Hollow mesoporous carbon cubes with high activity towards the electrocatalytic reduction of oxygen.

Hollow-structured mesoporous carbon cubes (HMCCs) have been successfully synthesized from carbon dioxide by a facile approach based on thermal reduction of magnesium. The approach is economical and applicable to large-scale synthesis. Notably, pyrrole-type nitrogen species are doped into the HMCCs during the synthesis in situ, that is, without introducing a nitrogen-containing precursor. A formation mechanism of the HMCCs is proposed, and formation of the structure is attributed to MgO templates generated in situ. Furthermore, the HMCCs are demonstrated to be a promising alternative to commercial Pt/C fuel-cell catalysts for the electrochemical oxygen reduction reaction.