Morphology Dependent Catalytic Activity of Mn3O4for Complete Oxidation of Toluene and Carbon Monoxide

Manganese oxide catalysts having pure hausmanite (Mn3O4) phase but different morphologies were synthesized using three different facile methods namely precipitation method (MPM), reduction method (MRM) and solution combustion method (MSM). In spite of having the same phase, their catalytic activities showed strong dependence on their morphologies. Mn(3)O(4)synthesized using the reduction method had a 3D framework of interconnected hexagonal crystallites. Consequently, it showed the best activity among the synthesized and commercial Mn(3)O(4)catalysts both for carbon monoxide and toluene oxidation. This superior activity of MRM was correlated to its uniform pores and ability to desorb oxygen adspecies easily due to its morphology. The catalytic oxidation activity of this catalyst was not significantly affected at high space velocities. Thermal stability of the best performing catalyst was demonstrated through its stable cyclic performance, both for carbon monoxide and toluene oxidation.