Ammoxidation of C2 hydrocarbons over Mo–zeolite catalysts prepared by solid-state ion exchange: Nature of molybdenum species - Archive ouverte HAL
Article Dans Une Revue Microporous and Mesoporous Materials Année : 2016

Ammoxidation of C2 hydrocarbons over Mo–zeolite catalysts prepared by solid-state ion exchange: Nature of molybdenum species

Résumé

Successful introduction of molybdenum (from MoCl3) into zeolites of different topologies was carried out using solid-state ion exchange. MOR like support extended the formation of Mo oxides due to its particular aperture/channel-shapes. However, BEA and MFI (ZSM-5) zeolites structures loaded small aggregates of Mo oxide. Exchanging MoCl3 with NH4+–BEA, H+–ZSM-5 (Si/Al = 15) and NH4+–ZSM-5 (Si/Al = 26) led to the consumption of Brönsted acid sites and silanol groups, while the lack of exchange sites in NH4+–MOR generated Mo–OH as revealed by DRIFTS and TPD of NH3. Polymeric Mo and MoO3 occupied the bulk of BEA and MOR issued solids. Nevertheless, NH4+–ZSM-5 (Si/Al = 26) support triggered the formation of dimeric species. For H+–ZSM-5 (Si/Al = 15) solid, monomeric species migrated throughout the channels of H+–ZSM-5, which condensed easily to form rather polymeric species. Small oxide crystallites and Mo moieties that weakly interact with NH4+–BEA and NH4+–ZSM-5 (Si/Al = 26) were easily reduced under hydrogen, while the negatively charged H+–ZSM-5 (Si/Al = 15) framework inhibited the reducibility.

Domaines

Catalyse
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Dates et versions

hal-01184902 , version 1 (18-08-2015)

Identifiants

Citer

Emna Mannei, Faouzi Ayari, Mourad Mhamdi, M Almohalla, A. Guerrero-Ruiz, et al.. Ammoxidation of C2 hydrocarbons over Mo–zeolite catalysts prepared by solid-state ion exchange: Nature of molybdenum species. Microporous and Mesoporous Materials, 2016, 219, pp.77-86. ⟨10.1016/j.micromeso.2015.07.036⟩. ⟨hal-01184902⟩
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