Ultrasmall Mo2C Embedded in N‐Doped Holey Carbon for High‐Efficiency Electrochemical Oxygen Reduction Reaction

Abstract The Oxygen reduction reaction (ORR) plays an important role in fuel cells, but the synthesis of efficient and low‐cost catalysts remains challenging. We report the synthesis of ultra‐small Mo 2 C nanoparticles with an average size of 1.5 nm embedded in a N‐doped holey carbon (NHC) matrix by employing self‐assembled macrocycle cucurbit[6]uril (CB[6]) and melamine as carbon precursors. The interaction between Mo precursors and CB[6] effectively prevented the aggregation of Mo 2 C NPs during the pyrolysis procedure. Besides, the holey structural carbon has a larger electrocatalytic activity area and improves mass transfer efficiency and charge transfer rate. The NHC features abundant defective sites and thus effective anchoring and electronic regulation for Mo 2 C nanoparticles. The electrochemical oxygen reduction activity of Mo 2 C/NHC is comparable to that of noble metal Pt/C benchmark catalyst with an initial potential, half‐wave potential and limiting current density of 0.95 V, 0.84 V and 5.0 mA cm −2 , respectively. Mo 2 C/NHC shows a good long‐term durability during 25 h chronoamperometry.