Carbon dioxide reforming of methane over promoted NixMg1−xO (111) platelet catalyst derived from solvothermal synthesis
Carbon dioxide reforming of methane over promoted NixMg1−xO (111) platelet catalyst derived from solvothermal synthesis
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DOI：
10.1016/j.apcatb.2013.10.046
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发表时间：
2014-04
影响因子：
22.1
通讯作者：
Mingjue Yu;Kake Zhu;Zhicheng Liu;Haipeng Xiao;Wei Deng;Xinggui Zhou
中科院分区：
文献类型：
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作者：
Mingjue Yu;Kake Zhu;Zhicheng Liu;Haipeng Xiao;Wei Deng;Xinggui Zhou
提出了一种自下而上的方法来合成由Tasker III型极性（11 11 1）面包裹的Sn， Ce， Mn或Co促进的NixMg1−xO催化剂。Sn和Co均匀分布在NixMg1−xO上，而Ce和Mn则以单独的氧化物形式析出。通过x射线衍射（XRD）， n2物理吸附，x射线光电子能谱（XPS）和透射电子显微镜（TEM）测量来了解新鲜和废催化剂的结构/组成。采用h2 -温度程序加氢（TPH）、XPS和热重分析（TG）分析了废催化剂上形成的焦炭类型。Mn对c β形成的催化稳定性没有明显的增强作用，Mn从催化剂表面分离，导致NixMg1−xO（11 11）血小板团聚，活性降低。Ce促进NixMg1−xO（11 11 1）催化剂中发现了c β和晶须碳，因为Ce以CeO2的形式分离。在ch4 - co2干重整过程中，Sn和Co均能抑制Cβ的生成，从而提高NixMg1−xO催化剂的抗焦性能。活化能（Ea）测量表明，Sn降低了Ni表面的活度，而Co没有钝化Ni表面的本构活度。在CH4/ co2比为3且无稀释气体的条件下，Co可以提高NixMg1−xO（11 11）催化剂的寿命。
A bottom-up approach is developed to synthesize Sn, Ce, Mn, or Co promoted NixMg1−xO catalysts enclosed by Tasker III type polar (1 1 1) facets. Sn and Co are evenly distributed on NixMg1−xO, whereas Ce and Mn segregate as separate oxides. X-ray diffraction (XRD), N2physisorption, X-ray photoelectron spectroscopy (XPS), and Transmission Electron Microscopic (TEM) measurements are carried out to understand the structure/composition of both fresh and spent catalysts. H2-Temperature Programmed Hydrogenation (TPH), XPS and Thermogravimetric analysis (TG) are employed to elucidate the types of coke formed on the spent catalysts. Mn does not show obvious enhancement to catalytic stability towards Cβformation, and a lower activity is observed as it separates from catalyst surface and causes agglomeration of NixMg1−xO(1 1 1) platelets. Cβand whisker carbons are found for Ce-promoted NixMg1−xO(1 1 1) catalyst, for Ce segregates as CeO2. Both Sn and Co are distinguished to enhance the coke-resistant properties of NixMg1−xO catalyst in CH4-CO2dry reforming, as they inhibit the formation of Cβ. Activation energy (Ea) measurements show that Sn lowers the activity of Ni surfaces, while Co does not passivate the intrinsic activity of Ni surfaces. Under more critical reaction conditions with CH4/CO2ratio of 3 and diluent gas free, Co is found to enhance the lifespan of NixMg1−xO (1 1 1) catalyst.