High-Performance Electrocatalysts for Oxygen Reduction Based on Nitrogen-Doped Porous Carbon from Hydrothermal Treatment of Glucose and Dicyandiamide

A synthetic method was developed for the preparation of N-doped porous carbon through hydrothermal treatment at controlled temperatures by using glucose and dicyandiamide as precursors and ZnCl2 as an activation reagent. Nitrogen doping was quantitatively determined by using XPS measurements and identified in the forms of pyridinic, pyrrolic, graphitic, and pyridinic N+-O- nitrogen atoms. Further structural analysis by using SEM, TEM, XRD, Raman, FTIR, and BET measurements showed that the N-doped porous carbons exhibited a micro-crystalline graphite structure and a high specific surface area up to 1000 m(2)g(-1). Electrochemical studies showed that the samples all exhibited a remarkable ORR catalytic activity in alkaline media, which was comparable to that of state-of-the-art Pt/C catalysts, and the one prepared at 800 degrees C was found to be the best among the series with an onset potential of +0.96 V, almost complete reduction of oxygen to OH-, and superior methanol tolerance and cycling stability.