Unveiling The Nature Of Room-Temperature O-2 Activation And O-2(Center Dot-) Enrichment On Mgo-Loaded Porous Carbons With Efficient H2s Oxidation

The activation of O-2 into the dioxide radical (O-2(center dot-)) at room temperature serves as a critical chemical process implicated in environmental remediation and industrial chemical processes, but the involved mechanism remains unclear. Herein, we address this challenge by the radical detection method combined with DFT study and unveil that the O-2 activation reaction could take place merely in porous carbons (PCs) at room temperature. DFT calculations indicate that sp(2)-conjugated carbons can transfer a pi* electron to the outer orbit of the O-2 molecule derived by the space confinement in ultramicropores (similar to 0.4 nm), and the presence of edge site defects and heterogeneous atoms can facilitate the electron transfer due to increased quantity of free electrons. The produced O-2(center dot-) radicals could be further trapped and enriched on the surface of MgO as predicted by DFT calculations, which is subsequently confirmed by radical detection analysis of the designed MgO-loaded PCs. Furthermore, the O-2 activation and O-2(center dot-) enrichment on MgO-loaded PCs are applied in a probe reaction of room-temperature catalytic H2S oxidation, in which an outstanding catalytic performance is achieved. These findings provide valuable insight into the intrinsic origin of the O-2 activation at room temperature and open a fresh route to efficient formation and concentration of O-2(center dot-) for aerobic oxidization processes.