Fluidization is an important operation for multiphase reactions, especially for gas-phase catalytic reactions because it provides a large solid surface area for improved gas-solid contact efficiency. Although fine particles with small particle size (<45 mu m) could be more desirable in providing larger interfacial area, their strong interparticle forces lead to poor or even no fluidization. In this project, a "nanomodification" technique has been adopted to reduce the interparticle forces so as to release the potential of fine particles in multiphase reactions. As a first attempt, "nano modified" fine catalysts (32 mu m) were used in the ozone decomposition reaction and displayed better reaction performance than regular catalysts due to larger interfacial area and more gas holdup in the bed, indicating better gas-solid contact. The reaction conversion and contact efficiency using the nanomodified fine fluid cracking catalytic (FCC) catalysts significantly increased compared to that of using regular FCC catalysts (100 mu m).