Transition metal catalysts for porous carbon air-electrodes in neutral chloride electrolytes

Porous carbon air-electrodes activated by CoPC, FePHP, PdPC, PtPC and metal-free PC were studied in 2 mol dm^–3 NaCl electrolyte. The activity of heat-treated carbon activated by CoPC was compared to carbon activated byin situ formed Co oxide. All the results show that the main catalytic activity of the catalyst used comes from the central metal atom used, while the chelate or oxide structures serve predominantly to keep the metal in the stable form at the carbon surface. Metal-free phthalocyanine does not show any catalytic activity for oxygen reduction.