一锅法制备高活性高稳定性Ni-Nd-Al三元有序介孔甲烷化催化剂

发布时间：2018-09-18 14:52

【摘要】：CO甲烷化在煤制天然气技术中起着重要作用,Ni基催化剂作为目前研究最多的甲烷化催化剂,仍存在低温活性差、高温易烧结和易积炭等问题。针对这些问题,采用改进的溶剂蒸发诱导自组装方法,设计制备了不同含量Nd物种修饰的Ni-Nd-Al三元有序介孔甲烷化催化剂。采用N_2-物理吸附、X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等分析方法对反应前后催化剂的结构和形貌进行了表征,并考察其CO甲烷化反应催化性能。结果表明,制备出的Ni-Nd-Al甲烷化催化剂均具有有序介孔结构,Ni和Nd物种均匀分布在孔道内。适量Nd物种的加入有助于减小Ni颗粒的尺寸,提高其分散度和对H_2的吸附能力,进而提升催化剂的活性。有序介孔结构的限域效应有助于提高催化剂抗烧结和抗积炭能力。
[Abstract]:CO methanation plays an important role in the production of natural gas from coal. As the most studied methanation catalyst, there are still some problems such as poor activity at low temperature, easy sintering at high temperature and easy carbon deposition. To solve these problems, the ternary ordered mesoporous methanation catalyst of Ni-Nd-Al modified with different Nd species was designed and prepared by an improved solvent vaporization induced self-assembly method. The structure and morphology of the catalysts before and after the reaction were characterized by means of N2-physical adsorption X-ray diffraction (XRD) X-ray photoelectron spectroscopy (XPS),) (XPS), scanning electron microscopy (SEM) (SEM), transmission electron microscopy (TEM) and their catalytic properties of CO methanation were investigated. The results show that the prepared Ni-Nd-Al methanation catalysts all have ordered mesoporous structure Ni and Nd species uniformly distributed in the pore channel. The addition of appropriate amount of Nd species can reduce the size of Ni particles, increase its dispersion and adsorption ability to H2, and then enhance the activity of the catalyst. The limiting effect of ordered mesoporous structure is helpful to improve the sintering resistance and carbon deposition of the catalyst.
【作者单位】：中国科学院过程工程研究所多相复杂系统国家重点实验室;中国科学院大学;齐齐哈尔大学化学与化学工程学院;
【基金】：国家自然科学基金项目(21476238) 国家重点基础研究发展计划项目(2014CB744306) 多相复杂系统国家重点实验室自主部署课题项目(MPCS-2015-A-06)~~
【分类号】：TQ426

【相似文献】