Characterization of MgAl2O4 Precursor Powders Prepared by Aqueous Route

MgAl 2 O 4 spinel precursors have been prepared by two different aqueous synthesis routes: spray drying and citrate complexing. The spinel precursors exhibit different morphology and crystallization behavior. 27 Al high‐resolution magic‐angle spinning (MAS), multiple quantum MAS, and 27 Al‐{ 1 H} rational echo double resonance (REDOR) nuclear magnetic resonance experiments, show that the spinel precursors have different aluminum local structures. 27 Al‐{ 1 H} REDOR experiments detect Al IV ‐ and Al V ‐bearing proton‐free domains, possibly stabilized by residual carbonates, characteristic of the complexed precursor.