Several factors influence the diffusion coefficient (D), including:
Temperature: Higher temperatures generally increase the diffusion coefficient. Molecular Size: Larger molecules diffuse more slowly than smaller ones. Medium Viscosity: Higher viscosity fluids impede diffusion, reducing D. Pore Structure: In porous materials, pore size, tortuosity, and connectivity affect De.
By controlling these factors, one can optimize the diffusional characteristics of a catalyst.
