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Studies on influence of hydrogen and carbon monoxide concentration on reduction progression behavior of molybdenum oxide catalyst

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dc.contributor.authorSamsuri A.en_US
dc.contributor.authorLatif M.N.en_US
dc.contributor.authorShamsuddin M.R.en_US
dc.contributor.authorSalleh F.en_US
dc.contributor.authorAbu Tahari M.N.en_US
dc.contributor.authorTengku Saharuddin T.S.en_US
dc.contributor.authorDzakaria N.en_US
dc.contributor.authorYarmo M.A.en_US
dc.date.accessioned2024-05-29T02:09:19Z
dc.date.available2024-05-29T02:09:19Z
dc.date.issued2020
dc.description.abstractTemperature programmed reduction (TPR) analysis was applied to investigate the chemical reduction progression behavior of molybdenum oxide (MoO3) catalyst. The composition and morphology of the reduced phases were characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM). The reduction progression of MoO3 catalyst was attained with different reductant types and concentration (10% H2/N2, 10% and 20% CO/N2 (%, v/v)). Two different modes of reduction process were applied. The first approach of reduction involved non-isothermal mode reduction up to 700 °C, while the second approach of reduction involved the isothermal mode reduction for 60 min at 700 °C. Hydrogen temperature programmed reduction (H2-TPR) results showed the reduction progression of three-stage reduction of MoO3 (Mo6+ → Mo5+ → Mo4+ → Mo0) with Mo5+ and Mo4+. XRD analysis confirmed the formation of Mo4O11 phase as an intermediate phase followed by MoO2 phase. After 60 min of isothermal reduction, peaks of metallic molybdenum (Mo) appeared. Whereas, FESEM analysis showed porous crater-like structure on the surface cracks of MoO2 layer which led to the growth of Mo phase. Meanwhile, the reduction of MoO3 catalyst in 10% carbon monoxide (CO) showed the formation of unstable intermediate phase of Mo9O26 at the early stage of reduction. Furthermore, by increasing 20% CO led to the carburization of MoO2 phase, resulted in the formation of Mo2C rather than the formation of metallic Mo, as confirmed by XPS analysis. Therefore, the presented study shows that hydrogen gave better reducibility due to smaller molecular size, which contributed to high diffusion rate and achieved deeper penetration into the MoO3 catalyst compared to carbon monoxide reductant. Hence, the reduction of MoO3 in carbon monoxide atmosphere promoted the formation of Mo2C which was in agreement with the thermodynamic assessment. © 2020 Hydrogen Energy Publications LLCen_US
dc.identifier.doi10.1016/j.ijhydene.2020.08.214
dc.identifier.issn3603199
dc.identifier.scopus2-s2.0-85091494912
dc.identifier.urihttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85091494912&doi=10.1016%2fj.ijhydene.2020.08.214&partnerID=40&md5=2b09e865e4a278d43d94d2089c169322
dc.identifier.urihttps://oarep.usim.edu.my/handle/123456789/10459
dc.languageEnglish
dc.language.isoen_USen_US
dc.publisherElsevier Ltden_US
dc.relation.ispartofAIMS Microbiologyen_US
dc.sourceScopus
dc.subjectCarbon monoxideen_US
dc.subjectHydrogenen_US
dc.subjectMolybdenumen_US
dc.subjectMolybdenum carbideen_US
dc.subjectMolybdenum oxideen_US
dc.subjectReductionen_US
dc.titleStudies on influence of hydrogen and carbon monoxide concentration on reduction progression behavior of molybdenum oxide catalysten_US
dc.typeArticleen_US
dspace.entity.typePublication

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