Preparation, characterization, and catalytic activity of bismuth molybdate catalysts for the oxidative dehydrogenation of n-butene into 1,3-butadiene

Abstract

Three types of bismuth molybdate catalysts, α-Bi 2Mo 3O 12, β-Bi 2Mo 2O 9, and γ-Bi 2MoO 6, were prepared by a co-precipitation method for use in the oxidative dehydrogenation of n-butene. Unlike α-Bi 2Mo 3O 12 and γ-Bi 2MoO 6, it was found that β-Bi 2Mo 2O 9 was thermally unstable and decomposed into α-Bi 2Mo 3O 12 and γ-Bi 2MoO 6 at the reaction temperature of 420 °C. Therefore, β-Bi 2Mo 2O 9 could not serve as an efficient catalyst in the reaction. In the oxidative dehydrogenation of n-butene into 1,3-butadiene, γ-Bi 2MoO 6 showed a better catalytic performance than α-Bi 2Mo 3O 12. The different catalytic performance between α-Bi 2Mo 3O 12 and γ-Bi 2MoO 6 catalysts was elucidated by temperature-programmed reoxidation (TPRO) experiments. It was revealed that the enhanced catalytic performance of γ-Bi 2MoO 6 was attributed to the facile oxygen mobility of γ-Bi 2MoO 6.