Preparation and Characterization of Zirconia-Coated Nanodiamonds as a Pt Catalyst Support for Methanol Electro-Oxidation

Zirconia-coated nanodiamond (ZrO(2)/ND) electrode material was successfully prepared by one-step isothermal hydrolyzing from ND-dispersed ZrOCl(2)·8H(2)O aqueous solution. High-resolution transmission electron microscopy reveals that a highly conformal and uniform ZrO(2) shell was deposited on NDs by this simple method. The coating obtained at 90 °C without further calcination was mainly composed of monoclinic nanocrystalline ZrO(2) rather than common amorphous Zr(OH)(4) clusters. The ZrO(2)/NDs and pristine ND powder were decorated with platinum (Pt) nanoparticles by electrodeposition from 5 mM chloroplatinic acid solution. The electrochemical studies indicate that Pt/ZrO(2)/ND catalysts have higher electrocatalytic activity and better stability for methanol oxidation than Pt/ND catalysts in acid.