Crystalline Calcium Ferrite Nanoparticles for Efficient Ethanol Electro-oxidation

Abstract Electrochemical ethanol oxidation (EOR) is a promising energy alternative, as it is inexpensive, easy to handle, less toxic, and produced from renewable biomass. The best-known materials for the EOR are noble-metal catalysts; however, their application is limited by poor durability and they are prone to CO poisoning. Therefore, developing cost-effective, CO-tolerant catalysts is crucial. In this work, nanocrystalline CaFe2O4 was synthesized via a simple sol–gel method. TEM analysis confirmed the formation of nanocrystalline CaFe2O4 particles. The synthesized CaFe2O4 nanoparticles display good electrocatalytic performance toward the ethanol oxidation reaction (EOR), which can be attributed to their nanoscale dimensions, enhanced surface accessibility, and favorable charge-transfer characteristics. The CaFe2O4 nanoparticles exhibited a promising oxidation peak current density of 1.01 mA cm–2 at a 1.50 V peak potential. They display a smaller Tafel slope of 112 mV dec–1 with high CO tolerance, making them a promising electrocatalyst to meet energy demand. The enhanced catalytic performance of the as-prepared nanoparticles is observed, as they exhibit a lower charge-transfer resistance, which facilitates ethanol oxidation, and they also demonstrate good durability for prolonged hours. The low-cost, simple spinel oxide CaFe2O4 can serve as an earth-abundant alternative to noble-metal catalysts for sustainable energy applications.