TY - JOUR
T1 - Support effects on structure and activity of molybdenum oxide catalysts for the oxidative dehydrogenation of ethane
AU - Tsilomelekis, George
AU - Christodoulakis, Antonios
AU - Boghosian, Soghomon
N1 - Funding Information:
The authors are grateful to P. Tsourapas for undertaking a part of the experimental work and to Angeliki Lemonidou and Eleni Heracleous (University of Thessaloniki) for providing the MoAl catalyst samples. Financial support from the European Social Fund (ESF), Operational Program for Educational and Vocational Training II (EPEAEK II), and particularly the HRAKLEITOS program is gratefully acknowledged.
PY - 2007/9/30
Y1 - 2007/9/30
N2 - The structural and catalytic properties of MoO3 catalysts supported on ZrO2, Al2O3, TiO2 and SiO2 with Mo surface densities, ns, in the range of 0.5-18.5 Mo/nm2 were studied for the oxidative dehydrogenation (ODH) of ethane by in situ Raman spectroscopy and catalytic activity measurements at temperatures of 400-540 °C. The molecular structure of the dispersed surface species evolves from isolated monomolybdates (MoO4 and MoO5, depending on the support) at low loadings to associated MoOx units in polymolybdate chains at high loadings and ultimately to bulk crystalline phases for loadings exceeding the monolayer coverage of the supports used. The nature of the oxide support material and of the Mo-O-support bond has a significant influence on the catalytic behaviour of the molybdena catalysts with monolayer coverage. The dependence of reactivity on the support follows the order ZrO2 > Al2O3 > TiO2 > SiO2. The oxygen site involved in the anchoring Mo-O-support is of relevance for the catalytic activity.
AB - The structural and catalytic properties of MoO3 catalysts supported on ZrO2, Al2O3, TiO2 and SiO2 with Mo surface densities, ns, in the range of 0.5-18.5 Mo/nm2 were studied for the oxidative dehydrogenation (ODH) of ethane by in situ Raman spectroscopy and catalytic activity measurements at temperatures of 400-540 °C. The molecular structure of the dispersed surface species evolves from isolated monomolybdates (MoO4 and MoO5, depending on the support) at low loadings to associated MoOx units in polymolybdate chains at high loadings and ultimately to bulk crystalline phases for loadings exceeding the monolayer coverage of the supports used. The nature of the oxide support material and of the Mo-O-support bond has a significant influence on the catalytic behaviour of the molybdena catalysts with monolayer coverage. The dependence of reactivity on the support follows the order ZrO2 > Al2O3 > TiO2 > SiO2. The oxygen site involved in the anchoring Mo-O-support is of relevance for the catalytic activity.
KW - Anchoring bonds
KW - Ethane ODH
KW - In situ Raman spectra
KW - Molecular structure
KW - Molybdena active sites
KW - Support cation elecronegativity
KW - Support effect
KW - Supported molybdena catalysts
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U2 - 10.1016/j.cattod.2007.03.026
DO - 10.1016/j.cattod.2007.03.026
M3 - Article
AN - SCOPUS:34548133022
SN - 0920-5861
VL - 127
SP - 139
EP - 147
JO - Catalysis Today
JF - Catalysis Today
IS - 1-4
ER -