共查询到19条相似文献,搜索用时 78 毫秒
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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
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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
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
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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
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
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Luo Laitao Li Songjun Deng Gengfeng Li Fengyi 《Reaction Kinetics and Catalysis Letters》2002,75(2):289-296
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
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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
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LaitaoLuo SongjunLi YanOuyang 《天然气化学杂志》2003,12(4):254-258
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
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LaitaoLuo SongjunLi 《天然气化学杂志》2004,13(1):45-48
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
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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
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The effect of citric acid on the catalytic activity of nano‐sized MoS2 toward sulfur‐resistant CO methanation 下载免费PDF全文
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