Simultaneous production of syngas and carbon nanotubes from CO<inf>2</inf>/CH<inf>4</inf> mixture over high-performance NiMo/MgO catalyst
Issued Date
2024-12-01
Resource Type
eISSN
20452322
Scopus ID
2-s2.0-85198660214
Journal Title
Scientific Reports
Volume
14
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Scientific Reports Vol.14 No.1 (2024)
Suggested Citation
Sae-tang N., Saconsint S., Srifa A., Koo-Amornpattana W., Assabumrungrat S., Fukuhara C., Ratchahat S. Simultaneous production of syngas and carbon nanotubes from CO<inf>2</inf>/CH<inf>4</inf> mixture over high-performance NiMo/MgO catalyst. Scientific Reports Vol.14 No.1 (2024). doi:10.1038/s41598-024-66938-6 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/99763
Title
Simultaneous production of syngas and carbon nanotubes from CO<inf>2</inf>/CH<inf>4</inf> mixture over high-performance NiMo/MgO catalyst
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Abstract
Direct conversion of biogas via the integrative process of dry reforming of methane (DRM) and catalytic methane decomposition (CDM) has received a great attention as a promising green catalytic process for simultaneous production of syngas and carbon nanotubes (CNTs). In this work, the effects of reaction temperature of 700–1100 °C and CH4/CO2 ratio of biogas were investigated over NiMo/MgO catalyst in a fixed bed reactor under industrial feed condition of pure biogas. The reaction at 700 °C showed a rapid catalyst deactivation within 3 h due to the formation of amorphous carbon on catalyst surface. At higher temperature of 800–900 °C, the catalyst can perform the excellent performance for producing syngas and carbon nanotubes. Interestingly, the smallest diameter and the highest graphitization of CNTs was obtained at high temperature of 1000 °C, while elevating temperature to 1100 °C leads to agglomeration of Ni particles, resulting in a larger size of CNTs. The reaction temperature exhibits optimum at 800 °C, providing the highest CNTs yield with high graphitization, high syngas purity up to 90.04% with H2/CO ratio of 1.1, and high biogas conversion (XCH4 = 86.44%, XCO2 = 95.62%) with stable performance over 3 h. The typical composition biogas (CH4/CO2 = 1.5) is favorable for the integration process, while the CO2 rich biogas caused a larger grain size of catalyst and a formation of molybdenum oxide nanorods (MoO3). The long-term stability of NiMo/MgO catalyst at 800 °C showed a stable trend (> 20 h). The experimental findings confirm that NiMo/MgO can perform the excellent activity and high stability at the optimum condition, allowing the process to be more promising for practical applications.