Performance of low-concentration methane combustion catalyzed by Co₃O₄

To explore a facile and eco-friendly synthesis route for Co₃O₄, the Co₃O₄ catalysts were synthesized by the solid-phase method using cobalt acetate and oxalic acid as precursors, and its catalytic performance for the combustion of low-concentration methane was evaluated. The catalysts were characterized by X-ray diffraction （XRD）, H₂ temperature-programmed reduction （H₂-TPR）, N₂ physisorption, and scanning electron microscopy （SEM）. The activity and reaction kinetics of Co₃O₄ in catalytic methane combustion were subsequently investigated. The results revealed that the optimal synthesis conditions included a cobalt acetate-to-oxalic acid molar ratio of 1:3, calcination at 400 ℃ for 4 h, and grinding for 10 min. The obtained catalyst exhibited a pure Co₃O₄ phase, with surface Co³⁺ species identified as critical active sites for enhancing catalytic performance. Under a gas hourly space velocity （GHSV） of 467 mL·gcat⁻¹·min⁻¹, the temperatures corresponding to 50% （T₅₀） and 90% （T₉₀） methane conversion were 367 ℃ and 437 ℃, respectively. The apparent activation energy （Eₐ） was determined to be 99.67 kJ·mol⁻¹. This study offers a practical strategy for optimizing Co₃O₄-based catalysts and advancing the utilization of low-concentration methane sources, particularly coal mine ventilation air methane （VAM）.