Structural, surface, and catalytic properties of bismuth molybdovanadates containing foreign atoms: II. Propene oxidation on iron-containing bismuth molybdovanadate catalysts

Abstract

The selective oxidation of propene to acrolein has been studied on iron-containing bismuth molybdovanadates with the scheelite structure and general formula Bi 1 − x 3 x 3 − y Me y( V 1 − x Mo x − y Fe y) O 4, where Me = Fe or Bi , = cation vacancy, with x = 0.45 and 0.60 and 0 ⩽ y ⩽ x 3 , using the pulse technique in the temperature range 573–673 K. Total conversion, rate constant, and selectivity were found to depend on catalyst composition, in particular cation vacancy concentration, content, and coordination symmetry of the iron ions. The results, discussed in terms of compositional parameter y and surface geometry of BiO and MoO species, confirm the importance of the cation vacancies in the selective oxidation process and suggest a role of the eight-coordinated cations in the allyl formation.