Development of high-performance nickel-based catalysts for production of hydrogen and carbon nanotubes from biogas

Selecting a suitable catalyst for implementing both simultaneous productions of hydrogen-rich syngas and multi-walled carbon nanotubes (MWCNTs) 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 4 and CO 2 conversions of biogas in a fixed bed reactor at 800°C and atmospheric pressure. Among the catalysts investigated for directly converting biogas process, the bimetallic NiMo/MgO catalyst showed the outstanding catalytic performance with 86.4% CH 4 conversion and 95.6% CO 2 conversion as well as producing the highest syngas purity of 90.0% with H 2 /CO ratio = 1.1. Moreover, the characterization of the synthesized CNTs proved that the well-aligned structured morphology, high purity, and excellent textural properties were obtained using NiMo/MgO catalyst. On the other hand, using trimetallic catalysts which have the composition of Co and Fe particles leads to severe deactivation. This could be elucidated by the influence of the catalyst oxidation with CO 2 in biogas, resulting in the transformation of metal into large metal oxide. The integrative process through using NiMo/MgO catalysts is regarded as a promising pathway, which has potentially useful for directly converting biogas into a high value-added product and provides a management approach for the enormous amounts of wastes.