Carbon nanotubes are studied as catalyst supports in biphasic (oil and water) systems. In the first part the relationships between a carbon nanotubes properties before and after functionalization and the influence those properties have on emulsions characteristics is studied. Emulsion characteristics studied were emulsion type, droplet size, interfacial area, and quantity of carbon nanotubes at the oil-water interface. Emulsions stabilized with carbon nanotubes are compared with emulsions stabilized with silica nanoparticles to further understand how material properties influence emulsion characteristics. The relationship between carbon nanotubes and silica nanoparticles properties and emulsion characteristics is utilized to control reaction selectivity, further understand the particles environment at the oil-water interface, and create a responsive system where reaction selectivity can be tuned as the reaction proceeds. Finally, with the ability to synthesize carbon nanotubes with different properties a novel catalyst is made which can determine the location of the active site for bifunctional catalysts.