Probing the Efficiency of 114 Cobaltite CaBaCo ₄ O ₇ for the Electrochemical Oxygen Evolution Reaction

Electrochemical technologies such as hydrogen evolution, fuel cells, and metal–air batteries demand highly efficient and durable oxygen evolution reaction (OER) electrocatalysts. Despite significant progress, the development of catalysts that combine high activity with long-term stability remains a major challenge. One of the decisive key factors in the efficiency of the OER is the optimal binding of the reaction intermediates with the electrocatalyst surface. The ternary metal compositions have emerged as promising candidates to achieve this balance and to enhance this optimal binding. In the present work, we report for the first time 114-type stoichiometric oxide CaBaCo4O7 as an electrocatalyst for the OER. CaBaCo4O7 shows a low OER potential with an observed overpotential of 0.34 V. These findings position CaBaCo4O7 as a promising and cost-effective alternative for next-generation OER catalysts.