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    Co3O4催化剂催化低浓度甲烷燃烧性能

    Performance of low-concentration methane combustion catalyzed by Co3O4

    • 摘要: 为了探究过程简单、环境友好的Co3O4制备方法及Co3O4催化低浓度甲烷燃烧性能,以乙酸钴和草酸为原料,采用固相法合成了Co3O4催化剂。在对催化剂进行X 射线衍射(XRD)、氢气程序升温还原(H2-TPR)、N2物理吸附、扫描电子显微镜(SEM)表征的基础上,研究了Co3O4催化低浓度甲烷燃烧的活性和反应动力学。结果表明,适宜的Co3O4催化剂制备条件为乙酸钴与草酸物质的量比为1∶3、焙烧温度为400 ℃、焙烧时间为4 h、研磨时间为10 min。制备的催化剂为纯净的Co3O4,催化剂表面Co3+物种对低浓度甲烷催化燃烧性能具有显著影响。反应空速为467 mL·g−1·min−1条件下,Co3O4催化低浓度甲烷燃烧T50T90分别为367 ℃和437 ℃,表观活化能Ea为99.67 kJ·mol−1。研究结果可为优化Co3O4制备及深入研究煤矿乏风瓦斯等低浓度甲烷资源化利用提供参考。

       

      Abstract: 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).

       

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