用晶型超细粒子ZrO2制备SO4^2^—／ZrO2超强酸催化剂的研究

用超临界流体干燥法制备了超细粒子晶型ZrO_2,并用稀H_2SO_4溶液对其进行处理,制得了对甲醇转化反应具有高活性的SO_4~(2-)/ZrO_2超强酸催化剂.首次发现,晶型金属氧化物ZrO_2,当它是超细粒子(粒径<0.1μm)时,同样可以用H_2SO_4溶液浸渍的方法制得SO_4~(2-)/ZrO_2固体超强酸.这一事实同时还说明,超细粒子与非超细粒子不仅在某些物理性质上有较大区别,而且在化学性质上也有差别.     

Catalysis of SO42--ZrO2/TiO2 nanometer solid superacid

Superacid catalyst SO42--ZrO2/TiO2 was applied in esterification of Acetic Acid and Butanol. The particle size of ZrO2 in the catalyst was about 12.5 nm. In catalyst preparation conditions, the effect factor order on catalytic activity is H2SO4 concentration ＞ calcination temperature ＞ ZrO2 supported content. The optimum preparation condition is as follows: ZrO2 content 3.5g/g; calcination temperature 600℃, and H2SO4 concentration 0.5mol/L. The catalytic activity is 96.5 vol%.SO42-/MxOy solid superacid is a kind of green catalyst, whose application perspective is bright. In this paper, SO42--ZrO2/TiO2 solid superacid was prepared with nanometer compound carrying method. The acidic strength of catalysts was measured with the following Hammett indicators, 2,4-dinitrofluorobenzene (H0=-14.52) and p-nitrochlorobenzene (H0=-12.70). Catalytic activity was evaluated with esterification reaction of Acetic Acid and Butanol. Reaction temperature was at 105℃, and reaction time was only 1h. The conversion rate of Acetic Acid was analyzed by a gas chromatograph (GC-14C SHIMADZU in Japan)The experimental results showed that H2SO4 concentration had more influences on catalytic activity than other two factors, calcination temperature and ZrO2 supported content. Since sulfur absorbed on the surface of metal oxides is necessary to the acidity of SO42-/MxOy solid superacid,H2SO4 concentration in impregnation solution is needed enough high. But, it can't be too much high,otherwise, Zirconium sulfate formed on the catalyst surface will be harmful influences on catalytic activity. In researched cover, 0.5mol/L H2SO4 concentration is the most suitable, and the catalyst prepared with this concentration has very strong acidity.The optimum preparation condition is as follows: ZrO2 content 3.5g/g; calcination temperature 600℃, and H2SO4 concentration 0.5mol/L. In the catalyst prepared with above conditions, the acidic strength (H0) of the catalyst is smaller than ＜-14.52, and catalytic activity is 96.5 vol%. When it was re-used in esterification reaction, catalytic activity decreased gradually with re-used times increasing(seen in Table 1). But after catalyst is used repeatedly up to five times, catalytic activity (84.3 vol %)is still higher than that of H2SO4 catalyst.The X-ray diffraction patterns showed that ZrO2 supported in TiO2 belonged tetragonal zirconia phases. Through the calculation of Scherrer formula, the particle size of ZrO2 in the catalyst is about 12.5 nm. After SO42- promoted nanometer ZrO2/TiO2 compound carrier, the diffraction peaks of tetragonal zircoma become broader and the strength weaker. It shows that adding SO4 ions restrains the crystallization of ZrO2, diminishes the size of particles. This might be why SO42--ZrO2/TiO2 has high catalytic activity and stability in acidic catalysis reaction.     

Autothermal reforming of methane over Ni catalysts supported over ZrO2-CeO2-Al2O3

Ni catalysts supported on Al2O3, ZrO2-Al2O3, CeO2-Al2O3 and ZrO2-CeO2-Al2O3 were prepared by coprecipitation method, and their catalytic performances for autothermal reforming of methane to hydrogen were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. The relationship between the structures and catalytic activities of the catalysts was discussed. The results showed that the catalytic activity and stability of the Ni/ZrO2-CeO2-Al2O3 catalyst was better than those of other catalysts with the highest CH4 conversion, H2/CO and H2/COx ratio at 750 ℃. The catalyst showed a little deactivation along the reaction time during its 72 h on stream with the mean deactivation rate of 0.08%/h. The catalytic performance of the Ni/ZrO2-CeO2-Al2O3 catalyst was also affected by reaction temperature, no2 ： nCH4 molar ratio and nH2O ： nCH4 molar ratio. TPR, XRD and XPS measurements indicated that the formation of ZrO2-CeO2 solid solution could improve the dispersion of NiO, and inhibit the formation of NiAl2O3, and thus significantly promoted the catalytic activity of the Ni/ZrO2-CeO2-Al2O3 catalyst.     

Effects of Zr/Ti molar ratio in SO42-/ZrO2-TiO2 calcined at different temperatures on its surface properties and glucose reactivity in near-critical methanol

Effects of Zr/Ti molar ratio in SO42-/ZrO2-TiO2 solid acid catalyst calcined at different temperatures on its surface properties and catalytic activity were thoroughly investigated in this paper. The physicochemical characteristics of prepared samples were determined by N2 adsorptiondesorption, XRD, NH3-TPD and XPS techniques, respectively. It was found that the crystallization temperature of the samples increased after the combination of ZrO2 and TiO2; and phase transformations from the anatase to the rutile of TiO2 species and the tetragonal to the monoclinic of ZrO2 species were effectively suppressed at higher temperature. The sample with a Zr/Ti molar ratio of 3/1 calcined at 450℃ showed the highest surface area and the most acid sites among all the tested samples. The acid site densities of samples were relatively closed to each other if they were calcined at the same temperature, however, decreased with the calcination temperature. The result indicates that the sulfur content in samples is a crucial factor to control the acid site density. Calcining the sample at 650℃ and higher temperatures resulted in a significant desorption of sulfate ion on the samples. The synthesized samples were evaluated as a potential catalyst for glucose conversion under the near-critical methanol conditions (200℃/4 MPa). The results suggested that the relatively weaker acid sites of the catalyst were more favorable for the accumulation of methyl glucosides, while the moderate acid sites were responsible for the formation of methyl levulinate. The catalytic activity for methyl levulinate production almost increases linearly with the catalyst acid site density. The catalyst deactivation is due to the loss of sulfate ion and the two catalysts with Zr/Ti molar ratios of 3/1 and 1/3 could effectively alleviate the deactivation caused by sulfate solution in the reaction medium and can be reused after calcination with the reuse rate of over 90% in terms of the methyl levulinate selectivity.     

稀土固体超强酸SO42-/ZrO2-SnO2-Nd2O3的制备及催化合成乙酸松油酯

采用分沉淀-共浸渍法制备了新型稀土固体超强酸SO42-/ZrO2-SnO2-Nd2O3,利用IR、TG-DTA、XRD表征了催化剂的物化性质,并用于催化乙酸酐和松油醇合成乙酸松油酯,显示了良好的反应活性和重复使用性,对反应条件进行了优化,结果表明最佳反应条件为：松油醇和乙酸酐的摩尔比1∶1.5,反应温度50 ℃,反应时间5 h,催化剂用量占松油醇质量的2 %,在此反应条件下松油醇的转化率为93%左右,产物中乙酸松油酯的含量为87%。催化剂失活主要原因是有机物在表面吸附,通过无水乙醇洗涤,干燥,即可再生。     

SO_4~(2-)/ZrO_2催化剂上正丁烷异构化反应

考察了活化温度、反应温度、空速、Ｈ２／Ｃ４比和载Ｐｔ对ＳＯ２－４／ＺｒＯ２催化剂的正丁烷异构化反应活性和稳定性的影响．较高的Ｈ２／Ｃ４比可提高ＳＯ２－４／ＺｒＯ２催化剂的稳定性和稳态活性．催化剂负载Ｐｔ后，可降低反应原料中的Ｈ２／Ｃ４比．积炭是造成反应初始阶段催化剂迅速失活的主要原因，经烧炭再生以后这部分失活可以完全恢复     

掺杂助剂Ce和Zr的Ni/Al2O3催化剂的X光电子能谱分析

以Na2CO3为沉淀剂,在pH 9.0的沉淀条件下,采用并流沉淀法制备了Ni/Al2O3、Ni/CeO2-Al2O3、Ni/ZrO2-Al2O3和Ni/ZrO2-CeO2-Al2O34种催化剂,催化剂中Ni负载量(质量分数)为10%。采用XPS表征手段及常压固定床反应器对催化剂进行活性评价,考察了助剂Ce和Zr及二者的协同作用对Ni基催化剂表面物种结合能的影响以及对甲烷自热重整制氢反应性能的影响。结果表明,助剂Ce和Zr的添加及二者的协同作用对Ni基催化剂表面各物种的结合能均有一定的影响,结合评价结果可知,Ce和Zr二者的协同作用对Ni基催化剂的催化性能提高最大。     

在SO42-/ZrO2 上苯与丙烯的烷基化反应

Super acidic catalyst SO42-/ZrO2 was prepared and characterized by XRD,IR,and Py-IR. Selectively catalytic gas phase flow reactions of benzene and propene over the catalyst were carried out in a made-to-measure high pressure flow reactor with a thermometer and a condenser. The benzene and propene were kept in pressure tanks at 8 : 1 ratio with N2 gas at 4. 0 MPa. The reactants were pumped into the quantifier where the pressure was maintained by N2 gas at 8. 0 MPa. They were then pumped into the reaction reactor using catalytic synthesis of isopropyl benzene. The collected liquid phase products were analyzed using GC-MS. Product analyses were carried out on SE-54. The effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalysts has been tested. The result shows that the SO42-/ZrO2 can be used as a catalyst for the title reaction,and shows higher conversion（99.2%）for the propene and higher selectivity（93.3%）for the isopropyl benzene when the catalyst is preparated in some condition.