络合剂对LaSrFeCoO6催化剂制备及催化性能影响

通过溶胶凝胶法,分别采用柠檬酸、酒石酸、葡萄糖、蔗糖、EDTA作为络合剂制备LaSrFeCoO₆催化剂,以催化甲烷燃烧为目标反应,考察催化剂的活性。通过比表面积测定(BET)、X射线衍射分析(XRD)、氢还原(H₂-TPR)、扫描电镜(SEM)及热分析(TG-DSC)等技术对催化剂进行性能表征。考察不同络合剂对LaSrFeCO₆催化剂结构和性能影响。通过实验结果可以得到：经过800℃高温焙烧后,催化剂具有完整的钙钛矿晶型。不同络合剂对催化剂的结构和性能有较大影响;柠檬酸作为络合剂时,所制备LaSrFeCO₆催化剂具有较好的催化活性,T_10%(起燃温度)为425℃,T_90%(完全转化温度)为600℃。     

甲烷氧化偶联钙钛矿型纳米催化剂的制备及性能测定

采用溶胶-凝胶法制备了SrTiO3及其镁掺杂的钙钛矿型复合氧化物超细微粒催化剂,应用TEM、XRD等手段,研究所得超细微粒催化剂的粒子大小、组成结构与OCM反应催化性能。结果表明:高温、粒子细化、B位掺杂对OCM反应CH4的转化率、C2选择性都有提高。750℃时,SrTi0.9Me0.1O3对OCM反应的甲烷转化率为28.9％,C2选择性为60.0％。     

太阳光下La~(3+)掺杂TiO_2纳米粒子光催化降解亚甲基蓝的动力学研究

利用酸催化的快速溶胶-凝胶法(sol-gel)制备了一系列不同La3+掺杂量(x=0.01%～3%)的TiO2复合光催化剂;在太阳光条件下,以亚甲基蓝溶液的光催化降解为模型反应,研究了染料的光催化降解动力学行为,考察了催化剂投加量和La3+掺杂量对复合光催化剂活性的影响.结果表明,亚甲基蓝的光催化降解反应遵循Langmuir-Hinshelwood动力学模型,表观反应速率常数随着反应体系中催化剂用量和La3+掺杂量的不同而不同,均存在一个最佳值.在本实验条件下,当催化剂投加量为1.5g/L,La3+掺杂量为0.5%时,测得表观反应速率常数为2.1.×10-2mg(L·min)-1,反应120min后亚甲基蓝的降解率可达91.55%.     

La元素掺杂增强BaZr0.15Ti0.85O3陶瓷的介电性能实验研究

通过固相反应法制备了La离子掺杂的BaZr0.15 Ti0.35 O3(BZT)陶瓷.研究了La离子掺杂对BZT陶瓷的晶体结构、微观形貌和介电性能的影响.X射线衍射表明,所制备的BZT陶瓷均为钙钛矿赝立方相,La离子添加后衍射峰向高角度偏移;拉曼光谱测试表明,[A1(TO3)]拉曼峰加强,且没有杂相生成,La离子掺杂后...     

助剂对负载型镍催化剂催化性能的影响

应用XRD、TPR和催化活性评价手段 ,考察了助剂对CH4 与CO2 重整制合成气的负载型Ni催化剂的最大分散量和其催化性能的影响 .实验结果表明 ,在反应温度为 750℃和空速为2 50 0h- 1下 ,NiO载量为 14%NiO/γ -Al2 O3催化剂具有最佳的反应性能 ,NiO在γ -Al2 O3表面上最大分散量为 0 .2 38gNiO/gγ -Al2 O3(相当于 0 .112gNiO/10 0m2 γ -Al2 O3) ,其最大分散量随MgO、La2 O3助剂的添加不同程度地增大 ;助剂能影响负载型Ni催化剂的催化性能 ,MgO、La2 O3的添加对改善Ni催化剂的重整活性和抗积炭能力有明显效果 .La2 O3助剂的突出作用表现在维持Ni为低价还原态和促进CO2 转化等方面 .     

La3+掺杂纳米TiO2制备及其性能的研究

采用溶胶-凝胶法制备了系列La3+掺杂的纳米TiO2,用X射线衍射(XRD)、扫描电镜(SEM)、X-射线能谱仪(EDS)等测试方法对催化剂进行表征,并以甲基橙溶液为降解目标,测定其紫外光光催化活性.结果表明:La3+的掺杂能有效抑制TiO2纳米颗粒的增长,提高晶相转变温度;稀土La3+的掺杂能有效提高TiO2纳米粉体的光催化活性,最佳初始掺杂物质的量比为0.02%.     

甲烷部分氧化Ni基催化剂的研究

考察了不同Ni担栽量的Ni/α-Al2O3催化剂对甲烷部分氧化的催化性能的影响和助剂Ce对Ni基催化剂性能的调变作用.采用沉淀法以NH3·H2O、Al(NO3)3·9H2O和Ni(NO3)3·6H2O为原料合成Ni/α-Al2O3凝胶,经过高温煅烧制备纳米级催化剂Ni/α-Al2O3粉末.通过固定床反应器进行催化剂的活性评价,并对其进行XRD和TPR分析.结果表明:8%Ni(质量分数)的Ni/α-Al2O3催化剂催化活性最佳,同时添加稀土Ce有助于提高催化剂的活性、选择性和稳定性.     

PVP-Ru/Al2O3催化丙酸甲酯加氢制备丙醇反应研究

本文采用五种不同方法制备了PVP稳定的Ru/Al2O3催化剂,考察了其在丙酸甲酯加氢制备丙醇反应中的催化性能.结果表明,采用金属前体、稳定剂和载体浸渍过夜,然后在磁力搅拌下用NaBH4水溶液还原制备的催化剂催化效果最好.而将金属前体还原后再负载制备的催化剂性能最差.另外,还考察了催化剂加入量、B/Ru及PVP/Ru摩尔比也对催化剂活性和选择性的影响,最佳摩尔比为：PVP/Ru=3：1及B/Ru=10：1.     

氯离子对铂铼双金属催化剂性能的影响

考察了氯离子对[Pt3（CO）6[NEt4]2与Re2（CO）10分浸制备的催化剂性能的影响。发现在催化剂制备过程中加入氛离子，催化性能大大改善。初步分析了氯离子影响催化剂性能的原因。     

稀土掺杂TiO2光催化剂的制备及其光催化活性的研究

采用溶胶-凝胶法和浸渍法制备稀土掺杂TiO2光催化剂RE/TiO2（RE=Pr、Nd、Gd、Er）,利用XRD、BET、DRS、SPS等手段进行表征,研究了稀土掺杂对TiO2的晶相结构、比表面积、吸光性能的影响,考察了RE/TiO2催化剂降解C2H4的气-固相光催化氧化反应性能.结果表明：掺杂适量的稀土离子可以抑制锐钛矿晶型向金红石晶型转变,细化晶粒,增加比表面积,提高光催化活性.     

纳米催化剂研究进展

纳米材料具有独特的晶体结构及表面特性，其催化活性和选择性大大高于传统催化剂，目前已经被国内外作为第4代催化剂进行研究和开发．介绍了纳米材料的催化特性，综述了纳米金属粒子催化剂、纳米金属氧化物催化剂、纳米半导体粒子、纳米固载杂多酸催化剂、纳米(复合)固体超酸催化剂、磁性纳米固体酸催化剂、碳纳米管及分子筛等的应用进展．指出了纳米催化剂的优势及目前存在的问题．     

Preparation and Water—Gas Shift Catalytic Activities of the Perovs—kite Type Complex Oxide La1—xCexFeO3

Thewater gasshiftreaction (WGSR)isanimpor tantstepinmanyindustrialprocesses,includingammoni aandhydrogenproduction .Itisusuallyassistedbysev eralcatalysts ,oneofwhichisiron basedshiftcatalystwithatypicalcompositionof 74 .2 %Fe2 O3,10 .0 %Cr2 O3,0 .2 %MgO ,0 .5 %K2 Oandbalancevolatiles[1] .Obviously ,chromiaasthemainadditivecanbefoundinalmostallofiron basedhightemperaturewater gasshiftcatalysts.ThehexavalentchromiuminCrO3,thepre cursorofchromiainFe Crseriescatalysts ,isakindofveryharmfuls…     

Modification of acidity in HZSM-5 zeolite for methane-methanol co-reaction

A co-reaction of methane with methanol over zeolite catalysts has emerged as a new approach to the long-standing challenge of methane transformation. However, the effect of catalyst acid properties on the co-reaction has been rarely studied. In this study, a series of HZSM-5 zeolites with comparable diffusion abilities and various acidities were synthesized directly through steaming with 100% water vapor at 693 K. The co-reaction of methane and methanol was subsequently evaluated. Br?nsted acidity at 0.262 mmol/g was detected to reach the maximum methane conversion of 5.42% at 673 K, which was also the odd point in the relationship between acid concentration and C4 hydrogen transfer index. Moreover, the influence of methanol feed was investigated over parent and steamed ZSM-5 catalyst, with results showing that excessive acid sites or methanol molecules reduce methane conversion. It is proposed that acid sites adsorbed with methanol molecules construct the methane activation sites. Hence, a proper design of zeolite acidity should be achieved to obtain higher methane conversion in the co-reaction process.     

Dual bed catalyst system for oxidative dehydrogenation of mixed-butenes: a synergistic mechanism

Oxidative dehydrogenation (ODH) of mono and mixed-butenes to 1,3-butadiene (BD) was conducted using individual and dual bed catalyst systems, consisting of ZnFe₂O₄, Co₉Fe₃Bi₁Mo₁₂O₅₁ or both. The dual bed catalyst system gave improved catalytic performance. A mechanism based on synergy between the catalysts is proposed to explain the improved overall butene conversion. The proportion of the reactants differed between the catalyst beds in the dual bed system, making better use of the catalytic activity of the second bed. The existence of all butene isomers inhibited isomerization, leading to a higher proportion of ODH reactions and thus improved the conversion of butene and the yield of BD. The packing sequences and the volume ratio of the catalysts in the bed were optimized. The results indicated that the sequence with ZnFe₂O₄ on top and a catalyst packing ratio of between 4:6 and 6:4 led to better activity.     

制备方法对镍催化剂重整活性影响研究

利用XRD,TPR和活性评价等手段,研究了NiO/γ-Al2O3催化剂的制备方法对CH4与CO2转化制合成气催化活性的影响.在本实验条件下,采用浸渍法和焙烧温度为400℃制备的NiO/γAl2O3(ω=0.113)催化剂,在反应温度为750℃和空速为2500h-1下,对CH4和CO2重整反应会显示良好的催化活性.本文还对催化剂抗积炭性能作初步讨论.     

Attrition resistant catalyst for dimethyl ether synthesis in fluidized-bed reactor

Fluidized-bed reactor is a candidate for dimethyl ether （DME） synthesis from syngas because of its excellent heat removal capability. In order to improve the attrition resistance of catalyst, an amount of silica sol as binder was added to the catalyst composed of methanol synthesis component CuO/ZnO/Al2O3 and methanol dehydration component HZSM-5, which was prepared by coprecipitation and shaped by spray drying to get spherical particles. The effect of silica sol on the catalytic activity was investigated in a fixed-bed flow microreactor. Based on the experiment results, silica sol in the range of 0-20wt% had small effect on the catalytic activity. Generally, the CO conversion and DME yield decreased with the increase in concentration of silica sol, while the attrition resistance of catalysts increased with increasing silica sol, indicating that it was feasible to improve the attrition resistance without greatly sacrificing the activity of catalyst. In addition, the characterizations of catalysts were carried out using Brunauer-Emmett-Teller （BET）, X-ray powder diffraction （XRD） and temperature programmed reduction （TPR）.     

环已酮酸催化合成环已烯环已酮的研究

章研究了环已酮酸催化合成环已烯环已酮过程中，不同种类酸催化剂的作用规律和反应机理。结果表明，强质子酸催化反应的速度较快，催化反应活性亦高；但后处理需经中和、洗涤、干燥等繁锁工序，存在污染环境和腐蚀设备等弊端；详细考察硫酸盐、氯化物盐类等Lewis酸催化剂对反应的催化作用，并比较了催化剂用量、反应时间的影响，发现铁盐的催化性能较好，综合单程产率高。     

Hydrogenation of ortho-nitrochlorobenzene on activated carbon supported platinum catalysts

INTRODUCTION 2,2′-dichlorohydrazobenzene (DHB) is a com-mercially important intermediate, and is convention-ally manufactured by zinc reduction of or-tho-nitrochlorobenzene (Xu, 1996). The major dis-advantage of this process is the generation of largeamounts of sludge in reduction. A single step catalytichydrogenation of ortho-nitrochlorobenzene to DHBusing supported noble metal catalyst in the presenceof aqueous sodium hydroxide medium becomes moreimportant, because it is enviro…     

甲烷氧化偶联催化剂的制备及表征

本文报道了一系列甲烷氧化偶联催化剂的制备过程及其催化性能,筛选出一个催化性能优良,又具有赣南特色的甲烷氧化偶联催化剂,其组成是Mn_2O_3—Na_3WO_4/SiO_2,代号W—34,并用XRD,BET,UV—DRS,EPR,LRS等方法对该催化剂进行了表征。结果表明,在最佳反应条件下,在W—34催化剂上甲烷转化率为36.8％,C_2烃收率达到22.9％。在该催化剂中,W是以Na_2WO_4形式存在,Mn则以Mn_2O_3形式存在,而SiO_2已由无定型构型转变成。一方石英构型。     

不同比表积的Pt负载型催化剂上甲醛催化氧化

为研究铂负载型催化剂时甲醛催化氧化反应的活性,采用溶胶一凝胶法制备了不同载体的铂负载型催化剂,并对催化剂进行XRD、Raman等表征,考察所制催化剂对甲醛催化氧化反应性能。结果表明：载体的性质在反应中起到重要作用,惰性载体无法促进氧的活化,其催化活性较低;对比不同比表面积的Pt／CeO2催化剂,发现比表面积为38mVg的催化剂的催化氧化性能最佳,这与催化剂的氧缺位浓度较高及较强的金属一载体间相互作用有关。