Oxidative Dehydrogenation of Butenes over Co9Fe3Bi1Mo12O51@ZnFe2O4 Catalyst: Effect of Carbon Layer

 

    1,3-Butadiene, a major feedstock for synthetic rubber, can be obtained from two processes. One is the cracking and separation of light component in petroleum. Another is the oxidative dehydrogenation (ODH) of butenes. ZnFe₂O₄ and Co₉Fe₃Bi₁Mo₁₂O₅₁ are deemed as effective catalysts for the latter one, among which Co₉Fe₃Bi₁Mo₁₂O₅₁ exhibits higher reactivity in ODH of 1-butene while ZnFe₂O₄ in ODH of 2-butene. A synergistic effect by packing above two catalysts with certain sequence was achieved and it can improve the total yield of 1,3-butadiene from mixed-butenes. In this regard, to fabricate these two catalysts into one with ordered structure can be expected to be more efficient in ODH of butenes. In this work, a core-shell structured catalyst (referred as Co₉Fe₃Bi₁Mo₁₂O₅₁ @C@ ZnFe₂O₄) were successfully synthesized and investigated in ODH reaction, as shown in the figure below. Carbon material was employed as intermediate in order to enlarge the specific surface area of exterior metal oxide. The results demonstrate that the yield of 1-butene over Co₉Fe₃Bi₁Mo₁₂O₅₁ increase from 73% to 78% with one layer carbon coating, while that of over Co₉Fe₃Bi₁Mo₁₂O₅₁ @C@ ZnFe₂O₄ from 70% to 72% comparing with ZnFe₂O₄. With carbon intermediate involved, the better catalytic performance can be obtained and the synergistic effect was also proved with mixed-butenes.

* Corresponding author. Tel.: +86 571 8795 2728, Fax: +86 571 8795 1227

E-mail address: fqchen@zju.edu.cn (F.Q. Chen)