An understanding of the support effect is fundamental for guiding the rational design of heterogeneous catalysts. Herein, the role of pore structure on metal dispersion and catalytic performance was comprehensively investigated using Ni/Al₂O₃ catalysts. Three different Al₂O₃ supports, including Al₂O₃ microspheres prepared in microchannels and two commercially available Al₂O₃ supports named Sample 1 and Sample 2, were used and the Ni/Al₂O₃ catalysts were prepared by wetness impregnation method. X-ray diffraction, transmission electron microscopy, H₂ temperature-programmed reduction, X-ray photoelectron spectroscopy, N₂ adsorption–desorption, and H₂ pulse chemisorption analyses combined with a sintering kinetic model were used to investigate the effect of the support pore structure. The narrow pore size distribution (3–15 nm) of Al₂O₃ microspheres and Sample 1 led to a uniform NiO dispersion for the calcined catalysts. Moreover, the high specific surface area (291 m²/g) and large pore volume (1.0 mL/g) of the Al₂O₃ microspheres were beneficial for the deposition of NiO particles inside mesopore to obtain a stronger metal–support interaction. Owing to the smaller NiO nanoparticles and stronger metal–support interaction, the reduced Ni/Al₂O₃ microspheres exhibited an average Ni particle size of 10.2 nm under 36 wt% nickel loading, whereas the average Ni particle size loaded on Sample 1 and Sample 2 were 12.6 nm and 13.2 nm, respectively. The optimized CO₂ conversion of 87.0% at 300 °C under atmospheric pressure was attributed to the large pore volume and uniform Ni dispersion of Ni/Al₂O₃ microsphere catalysts while the same value for Sample 1 and Sample 2 catalysts was 81.5% and 55.0%, respectively. This work provides valuable guidelines for designing effective CO₂ methanation support and proves the potential application of Al₂O₃ microspheres for CO₂ methanation.

对载体效应的理解是指导多相催化剂合理设计的基础。_{在此，使用Ni/Al 2} O ₃催化剂全面研究了孔结构对金属分散和催化性能的作用。使用三种不同的Al ₂ O ₃载体，包括在微通道中制备的Al ₂ O ₃微球和两种市售的Al ₂ O ₃载体，分别命名为样品1和样品2，并通过湿浸渍法制备了Ni/Al ₂ O ₃催化剂。 . X射线衍射，透射电子显微镜，H ₂程序升温还原、X射线光电子能谱、N ₂吸附-解吸和H ₂脉冲化学吸附分析结合烧结动力学模型来研究载体孔结构的影响。_{Al 2} O ₃微球和样品 1的窄孔径分布（3-15 nm）导致煅烧催化剂的 NiO 分散均匀。_{此外，Al 2} O ₃的高比表面积（291 m ² /g）和大孔体积（1.0 mL/g）微球有利于NiO颗粒在中孔内的沉积，以获得更强的金属-载体相互作用。由于更小的 NiO 纳米颗粒和更强的金属-载体相互作用，还原的 Ni/Al ₂ O ₃微球在 36 wt% 的镍负载下表现出 10.2 nm 的平均 Ni 粒径，而负载在样品 1 和样品上的平均 Ni 粒径2 分别为 12.6 nm 和 13.2 nm。在大气压下 300 °C 时优化的 CO _{2转化率为 87.0%，这归因于 Ni/Al 2} O _{3的大孔体积和均匀的 Ni 分散}微球催化剂，而样品 1 和样品 2 催化剂的相同值分别为 81.5% 和 55.0%。这项工作为设计有效的 CO ₂甲烷化载体提供了有价值的指导，并证明了 Al ₂ O ₃微球在 CO ₂甲烷化中的潜在应用。