Chemical-looping methane decomposition using activated carbon as a catalyst has been considered a potentially promising approach for high-purity H₂ production with low cost and low CO₂ emission. However, activated carbon is known to deactivate fast despite its high initial catalytic activity. Oppositely, carbon black has shown stable catalytic methane decomposition that even increases slowly with time of reaction. Considering these two different activity trends, activated carbon and carbon black are jointly used to prepare catalysts and then test for the decomposition of the methane via chemical looping in this study that aimed to examine catalyst and reaction properties which may combine the high initial activity of activated carbon with the steady-and-increasing activity of carbon black. These mixed catalysts are examined using X-ray diffraction analysis (XRD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), Brunauer-Emmett-Teller (BET) and high-resolution transmission electron microscopy (HRTEM) before and after reaction testing to reveal chemical and physical constituents which contributed to their reactivities, and the mechanism of long catalytic activity has been discussed. The results point to insights and potential directions for modifying carbonaceous catalysts for chemical looping thermo-catalytic decomposition of methane.

使用活性炭作为催化剂的化学环甲烷分解被认为是低成本，低CO _2的高纯度H ₂生产的潜在有前途的方法排放。然而，已知活性炭尽管具有很高的初始催化活性，但仍会迅速失活。相反，炭黑显示出稳定的催化甲烷分解，甚至随着反应时间而缓慢增加。考虑到这两种不同的活性趋势，本研究旨在将活性炭和炭黑共同用于制备催化剂，然后通过化学循环测试甲烷的分解，该研究旨在检查催化剂和反应特性，这些特性可能结合了活性炭的高初始活性。碳具有稳定且不断增加的炭黑活性。使用X射线衍射分析（XRD），扫描电子显微镜和能量色散光谱（SEM / EDS）检查这些混合催化剂，Brunauer-Emmett-Teller（BET）和高分辨率透射电子显微镜（HRTEM）在反应测试之前和之后揭示了有助于其反应活性的化学和物理成分，并讨论了长催化活性的机理。研究结果为改性碳质催化剂用于甲烷的化学循环热催化分解提供了见识和潜在的方向。