Figure 2
From: Layered SiC Sheets: A Potential Catalyst for Oxygen Reduction Reaction

Minimum energy pathways for ORR elemental steps in acidic media on a single-layer SiC: (a) O2 → 2O, (b) 2O + H → O + OH, (c) O + OH + H → O + H2O, (d) O + H → OH, (e) OH + H → H2O and (f) schematic energy profile.
IS, TS and FS are initial, transition and final states, respectively. Gray, gold, white and red colors denote C, Si, H and O atoms.