Cheaper efficient catalysts made from earth abundant materials (not noble metals) are indispensible for extracting hydrogen from water, the essential precursor to all globally sustainable fuels. Attaining this goal and the reduction of CO 2 to liquid fuels are the enabling innovations needed to replace fossil fuels. We have synthesized different polymorphs of LiCoO 2 and compared their catalytic activity in water oxidation. Our results show that LiCoO 2 is active exclusively in the cubic "spinel-like" structure, while inactive as the layered phase, which is thermodynamically more stable. The related spinel LiMn 2O 4 is transformed from an inactive rock to a highly efficient water oxidation catalyst (λ-MnO 2) upon Li + removal. These materials contain cubical metal-oxo (M 4O 4) subunits (absent in the layered analog) that appear to be the key to catalytic activity. We shall describe the biological basis for the high activity of the M 4O 4-cubical topology and anode performance of various activated spinels in water oxidation.
ASJC Scopus subject areas
- Chemical Engineering(all)