Effects of composite oxide supports on catalytic performance of Ni-based catalysts for CO methanation

Metal-oxide-modified NiO/Al2O3 catalysts for methanation of CO were prepared using a modified grinding-mixing method and characterized using X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, temperature-programmed reduction by H2, temperature-programmed desorption by H2, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results show that the activity of an MgO-modified NiO/Al2O3 catalyst is better than those of NiO/ZrO2-Al2O3 and NiO/SiO2-Al2O3 in the reaction temperature range 300–700 °C. The incorporation of a metal oxide into NiO/Al2O3 was found to weaken Ni–Al interactions, leading to generation of large numbers of active Ni species, and this was confirmed to be responsible for the improvement in the performances of the catalysts in the methanation reaction.

摘要采用改良的粉末混合法制备了系列经过其它金属氧化物改性的 NiO/Al2O3 催化剂, 并运用 X 射线衍射、透射电子显微镜、N2 低温物理吸附-脱附、程序升温还原、程序升温脱附、拉曼以及 X 射线光电子能谱对催化剂进行了表征. 结果显示, 在 300–700 oC 经 MgO 修饰的 NiO/Al2O3 催化剂上 CO 甲烷化反应活性比 NiO/ZrO2-Al2O3 和 NiO/SiO2-Al2O3 的高. 另一金属氧化物的加入削弱了 NiO/Al2O3 催化剂中 Ni-Al 间相互作用, 形成更多的活性 Ni 物种, 从而促进了反应的进行.

Graphical AbstractNiO/MOx-Al2O3 (M = Mg, Si, Zr) catalysts for CO methanation, prepared using a modified grinding-mixing method, have higher catalytic activities than that of a conventional NiO/Al2O3 catalyst. This is attributed to the weakening of Ni-Al interactions after adding MOx.Figure optionsDownload as PowerPoint slide