Oxidative Dehydrogenation of 1-Butene over Lanthanum Strontium Iron Perovskite Oxides

Abstract

The catalytic activity of oxidative dehydrogenation of 1-butene (320°C) over two phase-mixed perovskite oxides of La_1-xSr_xFeO₃ (0≤X≤1.0) and SrFeO_3-y, was investigated in connection with the variation of SrFeO3-y crystal structure. The catalytic activity increased with Sr²⁺ substitution. A solid-solution was formed up to x =O.136 but SrFeO_3-y, was present above as a second phase. La_1-xSrxFeOO_3-y phase was active for oxidative dehydrogenation and isomerization of 1-butene. SrFeO_3-y, present as the second phase is readily reduced by 1-butene and undergoes an incomplete structural change to the more oxygen deficient perovskite oxide (SrFe_0.25) by generating CO₂ gas. This change in the structure of SrFeO_3-y, enhanced both the isomerization to 2-butenes and its complete oxidation by O₂ from gas phase.