Novel carbon structures as highly stable supports for electrocatalysts in acid media: regulating the oxygen functionalization behavior of carbon

Abstract

The nature of the carbon support has huge effects on the catalytic properties of supported catalysts. When utilized for electrochemical purposes as a support for precious metals in acid media, the oxygen functionalization behavior is even more vital to the stability of carbon because of the acceleration of carbon oxidation by precious metals. Here, we demonstrate the regulation of oxygen functionalization behavior of carbon via introducing Co during the fabrication process, and the resultant N-doped hollow carbon embedded with Co (NHC@Co) greatly boosts the catalytic stability of Pt/NHC@Co in the oxygen reduction reaction (ORR). On the one hand, the utilization of Co during fabrication promotes the graphitic level of carbon, which provides fewer anchoring points for adsorbed oxygen, and on the other hand, the remaining Co nanoparticles exhibit strong electron donating effects, which upshifts the Fermi level of C and strengthens its bonding with oxygen. As a result, a small amount of oxygen functional groups is bonded strongly on the surface of NHC@Co, hindering the further catalytic oxidation of carbon and improving the electrochemical stability of Pt/NHC@Co even under harsh acidic ORR conditions.