Scaffold-Like Titanium Nitride Nanotubes with a Highly Conductive Porous Architecture as a Nanoparticle Catalyst Support for Oxygen Reduction

We designed a scaffold-like porous titanium nitride (TiN) nanotube (NT) as a catalyst support for Pt to facilitate the oxygen reduction reaction. Bulk titanium nitride, which is known as an electrically conductive material, is compatible with other metals. As the size of TiN particles decreases, however, they lose their intrinsic high electrical conductivity, due to a series of nanoparticle grain boundaries acting as electron reservoirs and traps. A designed grain-boundary-free scaffold-like porous TiN NT which is analogous to the shape of the one-dimensional porous human spine exhibits high electrical conductivity in spite of having a surface area similar to that of TiN nanoparticle (NPs). The electrical conductivity of TiN NTs is ca. 30-fold higher than that of spherical TiN NPs. The electrochemical oxygen reduction measurements between porous TiN NT and TiN NPs after Pt loading clearl…