Nitrogen-doped ordered mesoporous carbons as electrocatalysts for methanol-tolerant oxygen reduction in acid solution

A simple method is described for the production of Pt supported on nitrogen-doped ordered mesoporous carbons (Pt-OMCN(x)) by the pyrolysis of carbon and metal precursors in a N-containing organo-functionalized mesoporous silica as the primary N sources and hard templates. The resultant Pt-OMCN(x) samples were thoroughly characterized by a variety of different spectroscopic and analytical techniques. Results obtained from X-ray diffraction, N(2) adsorption/desorption isotherms and transmission electron microscopy show that Pt-OMCN(x) possessed well-dispersed Pt nanoparticles (2-3 nm) supported on high surface area (450 m(2) g(-1)) and regular pore channels (2.5 nm). Elemental analysis and X-ray photoelectron spectroscopy indicate that ca. 1.8 wt% of N species presented on the carbon rods of Pt-OMCN(x) were mostly quaternary-N (55%) and pyridinic-N (45%). The Pt-OMCN(x) was found to have superior electrocatalytic activity and the tolerance to methanol crossover during the oxygen reduction reaction (ORR), which can be attributed to the dispersion and unique nanostructure of Pt nanoparticles particularly in the presence of pyridinic-N atoms in the mesoporous carbon supports. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.