Sulphur-Doped Ordered Mesoporous Carbon Hollow Spheres with High Catalytic Activity for the Oxygen Reduction Reaction and Exceptional Electrochemical Stability

Abstract

We reported the synthesis of novel and less explored methanol-functionalized Sulphur-Doped Ordered Mesoporous Carbon Hollow Spheres (S-OMCHS-F) as metal-free electrocatalyst for the Oxygen Reduction Reaction (ORR) in alkaline media. The catalytic activity of S-OMCHS-F showed a higher performance than non-doped Ordered Mesoporous Carbon Hollow Spheres (OMCHS), with an onset potential of 0.88 V, half-wave potential 0.81 V and a current density (j) of -1.49 mA cm-2 at 0.8 V (all potentials vs. RHE). Moreover, its electron transfer number was n= 3.9 with a H2O2 production of 3%. Furthermore, after accelerated degradation tests (3000 cycles, between 0.6 and 1.0 V), S-OMCHS-F showed an improvement in catalytic activity with onset potential of 0.88 V, half-wave potential of 0.82 V and j= -1.69 mA cm-2 at 0.8 V. Also, its n was of 3.9 with a production of H2O2 of ~2%.