In general, Pt/C is most widely used catalyst because it has a large surface area for platinum anchoring, high electrical conductivity, and suitable pore structure for transferring reactant and product. However, carbon support undergoes carbon corrosion which is happened thermodynamically favored in fuel cell operation conditions. This phenomenon occurs at the surface of the carbon and it makes void places under the Pt nanoparticles. This mechanism causes losing electrochemical active sites. And there are also agglomeration and sintering of Pt particles on the carbon surface. Consequentially, carbon corrosion and platinum dissolution result in reduced electrochemical surface area (ECSA) and interferes long-term operations. Thus, electrochemically stable support materials need to be developed.
In various alternative material candidates, our group selected the TiO2 based support because it exhibits excellent chemical stability under severe acidic condition and offers the opportunity to modifying electronic structure of platinum particles. However, hindrances such as low electrical conductivity, catalytic activity, and surface area limit the direct use of TiO2 as a catalyst support. To remedy these drawbacks, we have designed carbon-titania composite support based electrocatalysts. These noble TiO2 – carbon hybrid support was synthesized from electrospun nanofibers and platinum nanoparticles are deposited on a support by microwave-assisted polyol process. Through our new approaches, we can obtain the electrocatalysts which have a unique 3D pore structure with higher surface area, modified electronic structure with increased intrinsic activity and extended cyclic durability.