Nanomaterial-based catalysts are usually heterogeneous catalysts divided into nanoparticles to speed up the catalytic process. The extremely small size of the particles increases the surface area exposed to the reactant, allowing more reactions to occur at the same time, thus speeding up the process. Much research on nanomaterialbased catalysts concerns maximizing the effectiveness of the catalyst coating in fuel cells. Platinum, the most common catalyst for this application, is rare and costly. A great deal of research hopes to maximize the catalytic properties of less expensive metals by shrinking them to nanoparticles.