Pt nanoparticles supported on carbon nanowalls with different domain sizes for oxygen reduction reaction

Abstract

Carbon nanowalls (CNWs) with different domain sizes were synthesized by a dc plasma-enhanced chemical vapor deposition. Platinum (Pt) loading on the CNWs (Pt/CNW) was carried out by a solution reduction method. As a result, Pt nanoparticles were preferentially deposited along the domain boundaries in CNWs as reported previously. It should be noted that the Pt particle size strongly depends on the domain size. Namely, the smaller the domain size is, the smaller the Pt particle size is. Moreover, the Pt/CNW with smaller Pt particles exhibit high catalytic activity. Especially, the mass activity related to cathodic oxygen reduction reaction (ORR) is high and reach about five times as much as that of commercial T-Pt/CB with good performance. The high ORR activity can be attributed to the domain boundaries in CNWs, which might lower not only the activation energy of O2 dissociation on Pt particles but also the energy barrier of the rate-limiting step in the ORR process.