不同载体对镍基催化剂的XPS影响

La掺杂的BaTiO3粉体与未掺杂BaTiO3粉体颗粒大小相仿,前者更为分散。通过XPS试验发现,Ni(2p)的结合能在Ni/B中比在Ni/A中为小,说明Ni/B中的Ni具有更大的电子密度;同样,La、Ce掺杂的镍基BaTiO3催化剂表明稀土元素的掺入能使镍基BaTiO3催化剂表面的镍电子密度增大。Ni/A表面的Ni含量少得多,表面分布较散。BaTiO3和La掺杂BaTiO3的XPS能谱基本相同。     

载体粒度对钯炭催化剂催化活性的影响

利用钯炭催化剂的苯甲酸加氢反应,考察了活性炭载体粒度(<44μm、44~74μm、74~150μm、>150μm对钯炭催化剂催化活性的影响。采用粒度分析法、BET和SEM对其进行表征,并利用加氢反应釜对其催化剂活性进行评价。结果表明:载体粒度>74μm,金属钯负载不均匀,导致催化剂活性下降;载体粒度<44μm,催化剂不易过滤,洗涤过程活性组分容易脱附,导致催化剂活性降低;载体粒度为44~74μm时,催化剂活性最高。     

Y2O3对CuO-ZnO-ZrO2催化剂结构及性能的影响

考察了Y2O3对CuO-ZnO-ZrO2催化剂性能的影响,以甲醇水蒸汽重整为探针反应,并利用XRD、TPR、BET、H2-TPD、CO-TPD和IR等手段对催化剂的结构及性能进行了表征.结果表明,Y2O3的加入提高了催化剂中CuO的分散度、H2吸附量、Cu+的含量及Cu+/Cu0x比,加强了CuO和ZnO之间的相互作用,抑制了Cu+的深度还原,使CuO-ZnO-ZrO2催化剂的甲醇水蒸汽重整制氢反应的活性增大.     

ZrO2-Al2O3复合载体的制备方法对Pd基催化剂加氢脱硫性能的影响

采用连续流动微反装置考察了ZrO2-Al2O3复合载体制备方法对Pd基催化荆加氢脱硫性能的影响,并采用XRD,TPR,H2-TPD.NH3-TPD和H2吸附等技术对催化剂进行了表征.结果表明,复合载体的制备方法对Pd基催化剂加氢脱硫性能有较大的影响,与浸渍法相比,溶胶一凝胶法制备的复合载体增强了活性组分与载体的相互作用,有利于Pd分散度的增大和催化剂酸量的增加,从而有利于Pd基催化剂活性的提高.     

失效载体催化剂回收铂族金属工艺和技术

介绍国内外失效载体催化剂回收铂族金属的3种工艺技术：火法、湿法和火-湿法联合工艺，并作简要评论，     

CeO_2基三效催化剂中金属-载体强相互作用的研究进展

金属-载体强相互作用(SMSI)的发生机理及其对催化活性的影响是目前CeO2基三效催化剂研究的热点。介绍了金属-载体强相互作用产生的基本条件及其基本特征,综述了贵金属与CeO2基复合氧化物间SMSI的可能机制及相关研究进展,提出了金属-载体强相互作用可能的研究方向。     

催化剂载体FeCrAlY材料表面γ-Al2O3活性层的制备

本文介绍了用溶胶—凝胶法制备机动车尾气净化催化剂金属载体 Fe Cr Al Y材料表面γ- Al2 O3 活性层的工艺 ,根据热冲击循环中涂层重量变化讨论了在涂覆溶胶中加入无机类添加剂 ST及涂覆次数对涂层结合力的影响 ,用扫描电子显微镜 (SEM)观察了涂层的表面形貌并分析了涂层脱落情况。     

活性炭载体的超声波处理对Pt／C催化剂活性的影响分析

通过对活性炭载体进行不同条件的超声波处理获得了具有不同表面化学性质的载体，使用比表面积（BET）、酸碱滴定等技术手段对载体的物理化学性质进行了表征。将经过超声波处理的活性炭载体制备成Pt／C催化剂，并将催化剂直接用于催化反应，考察了活性炭载体的不同超声波处理条件对Pt／C催化剂性能的影响。实验发现，活性炭载体经过超声波处理后，表面灰分含量、pH值和中孔孔容有较大的变化；使用经过60min超声波处理后中孔孔容较大的活性炭作为载体制备的Pt／C催化剂，在催化加氢反应性能测试中显示了最高的催化活性。在此基础上，就活性炭载体的超声波处理对Pt／C催化剂活性的影响进行了讨论。     

铈和其它助剂对Pd/m-ZnO催化剂甲醇水蒸气重整制氢性能的影响

以三嵌段高聚物F-127为模板剂采用水热法分别合成了介孔ZnO-MOx(m-ZnO-MOx,M=Ce、Mg和Zr)复合氧化物,研究了铈和其它助剂对Pd/m-ZnO催化剂甲醇水蒸气重整制氢反应性能的影响,并运用XRD、H2-TPR和BET等手段对载体及催化剂进行了表征.与Pd/m-ZnO-MgO 和Pd/m-ZnO-ZrO2催化剂相比,Pd/m-ZnO-CeO2催化剂具有较高的甲醇水蒸气重整制氢活性,m-ZnO-CeO2复合载体较大的比表面积、较小Pd粒子以及Pd与m-ZnO-CeO2较强的相互作用有利于Pd基催化剂制氢活性的提高.     

Effect of RE-Doped and RE Quantity of Ni-Based Catalysts on CH4/CO2 Reforming Reaction

RE-doped Ni-based catalysts were prepared by sol-gel method.These catalysts were applied to the reaction of CO2 reforming CH4 to syngas.The studies reveal that RE-doped ( RE = La, Ce, Sm, Yb) Ni-based catalysts show higher catalytic activity than undoped Ni-based catalyst, and with the increasing of RE-doped quantity, the catalytic activity of catalysts exhibits regular changes.When RE-doped quantity is 0.2% ( molar ratio), the catalysts show the best catalytic activity.     

Study on Coke Formation and Stability of Nickel-Based Catalysts in CO2 Reforming of CH4

CO2 reforming of CH4 over nickel-based catalysts was investigated by using a fixed-bed reactor. Catalytic activity and amount of carbon deposition effects by nickel loading content, rare earth promoter and promoter contents were evaluated. It is found that nickel loading as well as reaction temperature can influence the activity and carbon deposition amounts, and with the addition of rare earth promoter, it can greatly improve the catalytic activity and exert a strong effect on the anticoking performance of the catalysts. The 5.0% (mass fraction)Ni-0.75% La BaTiO3 catalyst shows great resistance to coke formation and higher thermal stability as well as the catalytic activity.     

不同稀土及不同含量的助催化剂对重整反应的影响

考察了不同含量的稀土助剂L a对催化剂比表面积和催化活性的影响,其中以L a含量为1.5%(质量分数)时最佳。催化剂经过973K反应后得到的产物中,H2的量明显大于CO的量,≥1023K时H2/CO的值接近1,这是由于不同温度下催化剂对CH4和CO2活化的程度不同。添加不同稀土助剂催化剂的反应活性与其比表面积有正向关系,比表面积大则活性相对较高,反之则低,其中以L a和Ho为最佳。     

CeO2-Co3O4 Catalysts for CO Oxidation

CeO2-Co3O4 catalysts for low-temperature CO oxidation were prepared by a co-precipitation method. In combination with the characterization methods of N2 adsorption/desorption, XRD, temperature-programmed reduction （TPR）, and FT-IR, the influence of the cerium content on the catalytic performance of CeO2-Co3O4 was investigated. The results indicate that the prepared CeO2-Co3O4 catalysts exhibit a better activity than that of pure CeO2 or pure Co3O4. The catalyst with the Ce/Co atomic ratio 1 ： 16 exhibits the best activity, which converts 77% of CO at room temperature and completely oxidizes CO at 45 ℃.     

Effects of Cerium Oxide on Ni／Al2O3 Catalysts for Decomposition of CH4 and C2H4

Characteristics of carbon deposition of CH4 and C2H4 decomposition over supported Ni and Ni-Ce catalysts were studied by using a pulse reaction as well as BET, TPR, XPS and hydrogen chemisorption techniques. It is found that there is a metal-semiconductor interaction (MScI) in the Ni-Ce catalyst, and the effect of MScI on the carbon deposition of CH4 decomposition is opposite to that of C2H4. A novel model of carbon deposition of CH4 or C2H4 decomposition was proposed.     

Promotional effects of samarium on Co3O4 spinel for CO and CH4 oxidation

A series of Co3O4 spinel catalysts modified by Sm were prepared by co-precipitation method and tested for CH4 and CO oxidation.The addition of a small amount of Sm into Co3O4 led to an improvement in the catalytic activity for both reactions.Co0.98Sm0.02 and Co0.95Sm0.05,the two samples with Co/Sm molar ratio of 0.98/0.02 and 0.95/0.05 in sequence,showed the similar and the highest activity for CH4 oxidation,with CH4 complete conversion at 450 oC.In contrast,Co0.90Sm0.10 was the most active sample for CO oxidation,with CO complete conversion at 120 oC.The catalysts were characterized by techniques of N2 adsortion-desorption with Brunauer-Emmett-Teller technique(N2-BET),X-ray powder diffraction(XRD),thermal gravity analysis-differential scanning calorimetry(TGA-DSC),H2 temperature programmed reduction(H2-TPR) and X-ray photoelectron spectroscopy analysis(XPS).Compared with pure Co3O4,for Co1–x Smx catalysts with 0.02≤x≤0.10,the addition of a small amount of Sm resulted in the formation of spinel Co3O4 and amorphous SmCoO3,hence increasing the number of Co3+ and the active surface oxygen species,which was responsible for the improvement of the activity.Co0.95Sm0.05 catalyst showed not only high thermal stability and activity but also good reaction durability in the presence of 5% water vapor for CH4 oxidation.     

气基竖炉工况焦炉煤气甲烷改质行为试验

 利用焦炉煤气+气基竖炉生产优质海绵铁,可延伸焦化行业产业链,同时可促进中国废钢/海绵铁—电炉短流程发展,改变钢铁行业能源、产品结构。针对典型焦炉煤气,通过基础性试验研究了在气基竖炉工况下,温度、H2O和CO2配比,高温海绵铁载体对焦炉煤气中甲烷改质行为的影响。研究结果表明,提高温度有利于焦炉煤气中甲烷的改质反应,1000℃时改质后有效还原气体体积分数最高可达80%;热态海绵铁对焦炉煤气改质有催化促进作用,可提高CO2参与改质反应比例至84.9%、H2O参与反应比例至100%;CO2配入体积分数2%～6%、H2O配入体积分数4%～10%为促进甲烷改质反应的适宜范围。     

Study on Carbon Nanotubes Prepared from Catalytic Decomposition of CH4 over Lanthanum Containing Ni-Base Catalysts

A series of lanthanum containing Ni-base catalysts were prepared by citric acid complex method.Carbon nanotubes (CNT) were synthesized bY catalytic decomposing CH4 over these catalysts and characterized by XRD, TEM and TGA.It is found that the addition of lanthanum can not increase the yield of carbon nanotube, but can make the diameter of carbon nanotube thinner and even.The more the lanthanum addsr, the thinner the diameter of CNTs becomes.With the CNTs prepared on Ni-Mg catalyst, the CNTs prepared on Ni-La-Mg catalyst has better crystallinity and thermal stability.     

Reduction and carburization of iron-ore in a fluidized bed by CO,H2 and CH4

The reduction and carburization of fine iron-ore (100 - 200 μm, Fe₂O₃ mass content of 98%) by gas mixtures containing CO, H₂ and CH₄ was investigated in a fluidized bed at temperatures of 400 up to 700°C. In this temperature range carbon is formed from CO via the Boudouard reaction as well as by the decomposition of methane. Yet, both reactions only occur in the presence of metallic iron and therefore only at reduction degrees of the DRI (direct-reduced iron) of more than 33%. As a contribution to the development of a DRI process without a costly hot briquetting, the influence of the C- and O-content of the DRI on its tendency to reoxidize was also investigated by means of the ignition point method. It was found that reoxidation (at 20°C) of a totally reduced DRI can be suppressed by carbon mass contents of more than 7%. With decreasing reduction degrees, this value decreases, until for reduction degrees of less than 80% no carbon is needed to suppress reoxidation. With regard to the final reduction of the DRI in the electric arc furnace, the molar C to O ratio should be one. The maximal reduction degree is then about 86% to stabilize carbon rich DRI (C mass content of 4%) against reoxidation.     

Nd3+-TiO2催化剂的制备及对合成甲醇的影响

用等体积浸渍法和溶胶凝胶法制备了两种Nd3+-TiO2催化剂,并用X射线衍射、透射电镜和紫外可见吸收光谱等技术表征了催化剂的形貌、结构及吸光性能,对比研究了两种Nd3+-TiO2催化剂对二氧化碳和水合成甲醇反应体系的催化活性,探索了最佳的Nd掺杂量、体系反应温度、二氧化碳压力、光照时间。试验表明,尽管两种合成方法所得的催化剂最佳的Nd掺杂量相差不大,但用溶胶凝胶法制备的Nd3+-TiO2催化剂平均粒径更小,分布均匀,对目的反应的催化效果更好。