Controlled synthesis of highly active mesoporous Co ₃O ₄ polycrystals for low temperature CO oxidation

Polycrystalline mesoporous Co ₃O ₄ has been successfully fabricated using a simple but efficient controlled thermal decomposition approach and their catalytic activities for low temperature CO oxidation were evaluated. In such a synthesis, micrometer-sized polyhedral cobalt oxalate crystals were first prepared and used as precursor. Mesoporosity was then generated via the pyrolysis of the cobalt oxalate precursor and the resultant nano-sized Co ₃O ₄ crystallites connected together to form mesoporous structure within the original micrometer-sized particles. The as-prepared material by calcination at 300°C at a heating rate of 0.5°C/min possessed high surface area and showed extraordinarily high catalytic activity for low temperature CO oxidation, the full CO conversion can be achieved at as low as -70°C.