A synergistic effect of α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts in the oxidative dehydrogenation of C4 raffinate-3 to 1,3-butadiene

α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts were prepared by a co-precipitation method for use in the oxidative dehydrogenation of C4 raffinate-3 to 1,3-butadiene. A series of mixed catalysts composed of α-Bi2Mo3O12 and γ-Bi2MoO6 were also prepared by a mechanical mixing method to investigate any synergistic effects of α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts in the oxidative dehydrogenation of C4 raffinate-3. The α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts were formed successfully, as confirmed by XRD, FT-IR, Raman spectroscopy, and ICP-AES analyses. The γ-Bi2MoO6 catalyst exhibited a better catalytic performance than the α-Bi2Mo3O12 catalyst due to its facile oxygen mobility. The conversion of n-butene and the yield for 1,3-butadine over the mixed catalysts showed volcano-shaped curves with respect to γ-Bi2MoO6 content due to the synergistic effect of the α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts. Among the mixed catalysts, the catalyst composed of 10 wt.% α-Bi2Mo3O12 and 90 wt.% γ-Bi2MoO6 showed the best catalytic performance. The γ-Bi2MoO6 catalyst retained a higher oxygen mobility than the α-Bi2Mo3O12 catalyst, while the α-Bi2Mo3O12 catalyst retained much more adsorption sites for n-butene than the γ-Bi2MoO6 catalyst. The synergistic effect of the α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts in the oxidative dehydrogenation of C4 raffinate-3 was due to a combination of the facile oxygen mobility of γ-Bi2MoO6 and the abundant adsorption sites of α-Bi2Mo3O12 for n-butene.

Graphical abstractA series of mixed catalysts composed of α-Bi2Mo3O12 and γ-Bi2MoO6 were prepared by a mechanical mixing method to investigate any synergistic effects of these two catalysts in the oxidative dehydrogenation of C4 raffinate-3 to 1,3-butadine. The conversion of n-butene and the yield for 1,3-butadine over the mixed catalysts showed volcano-shaped curves with respect to γ-Bi2MoO6 content due to the synergistic effect of the α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts. Figure optionsDownload full-size imageDownload as PowerPoint slide