CaCu3Ti4O12: A Bifunctional Perovskite Electrocatalyst for Oxygen Evolution and Reduction Reaction in Alkaline Medium

- A cost effective double perovskite CaCu3Ti4O12 have been synthesized using oxalate precursor method.
- CCTO electrocatalyst exhibit enhanced bifunctional electrocatalytic activities.
- CCTO electrocatalyst have lower overpotential and higher mass activity as compared to noble metal oxide and well-known perovskite catalysts.
- Electrochemical impedance spectroscopy investigations of oxygen reactions on perovskite surfaces.

Perovskite oxides are prominent materials as the bifunctional electrocatalysts for both oxygen reduction/evolution reactions (ORR/OER) for the electrochemical energy conversion and storage using regenerative fuel cells and rechargeable metal-air batteries. In this work, a quadruple perovskite CaCu3Ti4O12 has been synthesized oxalate precursor route. X-ray diffraction pattern shows phase purity of the synthesized electrocatalyst. The synthesized CCTO electrocatalyst have crystallite size of 26 nm. Electrochemical investigations reveal that CCTO exhibit efficient catalytic activity. More interestingly, an extremely high OER activity is observed for CCTO electrocatalysts which is found superior than similar class of perovskites. Additionally, CCTO shows efficient ORR activity with an onset potential of 0.83 V which is better than that of Pt/C catalyst (≈0.94 V). These results demonstrate the significant potential of CCTO perovskite as a bifunctional electrode material for alkaline fuel cells and metal-air batteries.

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