The oxidation of isobutene was studied over various complex vanadium oxide catalysts. Mg2V2O7,Mg3V 208, and Mg3V208 are effective catalysts for isobutene formation at > 300°C. Cu2V2O6 and CaV2O6 catalysts showed intermediate activity, and BiVO4 and Ca7V4017 were slightly active. The active catalysts had relatively strong acidic sites, and H abstraction from the t-carbon of isobutene by acidic site was considered to be the initial and rate-determining step because a linear relationship was observed between the amount of acidic sites and the catalytic activity of the catalysts. The introduction of transition metals into the Mg sites of the Mg2V207 crystal lattice formed Mg1.8V2M0.207 (M = Mn, Cr, Fe, Co, Ni) catalysts. This substitution significantly promoted the catalytic activity without changing the selectivity for isobutene. Introduction of these transition metals increased the reactivity of lattice oxygen in Mg1.8V2catalysts. Decreased W/F increased the selectivity for isobutene approaching it to 100%, which suggests that the initial reaction is the oxidative dehydrogenation of isobutene without parallel COx formation.
|Number of pages
|Sekiyu Gakkaishi (Journal of the Japan Petroleum Institute)
|Published - Mar 2003
All Science Journal Classification (ASJC) codes
- Fuel Technology
- Energy Engineering and Power Technology