The ”In Situ” Research of the Synthesis of NiMoO4

The formation of the crystal structure of the NiMoO4 high temperature phase in the solid phase reaction NiO+u-M003+fiNiMo04at 600 C has been "in dtu" studied with the high temperature synchrotron technique. We have performed the measurements of the Extended X-ray Absorption Fine Structure (EXAFS) and the X-ray Absorption Near Edge Structure (XANES) at the Kedge of Ni atom in during the P-NiMo04 synthesis. The analysis of the XANES data and the Fourier transfonnants of the EXAFS data has led us to the conclusion that at the initial stage of synthesis the nearest oxygen surrounding of Ni atoms in the final production reaction has got an unique pometq that differs from the octahedral oxygen surrounding of Ni atoms in the both structures of NiO and $-NiMoOq. At the initial stage of the P-NiMo04 synthesis there is not the final product of the synthesis, but the formation of the P-NiMo04 crystal structure takes place essentially later, contrary to how it has been considered so far. We have concluded that at the original stage of the P-NiMoOa synthesis the some intermediate phase is formed that is characterized with the low concentration of nickel and the low symmetrical geometry for the nearest oxygen surrounding of Ni atoms .