Electrocatalytic activity of calcined manganese ferrite solid nanospheres in the oxygen reduction reaction Flores Lasluisa, J. X. Moreno Castilla, Carlos Manganese ferrite Manganese oxidation states Carbon black Electrocatalyst Oxygen reduction reaction Authors from the Universidad de Alicante acknowledge to the Ministerio de Ciencia e Innovacion (PID2019-105923RB-I00) for financial support. J.X.F.-L. gratefully acknowledges (MINECO for the financial support through an FPI contract (BES-2017-081598) . D.S.-T. thanks MICINN for the "Juan de la Cierva" contract (IJCI-2016-27636) . M.V.L.-R. and C.M.-C. acknowledge to Junta de Andalucia, projects RNM366 and RNM172, respectively. In this study, we synthesized MnFe2O4 solid nanospheres (MSN) calcined at different temperatures (200–500 ◦C) and MSN-based materials mixed with carbon black, for their use as electrocatalysts in the oxygen reduction reaction (ORR) in alkaline medium (0.1 M KOH). It was demonstrated that the calcination temperature of MSN material determined its chemical surface composition and microstructure and it had an important effect on the electrocatalytic properties for ORR, which in turn was reflected in the performance of MSN/CB-based electrocatalysts. The study revealed that the presence of Mn species plays a key role in the ORR activity. Among tested, MSN200/CB and MSN350/CB exhibited the best electrochemical performances together with outstanding stability. 2021-11-02T07:28:31Z 2021-11-02T07:28:31Z 2021-09-23 journal article J.X. Flores-Lasluisa... [et al.]. Electrocatalytic activity of calcined manganese ferrite solid nanospheres in the oxygen reduction reaction, Environmental Research, Volume 204, Part B, 2022, 112126, ISSN 0013-9351, [https://doi.org/10.1016/j.envres.2021.112126] http://hdl.handle.net/10481/71199 10.1016/j.envres.2021.112126 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ open access Atribución-NoComercial-SinDerivadas 3.0 España Elsevier