Structural Properties of Thermally Activated Mixed Oxides

1 Structural Properties of Thermally Activated Mixed Oxides 

Alter thermal activation the layered structure of LDHs diminishes leading to the XRD reflections characteristic for the mixed oxides derived from thermal decomposition of LDHs [31, 37]. The structure of mixed oxides is defined as a regular, dense-packed, cubic, NaCl-type oxygen lattice, in which the metal atoms are octahedral oriented and oxygen ions are centered on the surface. Many authors defined these materials as mixed oxides type non-stoichiometric spinel or solid solutions of mixed oxides [2, 9, 38]. 

These oxides have a disordered structure with excess divalent cations in comparison with the amount of stoichiometric spinels present [1]. The main parameter for the crystal lattice, a  

Due to the reduced cation mobility in the 3D structure, the mixed oxides after thermal treatment have higher resistance compared to the synthesized LDHs that have a two-dimensional layered structure. Mixed oxides formed by thermal decomposition of LDH have greater stability than the mixed oxides formed by some other method [31]. 

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