Abstract The NiCe/Al2O3 catalysts with various nickel contents were prepared by impregnation method and applied for CO2 methanation. The catalysts were characterized by temperature-programmed reduction of H2 (H2-TPR) and X-ray diffraction (XRD) techniques, respectively. TPR results indicated that the increase of nickel loading weakened the interaction between NiO and Al2O3, and XRD results suggested that with the nickel content increasing, the particle size of nickel increased for the reduced catalysts. The results of catalytic performance showed that NiCe/Al2O3 with low nickel content displayed better CO2 conversion and CH4 yield than those of high nickel content at low temperature (250 ∼ 400 °C), indicating the high activity of small nickel particle for CO2 methanation. Meanwhile, the catalyst with 15 wt.% nickel loading exhibited the best CH4 yield of 61.8% at 450 °C, and as the nickel loading reached to 30 wt.%, the catalytic activity of the catalyst reduced remarkably. Hence, the amount of nickel in the catalyst had an important effect on its catalytic performance.

中文翻译：

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NiCe/Al2O3 催化剂上的 CO2 甲烷化：镍负载量和粒径对催化性能的影响

摘要 采用浸渍法制备了不同镍含量的NiCe/Al2O3催化剂，并应用于CO2甲烷化。催化剂分别通过 H2 (H2-TPR) 和 X 射线衍射 (XRD) 技术的程序升温还原进行表征。TPR结果表明镍负载量的增加削弱了NiO和Al2O3之间的相互作用，XRD结果表明随着镍含量的增加，还原催化剂的镍粒径增加。催化性能结果表明，低镍含量的NiCe/Al2O3在低温（250～400℃）下比高镍含量的NiCe/Al2O3表现出更好的CO2转化率和CH4产率，表明小镍颗粒对CO2甲烷化具有较高的活性。同时，催化剂含有 15 wt. % 镍负载量在 450 °C 时表现出最佳的 CH4 产率为 61.8%，当镍负载量达到 30 wt.% 时，催化剂的催化活性显着降低。因此，催化剂中镍的含量对其催化性能有重要影响。