SYNTHESIS OF LOWER VALENT MOLYBDENUM OXIDES BY AN AMBIENT-TEMPERATUREREDUCTION OF AQUEOUS K2MOO4 BY KBH4

Reduction of aqueous K2MoO4 with aqueous KBH4 at ambient temperatures has been investigated systematically to obtain lower valent molybdenum oxides. Several lower valent oxides such as MoO2, Mo4O11, K0.26MoO3 ( red bronze), K0.30MoO3 (blue bronze), and K0.85Mo6O17 are formed durin g the reduction process; however, only MoO2 has been obtained as singl e-phase product. The nature of the product formed is strongly influenc ed by the reducing power of KBH4. The reducing power increases with de creasing pH or increasing concentration and volume of KBH4. The as-pre pared samples are amorphous as revealed by X-ray diffraction and trans mission electron microscopy. They crystallize sharply at around 350-50 0 degrees C as revealed by differential scanning calorimetry. Since th e products formed are amorphous in nature, they may become particularl y attractive for battery electrodes and catalysis.