Nitrogen-Doped Mesoporous Carbon as Electrocatalysts for Oxygen Reduction Reaction

Carbon materials modified with nonmetallic elements, such as boron, fluorine, nitrogen, phosphorus, and sulfur, are commonly named as doped carbons, which are an emerging class of materials to be employed in electrocatalysis. Among all nonmetallic doped carbon, nitrogen-doped carbons (NC) are of particular interest since they showed potential employment as catalytic material for oxygen reduction reaction. NC catalysts essentially contain nitrogen incorporated in the carbon structure, either at the edges or within the core structure of the carbon material by replacing one of the sp2-hybridized carbon atoms into the graphitic structure. NC were intensively investigated as cost-effective material for replacing costly catalysts in some vital reactions, for example, as substitutes for platinum for the oxygen reduction reaction in fuel cells or in metal/air batteries, even though O2 is principally reduced to H2O2 when metal-free NC are employed. Among many NC materials nitrogen-doped mesoporous carbons are of particular interest because they conciliate the catalytic activity of a NC, with the surface morphology and mass transport properties necessary in gas diffusion electrodes. This book chapter deals with the synthesis, characterization, and activity of nitrogen-doped mesoporous carbons with a special emphasis on the role that nitrogen functional groups play in oxygen reduction reaction.