钴基催化剂的制备及性能评价

以γ-Al_2O_3为载体,采用等体积浸渍法制备F-T合成钴基催化剂,在F-T合成小型固定床反应装置评价催化剂。考察并优化了钴源、焙烧温度、钴负载量、反应温度和原料气空速等工艺条件对催化荆活性和F-T合成产物收率的影响,测试了Co/γ-Al_2O_3催化剂的稳定性。结果表明,最佳制备条件:以硝酸钴为钴源,焙烧温度400℃,钴负载质量分数10%。在温度230℃、压力2 MPa、原料气组成n(H_2)∶n(CO)=2和反应空速1 800 h~(-1)的条件下,进行60 h运转实验,CO转化率可达69.1%,C_5~+烃收率高达89.6%。     

采用HTLcs前驱体制备的丙酮一步法制MIBK催化剂

采用共沉淀法制备Cu Mg A1三元类水滑石,进而煅烧得到CuO MgO Al2O3催化剂用于丙酮加氢一步合成甲基异丁基酮(MIBK)反应。研究了催化剂活性组分配比及反应条件对转化率和选择性的影响,经筛选得到催化剂体系的最佳组成为:n(Cu)∶n(Mg)∶n(Al)=4∶16∶10,适宜的反应条件为:温度240℃,n(H2)∶n(丙酮)=2.5,液空速为4.8mL/h·g,在该条件下丙酮转化率达73.88%,MIBK选择性达55.23%。     

盐酸普萘洛尔的合成

以3-(1-萘氧基)-1,2-环氧丙烷和异丙胺为原料,合成了中间体普萘洛尔,经氯化氢酸化得到盐酸普萘洛尔。考察了催化剂种类、反应物配比、反应温度、反应时间对中间体普萘洛尔收率的影响。优化工艺条件为：n(3-(1-萘氧基)-1,2-环氧丙烷)∶n（异丙胺）=1.0∶1.2,催化剂为水,加入量为2 mL,反应温度为50℃,反应时间为4 h。优化条件下盐酸普萘洛尔收率为83.2%。     

4-氯苯异氰酸酯绿色合成工艺研究

用"绿色化学品"碳酸二甲酯(DMC)代替光气与4-氯苯胺反应合成4-氯苯异氰酸酯.研究了反应物质量比、温度、时间、催化剂用量对合成目标物产率的影响,建立了获得目标产物的最佳工艺条件.实验结果表明,ZnO催化剂用量为0.06 g,物料比n(DMC)∶n(4-氯苯胺)为8∶1,反应温度80℃,反应时间6 h,收率为62.1...     

甲乙酮胺化加氢合成仲丁胺催化工艺研究

采用固定床反应器,以甲乙酮(MEK)、氨和氢气为原料,在改性镍催化剂作用下,气相催化胺化加氢合成仲丁胺。研究了反应温度、液时空速、氨酮摩尔比、氢酮摩尔比和反应压力等因素对合成反应的影响。在反应温度120~150℃,液时空速0.1~0.5h~(-1),氨酮摩尔比3~5和氢酮摩尔比8~12的条件下,甲乙酮转化率在91%以上,仲丁胺选择性在87.16%以上。     

负载型Ni-B/γ-Al_2O_3非晶态合金催化剂的结构及苯加氢性能

采用化学还原法制备了镍质量分数为7%、镍硼摩尔比为1∶3.4的负载型Ni-B/γ-Al2O3非晶态合金催化剂,并对催化剂进行了表征。结果表明NiB以非晶态的形式负载在γ-Al2O3载体上;Ni-B/γ-Al2O3非晶态合金催化剂的晶化温度应在240~440℃;最佳活化温度在200~260℃。在反应压力0.5 MPa、氢苯比4、空速1.0 h-1的条件下,反应温度高于160℃时,苯加氢制环己烷产率均为100%。     

油酸缩水甘油酯及其改性胺的制备研究

采用羧酸-环氧氯丙烷酯化、闭环二步法合成油酸缩水甘油酯,其最佳合成工艺条件为:w(催化剂)=2%(相对于油酸质量而言),酯化反应温度90℃,n(油酸)∶n(环氧氯丙烷)=1.0∶3.5,环化反应温度70~75℃,Na OH浓度23%,n(油酸)∶n(Na OH)=1.0∶2.0,环化反应时间4 h。将制得的缩水甘油酯与异佛尔酮二胺进行胺化反应得到改性胺固化剂,其与环氧树脂618固化产物的冲击强度为18.6 k J/m~2,体现出优良的增韧效果。     

6-苯基-[1,2,4]三唑[4,3a]吡啶-3-胺的合成及工艺优化

以5-溴-2-氟吡啶为原料,经取代、成环、偶联反应,合成了医药中间体6-苯基-[1,2,4]三唑[4,3-a]吡啶-3-胺(Ⅳ),利用1HNMR、13CNMR和高分辨质谱对其结构进行了表征。对中间体6-溴-[1,2,4]三唑[4,3-a]吡啶-3-胺(Ⅲ)的合成方法和反应机理进行了探讨,考察了反应时间、反应温度、反应物配比、溶剂配比、催化剂用量等对目标产物收率的影响,结果表明:化合物Ⅲ的最佳合成工艺条件为:反应温度40℃,反应时间15 min;化合物Ⅳ的最佳合成工艺条件为:溶剂配比V(水)∶V(1,4-二氧六环)=1.0∶2.0,n(Ⅲ)∶n(苯硼酸)=1.0∶1.2,n(Ⅲ)∶n[Pd(pph3)2Cl2]=1.0∶0.1,反应温度80℃。经三步反应得到化合物Ⅳ的总收率为60%。     

合成异丙胺工艺技术研究进展

异丙胺是应用广泛的低级脂肪醇胺,主要用于医药和农药等领域。随着一些下游产品的开发,对异丙胺的需求量也随之增长。合成异丙胺主要有异丙醇催化加氢胺化法和丙酮加氢催化胺化法。采用何种方法优势更大,主要取决于原料价格。镍基催化剂价格低廉,活性较高,是今后催化剂研究重点。丙酮法工艺成熟,但反应中副产物较多,生产成本较高;异丙醇反应副产物较少且易控制。     

Ni/γ-Al_2O_3催化剂上甲烷水蒸气重整制合成气

采用固定床装置,考察了负载型Ni系列催化剂及反应条件对Ni/γ-Al2O3催化剂的甲烷水蒸气重整反应的影响,并利用XRD和TPR技术对催化剂样品进行表征。结果表明,在空速1 800 h-1,n(H2O)∶n(CH4)∶n(N2)=2.86∶1∶3.28,反应温度700℃的条件下,催化剂Ni含量在9%时反应性能最佳,可得到94.3%的CH4转化率和64.9%的CO选择性。     

镍/氧化铝加氢催化剂的制备及性能研究

羟基新戊醛（HPA）的加氢多采用贵金属和铜系催化剂,为了更好地降低催化剂生产成本和操作成本,分别对比了共沉淀法和浸渍法制备的镍/氧化铝催化剂,并以HPA为原料,在固定床装置上考察了系列催化剂加氢合成新戊二醇（NPG）的催化性能。采用X射线衍射（XRD）、氮气物理吸附（BET）、一氧化碳脉冲吸附等方法进行表征,结果表明,浸渍法制备的20%镍/氧化铝催化剂,比表面积较大,金属分散性好,且催化剂中的镍物种易被还原,其反应性能良好。在相对较温和的反应条件下,即反应温度为103 ℃、反应压力为3 MPa、液时空速为1 h^-1、氢醛物质的量比为10时,HPA转化率为100%,NPG选择性为99.3%。在1 000 h的长周期评价过程中,该催化剂保持了较好的活性,具有更好的工业化前景。     

Mg、La助剂在镍基甲烷化催化剂中的协同作用

采用浸渍法制备Ni/Al2O3、La-Ni/Al2O3、Mg-Ni/Al2O3和Mg-La-Ni/Al2O3催化剂,讨论Mg和Ni两种助剂的协同作用,通过N2低温吸附、H2-TPR、XRD和SEM等表征方法对4种催化剂进行分析。结果表明,La助剂有利于削弱NiO与载体间的相互作用,降低催化剂中γ-NiO含量,但形成活性较低的α-NiO。Mg能够抑制催化剂中NiAl2O4尖晶石的形成,但Mg的添加会导致催化剂孔道堵塞,使NiO在催化剂表面团聚。Mg能够与NiO形成固溶体,在Mg的协同作用下,可抑制La-Ni/Al2O3催化剂中α-NiO的生成。La能够促进NiO分散,克服Mg-Ni/Al2O3催化剂孔道堵塞的缺陷。活性评价实验结果表明,添加不同助剂的催化剂在不同温度区域的活性不同,La-Ni/Al2O3催化剂低温活性较好,Mg-Ni/Al2O3催化剂高温活性较好,而在Mg和La两种助剂的协同作用下,Mg-La-Ni/Al2O3催化剂活性最高。     

Ethanol steam reforming over Ni/La–Al2O3 catalysts: Influence of lanthanum loading

Hydrogen production from ethanol reforming over nickel catalysts supported on lanthanum loaded Al₂O₃ substrates was studied. Activity results revealed the enhancement in the reforming stability of the Ni catalysts with the increase in the lanthanum loading on Al₂O₃ substrates. Catalytic behavior of Ni/La–Al₂O₃ catalysts in the ethanol steam reforming was found to be the contribution of the activity of the La–Al₂O₃ supports for the ethanol dehydration reaction and the activity of the nickel metallic phase that catalyzes both dehydrogenation and CC bond rupture. Physicochemical characterization of catalysts revealed that acidity, nickel dispersion and nickel-support interaction depend on the La-loading on Al₂O₃. The better reforming stability of catalysts with the increase in La content was explained in terms of the ability of nickel surface and/or La–Ni interactions to prevent the formation of carbon filaments.     

Ni-Mn/Al2O3催化剂在浆态床中CO甲烷化催化性能

采用共浸渍法制备了Ni-Mn/Al₂O₃催化剂,考察了助剂Mn的含量对催化剂结构及浆态床CO甲烷化性能的影响。采用XRD、H₂-TPR、BET、TEM、H₂-化学吸附等表征对催化剂进行了测试分析,结果表明,Mn助剂的引入能够促进Ni物种在载体表面的分散,减弱Ni物种与载体的相互作用,降低催化剂的还原温度,提高催化剂的比表面积,减小活性金属Ni的晶粒尺寸。随着Mn含量的增加,Ni-Mn/Al₂O₃催化剂的甲烷化性能先升后降,其中以Mn含量为4%（质量分数）时的催化甲烷化性能最佳,添加过量的Mn导致活性组分Ni被部分覆盖,催化甲烷化性能下降。通过对16Ni4Mn/Al₂O₃催化剂样品的浆态床反应温度及反应压力的研究发现,当反应温度为280℃、反应压力为1.5 MPa时,催化剂样品16Ni4Mn/Al₂O₃的CO转化率及CH₄选择性分别达到96.2%和88.8%。     

Development of Ni catalysts for tar removal by steam gasification of biomass

Catalytic performance of Ni/CeO₂/Al₂O₃ catalysts prepared by a co-impregnation and a sequential impregnation method in steam gasification of real biomass (cedar wood) was investigated. Especially, Ni/CeO₂/Al₂O₃ catalysts prepared by the co-impregnation method exhibited higher performance than Ni/Al₂O₃ and Ni/CeO₂/Al₂O₃ prepared by the sequential impregnation method, and the catalysts gave lower yields of coke and tar, and higher yields of gaseous products. The Ni/CeO₂/Al₂O₃ catalysts were characterized by thermogravimetric analysis, temperature-programmed reduction with H₂, transmission electron microscopy and extended X-ray absorption fine structure, and the results suggested that the interaction between Ni and CeO₂ became stronger by the co-impregnation method than that by sequential method. Judging from both results of catalytic performance and catalyst characterization, it is found that the intimate interaction between Ni and CeO₂ can play very important role on the steam gasification of biomass.     

Ni/Al_2O_3催化剂的CO_2-TPD表征

Ni/Al_2O_3催化剂是甲烷二氧化碳重整反应制取合成气研究最多、最具应用潜力的一种催化剂。通过对催化剂进行CO_2-TPD研究,考察还原态Ni/Al_2O_3催化剂的CO_2脱附特性。结果表明,浸渍法制备的Ni/Al_2O_3催化剂CO_2脱附曲线呈现双峰,分别在(60~65)℃和(350~380)℃出现高低温两个活性位;高温CO_2吸附量为3.0 cm~3·g~(-1),低温CO_2吸附量为24.0 cm~3·g~(-1)。催化剂的CO_2吸附量与其Ni含量无关。考察选用不同载体的CO_2脱附行为,发现以Al_2O_3为载体的催化剂CO_2吸附量是MgO和SiO_2为载体催化剂的2~4倍,以TiO_2为载体的催化剂几乎不吸附CO_2。     

添加Ni对Cu基催化剂乙炔选择性加氢性能的影响

采用等体积浸渍法制备了Cu/Al_2O_3及Cu-Ni/Al_2O_3催化剂,将其应用于乙炔选择性加氢反应。结果表明,与Cu/Al_2O_3催化剂相比,Cu-Ni/Al_2O_3催化剂的加氢活性及乙烯选择性(当反应出口尾气中乙炔物质的量分数减少到0.003%时)明显提高。通过对Cu与Ni的浸渍顺序考察发现,先浸渍Ni制得的Cu-Ni/Al_2O_3催化剂活性有所下降,但乙烯选择性提高;通过对Ni含量的考察发现,当Ni质量分数为2%时,催化剂性能最佳。     

Effect of the addition of transition metals to Pt/Ba/Al2O3 catalyst on the NOx storage-reduction catalysis under oxidizing conditions in the presence of SO2

The NO_x storage-reduction catalysis under oxidizing conditions in the presence of SO₂ has been investigated on Pt/Ba/Fe/Al₂O₃, Pt/Ba/Co/Al₂O₃, Pt/Ba/Ni/Al₂O₃, and Pt/Ba/Cu/Al₂O₃ catalysts compared with Pt/Ba/Al₂O₃, Pt/Fe/Al₂O₃, Pt/Co/Al₂O₃, Pt/Ni/Al₂O₃, Pt/Cu/Al₂O₃ and Pt/Al₂O₃ catalysts. The NO_x purification activity of Pt/Ba/Fe/Al₂O₃ catalyst was the highest of all the catalysts investigated in this paper after an aging treatment. That of the aged Pt/Ba/Co/Al₂O₃ and Pt/Ba/Ni/Al₂O₃ catalysts was essentially the same as that of the aged Pt/Ba/Al₂O₃ catalyst, while that of the aged Pt/Ba/Cu/Al₂O₃ and Pt/Cu/Al₂O₃ catalysts was substantially lower than the others.

The Fe-compound on the aged Pt/Ba/Fe/Al₂O₃ catalyst has played a role in decreasing the sulfur content on the catalyst after exposure to simulated reducing gas compared with the Pt/Ba/Al₂O₃ catalyst without the Fe-compound. XRD and EDX show that the Fe-compound inhibits the growth in the size of BaSO₄ particles formed on the Pt/Ba/Fe/Al₂O₃ catalyst under oxidizing conditions in the presence of SO₂ and promotes the decomposition of BaSO₄ and desorption of the sulfur compound under reducing conditions.     

焙烧温度对Al2O3载体的性质及其负载的煤制合成气制代用天然气镍基催化剂性能的影响

以拟薄水铝石为前驱体,经不同温度焙烧制得Al₂O₃载体,等体积浸渍法制备Ni/Al₂O₃催化剂,采用X射线衍射、N₂-物理吸附、扫描电镜、程序升温还原等对载体及催化剂进行表征,考察载体焙烧温度对Al₂O₃载体性质及其负载的镍基催化剂催化性能的影响。结果表明,随着焙烧温度的升高,Al₂O₃载体的比表面积减小,平均孔径增大,结晶度升高,晶粒度增大,晶型逐步转变为γ-Al₂O₃［(500~800) ℃］、δ-Al₂O₃［ (900~1 100) ℃］和α-Al₂O₃［(1 250) ℃］。合成气制甲烷催化剂活性变化趋势为:Ni/γ-Al₂O₃>Ni/δ-Al₂O₃>Ni/α-Al₂O₃,其中,800 ℃焙烧的γ-Al₂O₃负载的Ni基催化剂因稳定的晶型结构以及与NiO之间适当的相互作用而表现出最佳的催化活性及稳定性。     

Role of CeO2 in Ni/CeO2–Al2O3 catalysts for carbon dioxide reforming of methane

Ni catalysts supported on γ-Al₂O₃, CeO₂ and CeO₂–Al₂O₃ systems were tested for catalytic CO₂ reforming of methane into synthesis gas. Ni/CeO₂–Al₂O₃ catalysts showed much better catalytic performance than either CeO₂- or γ-Al₂O₃-supported Ni catalysts. CeO₂ as a support for Ni catalysts produced a strong metal–support interaction (SMSI), which reduced the catalytic activity and carbon deposition. However, CeO₂ had positive effect on catalytic activity, stability, and carbon suppression when used as a promoter in Ni/γ-Al₂O₃ catalysts for this reaction. A weight loading of 1–5 wt% CeO₂ was found to be the optimum. Ni catalysts with CeO₂ promoters reduced the chemical interaction between nickel and support, resulting in an increase in reducibility and stronger dispersion of nickel. The stability and less coking on CeO₂-promoted catalysts are attributed to the oxidative properties of CeO₂.