A series of MoO_x doped Ni/3D-SBA-15 catalysts with a three-dimensional network structure were prepared by an impregnation method using different solvents for CO methanation. It is a challenge to simultaneously improve the low-temperature activity and long-term stability of the catalyst for a high-temperature reaction. In this work, MoO_x-doped Ni/3D-SBA-15 catalysts with a three-dimensional network structure were prepared by an impregnation method using ethylene glycol as a solvent for the CO methanation reaction. In addition, H₂O was used as a solvent for comparison. The catalyst prepared in the presence of ethylene glycol, shows high specific surface area, small Ni particle size, and high metal dispersion. The addition of the Mo promoter can further improve Ni dispersion and decrease the interaction between NiO species and the support. After reduction under a H₂ flow at 600 °C, the Mo promoter is in the mixed valencies in the form of MoO_x (x < 3), which can increase the density of Ni atomic electron clouds. As a result, the Ni–MoO_x/3D-SBA-15 catalyst exhibits the highest low-temperature activity, whose CO conversion reaches 99.3% at 320 °C, 0.1 MPa, and 60 000 mL g⁻¹ h⁻¹. During the 100 h-lifetime test, this catalyst exhibits high stability due to the small Ni particle size, appropriate metal-support interaction, the promotion of MoO_x species as well as the confinement effect of 3D-SBA-15 support.

中文翻译：

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MoOx掺杂的Ni / 3D-SBA-15催化剂用于CO甲烷化：溶剂和MoOx助催化剂对催化性能的影响

通过浸渍法，使用不同的溶剂进行CO甲烷化，制备了一系列具有三维网络结构的MoO _x掺杂的Ni / 3D-SBA-15催化剂。同时提高用于高温反应的催化剂的低温活性和长期稳定性是一个挑战。在这项工作中，通过浸渍法使用乙二醇作为CO甲烷化反应的溶剂，制备了具有三维网络结构的MoO _x掺杂的Ni / 3D-SBA-15催化剂。另外，H ₂O用作溶剂进行比较。在乙二醇存在下制备的催化剂显示出高的比表面积，小的Ni粒径和高的金属分散性。Mo助催化剂的添加可以进一步改善Ni的分散并降低NiO物质与载体之间的相互作用。在600°C的H ₂气流中还原后，Mo助催化剂以MoO _x（x <3）的形式处于混合价态，这可以增加Ni原子电子云的密度。结果，Ni-MoO _x / 3D-SBA-15催化剂表现出最高的低温活性，其在320°C，0.1 MPa和60 000 mL g ^-1 h ^-1的条件下CO转化率达到99.3％。在100小时的寿命测试中，由于Ni的粒径小，金属与载体之间的适当相互作用，MoO _x种类的促进以及3D-SBA-15载体的限制作用，该催化剂具有很高的稳定性。