Abstract:
To explore a facile and eco-friendly synthesis route for Co
3O
4, the Co
3O
4 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), H
2 temperature-programmed reduction (H
2-TPR), N
2 physisorption, and scanning electron microscopy (SEM). The activity and reaction kinetics of Co
3O
4 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 Co
3O
4 phase, with surface Co
3+ 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 Co
3O
4-based catalysts and advancing the utilization of low-concentration methane sources, particularly coal mine ventilation air methane (VAM).