Department of Chemical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom, 73170, Thailand.
Center of Excellence in Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
Sci Rep. 2022 Sep 7;12(1):15195. doi: 10.1038/s41598-022-19638-y.
Selecting a suitable catalyst for implementing the simultaneous production of hydrogen-rich syngas and multi-walled carbon nanotubes through the integration of dry reforming and methane decomposition reactions has recently gained great interests. In this study, a series of bimetallic (NiMo/MgO) and trimetallic (CoNiMo/MgO, FeNiMo/MgO, CoFeMo/MgO) catalysts was prepared and evaluated for a catalytic activity of CH and CO conversions of biogas in a fixed bed reactor at 800 °C and atmospheric pressure. Among the investigated catalysts, the bimetallic NiMo/MgO catalyst showed the outstanding catalytic performance with 86.4% CH conversion and 95.6% CO conversion as well as producing the highest syngas purity of 90.0% with H/CO ratio = 1.1. Moreover, the characterization of the synthesized solid products proved that the well-aligned structured morphology, high purity, and excellent textural properties of CNTs were obtained by using NiMo/MgO catalyst. On the other hand, using trimetallic catalysts which have the composition of Co and Fe leads to the severe deactivation. This could be attributed the catalyst oxidation with CO in biogas, resulting in the transformation of metals into large metal oxides. The integrative process with NiMo/MgO catalyst is regarded as a promising pathway, which has a high potential for directly converting biogas into the high value-added products and providing a green approach for managing the enormous amounts of wastes.
选择合适的催化剂，通过整合干重整和甲烷分解反应，同时生产富氢合成气和多壁碳纳米管，最近引起了极大的兴趣。在这项研究中，我们制备了一系列双金属（NiMo/MgO）和三金属（CoNiMo/MgO、FeNiMo/MgO、CoFeMo/MgO）催化剂，并在 800°C 和常压下的固定床反应器中评估了它们对沼气中 CH 和 CO 转化的催化活性。在所研究的催化剂中，双金属 NiMo/MgO 催化剂表现出优异的催化性能，CH 转化率为 86.4%，CO 转化率为 95.6%，产生的合成气纯度最高，H/CO 比为 1.1。此外，合成固体产物的表征证明，使用 NiMo/MgO 催化剂可以获得具有良好取向结构形态、高纯度和优异织构特性的 CNTs。另一方面，使用含有 Co 和 Fe 的三金属催化剂会导致严重的失活。这可能归因于催化剂与沼气中的 CO 发生氧化，导致金属转化为大的金属氧化物。使用 NiMo/MgO 催化剂的集成工艺被认为是一种很有前途的途径，它具有将沼气直接转化为高附加值产品的巨大潜力，并为处理大量废物提供了一种绿色方法。
