1 research outputs found
Electrocatalysis of oxygen on bifunctional nickelâcobaltite spinel
7 Figures, 2 Tables.-- This article also appears in: Giornate dellâElettrochimica Italiana (GEI 2019).Transitionâmetalâbased materials are among the most active and durable catalysts for the effective electrocatalysis of oxygenârelated reactions. Herein, we present a study on bifunctional catalysts as air electrodes aimed at metalâair batteries based on nickel and cobalt spinel (NiCo2O4) supported on electrospun carbon nanofibers. The physicochemical features of these transitionâmetalâbased catalysts are essential for the understanding of their electrochemical activity. Results show that the major presence of oxidized Ni and Co species (Ni3+ and Co3+) produces higher activity for the oxygen evolution reaction (OER), whereas lower oxidation states of the metals (Ni2+, Co2+, Ni0 and Co0) together with the presence of Nâdoped carbon lead to enhanced oxygen reduction reaction (ORR) performance. This study highlights the importance of designing catalysts in terms of crystallographic structure and proper oxidation states of the elements for maximizing their performance.The research leading to these results has received funding from the âAccordo di Programma CNRâMiSE, Gruppo tematico Sistema Elettrico Nazionale e Progetto: Sistemi elettrochimici per lâ˛accumulo di energiaâ.Peer reviewe