CO methanation plays an important role in production of synthetic natural gas from coal. Application of Ni-based catalysts was restricted due to poor activity at low temperature, coke forming and Ni particle sintering at high temperature. A series of Nd-decorated Ni-Nd-Al ordered mesoporous methanation catalysts were synthesized by improved solvent evaporation-induced self-assembly method, and their catalytic performances for CO methanation were investigated. N2 adsorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (SEM), bright-field transmission electron microscopy (TEM) were used to characterize structure and morphology of both fresh and used catalysts. The results showed that all Ni-Nd-Al catalysts had ordered mesoporous structures, in which Ni particles were anchored but Nd species were dispersed in the ordered mesoporous alumina channels. Addition of appropriate Nd contributed to size reduction and dispersion improvement of Ni particles, and adsorption enhancement of H2, such that catalytic performance was promoted. The confinement effect of ordered mesoporous channels attributed to better anti-coking and anti-sintering properties of catalysts.%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N2-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H2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.
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