Investigating the liquid transport kinetics of solid catalysts is of great importance for gaining a better understanding of the manufacturing and performance of such catalysts during reaction upon contact with the liquid. Terahertz pulsed imaging (TPI) coupled with a newly designed flow cell was used to quantify the rate of water ingress into α-alumina pellets with a range of different porosities. A wide range of compaction forces (cold compaction, 7–58 kN) and sintering conditions (no firing and sintering at 1200 and 1300 °C) was investigated to explore the optimal pellet microstructure, i.e. mechanically strong but sufficiently porous for fast liquid transport kinetics. The results confirm that both the microstructure characteristics, particularly porosity, as well as the surface properties, i.e. wettability, influence the liquid transport kinetics. Fitting the TPI penetration rates with a power law shows that the type of observed mass transport characteristics is consistent with Darcy flow. The Lucas–Washburn equation was used to calculate the hydraulic radius based on the transport data. In summary, the results demonstrate that TPI has great potential to study the liquid transport kinetics of porous ceramic catalysts and catalyst supports and that can comfortably quantify transport processes at rates of 250 μm s⁻¹ and beyond in such substrates for better quality control and optimised design and performance of such materials.

研究固体催化剂的液体输送动力学对于更好地理解在与液体接触时反应期间这种催化剂的制造和性能非常重要。太赫兹脉冲成像（TPI）结合新设计的流通池用于量化水进入α的速率-具有不同孔隙率范围的氧化铝颗粒。研究了广泛的压实力（冷压实，7–58 kN）和烧结条件（在1200和1300°C下不烧结和烧结），以探索最佳的颗粒微结构，即机械强度高但具有足够的多孔性，可实现快速的液体传输动力学。结果证实，微观结构特征，特别是孔隙率，以及表面性质，即润湿性，都影响液体的输送动力学。用幂定律拟合TPI的渗透率表明，所观察到的质量传输特征的类型与达西流一致。Lucas–Washburn方程用于根据运输数据计算水力半径。综上所述，此类基材中的^-1或更高含量可实现更好的质量控制以及此类材料的优化设计和性能。