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 共查询到19条相似文献,搜索用时 78 毫秒
1.
李爽  彭艳兵 《催化学报》1999,20(4):415-418
以含硼杂原子分子筛HBZSM-5为载体,考察了其担载MoO3后催化甲烷无氧芳构化反应的性能,并结合XRD,IR,TG和SEM等手段对催化剂进行了表征。实验结果表明,MoO3/HBZSM-5催化剂具有较高的甲烷芳构化活性,但稳定性较差,随着引入分子筛骨架中硼量的增大,甲烷的极值转化率增高;随着反应温度的升高,MoO3/HBZSM-5催化剂的甲烷芳构化活性升高。从产物分布的变化来看,硼的引入对于催化剂  相似文献   

2.
二氧化碳甲烷化催化剂研究Ⅳ.海泡石担载催化剂的性能   总被引:1,自引:0,他引:1  
二氧化碳甲烷化催化剂研究Ⅳ.海泡石担载催化剂的性能*江琦林强黄仲涛(华南理工大学化学工程系,广州510641)邓国才陈荣悌(南开大学化学系,天津300071)关键词二氧化碳,甲烷化,金属催化剂,担载型催化剂,海泡石在二氧化碳甲烷化反应中,最为常见的催...  相似文献   

3.
负载型Ni—B非晶态合金催化剂的表征及催化性能   总被引:2,自引:0,他引:2  
马爱增 《催化学报》1999,20(6):603-607
采用ICP,XRD,DSC,SEM和TEM等技术对负载型Ni-B非晶态合金催化剂进行了表征,研究了这类催化剂对乙烯中微量乙炔的选择加氢性能。结果表明,在负载型非晶态合金催化剂中,Ni-B超细微粒的形式分散在载体上,但在不同载体上的分散度不同。通过载体的引入,提高了非晶态合金的热稳定性,阻止了超细Ni-B的聚集。负载型非晶态合金催化剂对乙烯中微量乙炔的选择加氢表现出优良的催化性能。  相似文献   

4.
研究了以沥青活性炭为载体的Ni-W催化剂制备参数与其加氢脱硫(HDS)、加氢脱氮(HDN)和加氢脱芳(HDA)活性的关系,并利用广延X射线吸收精细结构.(EXAF)、透射电镜(TEM)研究了金属原子的近程配位情况及金属的分散状况.发现金属原子比、催化剂焙烧气氛和温度等对催化剂活性有较大影响.浸渍液PH值与载体PHIEP的相对关系对催化活性的影响与浸渍方式有关.表征结果表明,“类WS2”结构的完整性影响了催化剂活性,焙烧气氛温度影响了金属硫化物的分散度.  相似文献   

5.
Ni-P/SiO2催化剂晶化过程及其加氢活性研究   总被引:3,自引:0,他引:3  
采用化学还原法制备了负载型Ni-P/SiO2非晶态合金催化剂,应用ICP、BET、氢氧滴定法、XRD、SEM、XPS研究了上述催化剂在高温晶化过程中的表面结构、表面形貌和表面电子态的变化。测定了Ni-P/SiO2非晶态合金晶化前后对其液相苯甲醛加氢反应催化活性和选择性。并讨论了非晶态合金催化剂晶化过程中结构变化对催化性能的影响。  相似文献   

6.
采用BET、XRD、SEM和XPS等方法对Ba/MgO催化剂进行了分析,并且对该催化剂对甲烷氧化偶联反应的性能进行了测试。结果表明,制备方法对Ba/MgO催化剂的催化性能有很大影响。采用淤浆法制备的Ba/MgO催化剂具有合适的比表面积和表面氧物种分布,因此对甲烷转化显示出良好的催化活性。而采用机械混合或浸渍等方法制备的催化剂由于表面不均匀以及表面烧结等原因其活性较差。  相似文献   

7.
镧助剂对Fe/ZrO2催化剂结构及F-T反应性能的影响   总被引:10,自引:1,他引:10  
陈开东  颜其洁 《催化学报》1997,18(3):199-202
用XRD,Mossbauer谱,TPR,CO-TPD和CO加氢反应性能测试等手段研究了镧助剂对Fe/ZrO2催化剂结构及F-T合成催化剂性能的影响。结果表明,不同的制备方法明显影响催化剂的结构及反应的性能,镧助剂以La2O3形式存在时,催化剂上甲烷选择降低,烯烃选择性提高;镧助剂以LaFeO3形式存在时,催化剂的催化活性大大提高,但同时甲烷选择性上升,烯烃选择性下降。  相似文献   

8.
用惰性气体蒸发法和电弧等离子体法制备了纳米铜粒子,用物理干法将其担载到载体上,并用于催化CO氧化反应.用TEM,XRD,SEM对纳米粒子和催化剂进行了表征.结果表明,载体、氧化气氛及制备工艺均影响催化剂的活性,稀土元素铈的存在能提高铜的催化活性,纳米铜在催化过程中将转变为氧化物.  相似文献   

9.
用惰性气体蒸发法和电弧等离子体法制备了纳米铜粒子,用物理干法将其担载到载体上,并用于催化CO氧化反应。用TEM,XRD,SEM对纳米粒子和催化剂进行了表征。结果表明,载体,氧化气氛及制备工艺均影响催化剂的活性,稀土元素铈的存在能提高铜的催化活性,纳米铜在催化过程中将转变为氧化物。  相似文献   

10.
新型Ni基加氢催化剂的研究(英文)   总被引:1,自引:0,他引:1  
以酸处理海泡石为载体,用浸渍法制备了一系列含不同助剂的Ni基海泡石催化剂。以二氧化碳甲烷化、苯加氢、抗毒及抗热实验对助剂的影响进行了考查。结果表明,助剂尤其是钐的加入能显著地提高Ni基催化剂的加氢活性、热稳定性及抗毒能力。  相似文献   

11.
采用浸渍法制备了Ni/sepiolite及Ni-Sm/sepiolite催化剂并测定了催化剂的CO甲烷化活性,采用抗热实验,XPS及CS2中毒等手段研究了钐对Ni/sepiolite催化剂的影响,结果表明,加入Sm2O3提高了Ni/sepiolite催化剂的甲烷化活性,催化剂热稳定性及抗毒能力,降低了镍原子的电子结合能。  相似文献   

12.
The effect of samarium on Ni/sepiolite catalyst was investigated by benzene hydrogenation, methanation of carbon dioxide, CO chemisorption, XPS and CS2 poisoning, respectively. The result indicates that a proper amount and impregnation order of samarium in the preparation of Ni-Sm/sepiolite catalyst are very efficient to improve the catalytic activity and anti-sulfur ability. At the same time, the mechanism of samarium improving hydrogenation activity of Ni/sepiolite is presented.  相似文献   

13.
助剂对Ni/海泡石催化剂加氢性能的影响   总被引:10,自引:0,他引:10  
以海泡石为载体,Ni为活性组,用浸渍法制备了一系列含不同助剂的Ni基海泡石催化剂,以CO2甲烷化及苯加氢为探针反应,研究了催化剂的活性及抗硫性能,用H2-TPD、XPS、活性表面积及活化能的测定等于段,对催化剂进行表征,并从热力学上探讨CO2甲烷化的适宜温度。实验结果表明,海泡石或助剂的加入,能使镍晶粒变小,增加活性镍的表面积以及使镍原子的电子云密度升高,从而提高了催化剂的活性和使用寿命。能使镍晶  相似文献   

14.
In this work, CO2 methanation has been investigated over Ru-based catalysts. The effects of promoters on the activity, selectivity and reduction properties of the Ru/sepiolite catalyst were analyzed by kinetic and thermodynamic methods. The catalysts were characterized by means of TPD. and the results revealed that the addition of Mo. Mn or Co improved tile properties of the Ru/sepiolite catalyst.The effects of promoters could affect the change of enthalpy,entropy and chemical potential.  相似文献   

15.
The effects of Mo,Mn and Zr transitional metals on the catalytic performance of Ru/sepiolite for CO2 methanation were investigated. The results indicated that addition of the transitional metals affected the activity of the Ru/sepiolite remarkably,and the activities of the catalysts were closely associated with the electronic state of the ruthenium surface,The addition of Mo increased the active surface area,the Ru dispersity,the number of active sites,and the resistance to poisoning.According to the Transition State Theory,when Mo is added into the Ru/sepiolite catalyst,the decrease in surface energy is at a cost of an increment in steric hindrance.When T≤674K,the energy factor was dominating,and resulted in a decreasing in the ratio of S(CH4)/(CO).Otherwise,the steric factor dominated the reaction course.  相似文献   

16.
二氧化碳甲烷化机理的研究(英文)   总被引:1,自引:0,他引:1  
首先对二氧化碳甲烷化的二种机理进行了回顾,并对这二种机理存在的可能性进了探讨。结果表明,二氧化碳甲烷化经过一氧化碳加氢的可能性不大,而经过甲酸根中间体加氢的可能性极大。同时对在一氧化碳与二氧化碳共存时,一氧化碳对二氧化碳甲烷化的影响进行了动力学分析。  相似文献   

17.
Series of carbon nanotube supported Ru-based catalysts were prepared by impregnation method and applied successfully for complete removal of CO by CO selective methanation from H2-rich gas stream conducted in a fixed-bed quartz tubular reactor at ambient pressure.It was found that the metal promoter,reduction temperature and metal loading affected the catalytic properties significantly.The most excellent performance was presented by 30 wt% Ru-Zr/CNTs catalyst reduced at 350℃.Since it decreased CO concentration to below 10ppm from 12000ppm by CO selective methanation at the temperature range of 180-240℃,and kept CO selectivity higher than 85% at the temperature below 200℃.Characterization using XRD,TEM,H2-TPR and XPS suggests that Zr modification of Ru/CNTs results in the weakening of the interaction between Ru and CNTs,a higher Ru dispersion and the oxidization of surface Ru.Amorphous and high dispersed Ru particles with small size were obtained for 30 wt% Ru-Zr/CNTs catalyst reduced at 350℃,leading to excellent catalytic performance in CO selective methanation.  相似文献   

18.
将键级守恒-Morse势方法应用于合金体系, 作了部分修正。通过与Ni(100), Cu(100)比较, 研究了NiCu(100)上合成气甲烷化反应活性。表明, 因Cu的加入, NiCu上甲烷化反应活性较Ni上显著降低, 并通过CO在Ni上解离形成的积碳现象给予了解释。此外, 还考察了甲烷化反应的速控步骤, 及因解离物种可能在表面上的沉积使表面有所改性, 从而影响CO甲烷化表面反应的活性。  相似文献   

19.
In this work, a facile hydrothermal route was used to prepare nano‐sized MoS2 catalyst. The effect of citric acid during the MoS2 preparation process on the catalytic activity of sulfur‐resistant CO methanation was investigated. It was found that citric acid played an adverse role on the catalytic activity of MoS2 toward sulfur‐resistant CO methanation. However, CO methanation performance turned out to be better when NH2OH?HCl as a reductant was removed during the catalyst preparation process. The X‐ray diffraction (XRD) and infrared spectroscopy (IR) were performed to discuss the possible mechanism for the effect of citric acid towards CO methanation performance.  相似文献   

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