Graphitized Nanodiamond as Highly Efficient Support of Electrocatalysts for Oxygen Reduction Reaction

Graphitized nanodiamond (GND) with a nanodiamond (ND) core covered by a graphitic shell was used as a stable support of platinum (Pt) electrocatalysts for oxygen reduction reaction (ORR). ND particles were annealed at 1300 and 1600°C in a vacuum of 10−3 Pa, and a graphitic shell formed on ND's surface (GND1300, GND1600). The core-shell structure improves ND's conductivity and also retains its high electrochemical stability. GND supported Pt electrocatalysts were prepared using a microwave heating polyol method. The catalytic activity of Pt/GND1600 for ORR was better than traditional Vulcan XC-72 carbon supported Pt (Pt/C) catalysts. The accelerated durability test results showed that the Pt/GND1600 had greater stability in comparison to Pt/GND1300 and Pt/C, which was ascribed to the high stability of the GND1600 support in acid solution and strong interaction with Pt NPs.