High thermodynamic stability of La-deficient rhombohedral form of lanthanum manganite phase as decisive factor in effective ketonization reaction of 1-butanol

The bimolecular ketonization of 1-butanol by lanthanum manganite perovskite of different La/Mn stoichiometry is reported. A quite high catalytic activity at relatively low temperature (∼320 °C) is found for La-deficient composition (La/Mn = 0.91). The property found is likely attributed to high concentration of the active centers (deep La-site deficiency of the catalyst's rhombohedral structure form) and to high concentration of the oxidant, i.e., Mn ions of comparatively high valence (VMn), present in fully occupied Mn-sublattice. All these factors, additionally reinforced by the highest temperature and VMn variation stability of the catalyst (∼1100 °C, 3.4 ≤ × ΔVMn ≤ 3.17), ensure its the highest catalytic activity among the other compositions available.

In the bimolecular reaction entitled, a high catalytic activity at exceptionally low temperature (∼320 °C) is found for La-site deficient composition (La/Mn = 0.91) of lanthanum manganite perovskite in its rhombohedral structure form. This property is likely attributed to high concentration of active centers (deep La deficiency) and to high concentration of the oxidant, i.e., Mn ions of comparatively high valence, present in fully occupied Mn-sublattice. In comparison with the samples of the other stoichiometry of this phase, both these factors permit for the highest stability and the highest oxidative ability.Figure optionsDownload as PowerPoint slide