Transition from heterogeneous catalytic reaction to homogeneous one by variation of palladium particle size

Reduction rate constants of methylene blue with hydrazine catalyzed by dispersed palladium particles were proportional to r03α, where 3α varied from 2 to 3 with a decrease in the radii of Pd particles. The estimated reaction layer thickness was independent of the radii, according to the diffusion-reaction model.