2 CH4 (g) + O2 (g) → 4 H2 (g) + 2 CO (g)
This is an oxidation-reduction (redox) reaction:
2 C-IV - 12 e- → 2 CII (oxidation)
8 HI + 8 e- → 8 H0 (reduction)
2 O0 + 4 e- → 2 O-II (reduction)
CH4 is a reducing agent, CH4 is an oxidizing agent, O2 is an oxidizing agent.