What is the effect of catalyst shape on catalyst performance?

At high temperatures, steam reforming of natural gas on the catalyst surface is rapid and the reaction process is controlled by internal diffusion, so the apparent activity increases significantly with increasing catalyst geometry. The apparent activity of the small-particle catalyst increases due to the increased geometric surface and improved heat transfer in the tube, but its resistance also increases. The shape also has an impact on the activity, strength, resistance, and heat transfer properties of one-stage reforming catalysts. For example, ICI's G291HGS catalyst is in the shape of a 7-spoke wheel, which not only has a large geometrical outer surface, but also has a Y-shaped force structure in any cross-section, which is reasonable, and has high compressive strength; Toppe's R6727H catalyst is in the shape of a 7-hole column, which has an outer surface slightly larger than that of a ring-shaped catalyst, but has a low void ratio (high resistance), and the only advantage is its better loading performance; Shandong Wante's catalyst is in the shape of a 4-hole convex cylindrical honeycomb, with an increase in apparent activity, but its resistance increases. Shandong Avant's catalyst is a four-hole convex cylindrical honeycomb type, which has the characteristics of large outer surface, high void ratio, low resistance and uniform airflow distribution.