(511f) Solution Combustion Synthesis of Nanostructured Cobalt Oxide for Sodium Borohydride Hydrolysis

Cobalt oxide and LiCoO₂ have recently been explored as catalysts for the hydrolysis of sodium borohydride and ammonia borane with promising results.  In several reports the hydrogen generation rate may meet that of typical, more expensive, noble metal catalysts such as Ru, Rh and Pt. However, the synthesis of such materials has generally been from decomposition of nitrates, acetates and mixtures thereof and can be quite slow (hours). This work reports the solution combustion synthesis of nanostructured cobalt oxide catalyst powder from cobalt nitrate-glycine solutions. The performance characterization of the catalyst for hydrolysis of sodium borohydride is compared to commercial Co and Co₃O₄ nanopowders.  Solution combustion synthesis is a cost effective, fast (minutes), reproducible method to synthesize powders with high purity (98-99%) and surface areas comparable to commercially available Co₃O₄ nanopowders (26-32 m²/g).  While X-ray diffraction analysis showed that the synthesized powders were not highly crystalline, the hydrogen generation rate, at 5 wt.% catalyst loading, was double that of commercial Co₃O₄ and Co nanopowders. Catalyst durability/reutilization will be discussed in detail.