Dependence of the oxygen reduction reaction at sol-gel derived Co-based catalysts on acidic solution pH and temperature

► The Co-pda-derived material (900 °C) is a better ORR catalyst than the Co-en-derived material (700 °C). ► The Co-pda-derived catalyst, the transfer coefficient (α) is ∼1 and no pH dependence of the ORR rate at pH < 2.6. ► A possible mechanism for the ORR at pH < and > 2.6 was presented. ► The ORR was examined as a function of solution temperature (12-62 °C). ► It was also found that the catalyst was unstable at solution temperatures above around 50 °C.