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AuthorHameed, Areeba
AuthorLogade, Khulood
AuthorAli, Naba
AuthorGhosh, Priya
AuthorShafath, Sadiya
AuthorSalim, Sumaiya
AuthorAshok, Anchu
AuthorKumar, Anand
AuthorSaad, Mohd Ali H Saleh
Available date2020-10-22T07:00:25Z
Publication Date2020
Publication NameQatar University Annual Research Forum & Exhibition 2020
CitationHameed A., Logade K., Ali N., Ghosh P., Shafath S., Salim S., Ashok A., Kumar A., Saad M.A.H.S., "Highly active bifunctional LaMO3 (M=Cr, Mn, Fe, Co, Ni) perovskites for oxygen reduction and oxygen evolution reaction in alkaline media", Qatar University Annual Research Forum and Exhibition (QUARFE 2020), Doha, 2020, https://doi.org/10.29117/quarfe.2020.0106
URIhttps://doi.org/10.29117/quarfe.2020.0106
URIhttp://hdl.handle.net/10576/16641
AbstractLanthanum based electrocatalytically active perovskites, LaMO3 (M=Cr, Mn, Fe, Co, Ni), were synthesized using a single step solution combustion synthesis technique. The perovskites showed exceptional performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline medium. Based on the experimental results and literature survey, it is suggested that the exceptional activity of Mn and Co based lanthanum perovskite catalyst could be due to the optimum stabilization of reaction intermediates involved in the rate-determining step (RDS) of ORR/OER. According to crystal field theory (CFT), the d-orbital of transition metals are affected by the octahedral arrangement of six negative charges around it. The d orbital degenerates by splitting into two high energy (eg) and three lower energy orbitals (t2g) while maintaining the same average energy level [1]. The rate-determining step in the ORR/OER reaction that based on the eg orbital filling of B site transition metal cations If the d-electrons are less, the valence state goes up and lowering the eg orbital filling that results in strong adsorption of oxygenated species on the B site (strong B-OH bond) [2]. This strong bonding limits the overall reaction rate by the slow desorption of OH and its derivatives during ORR/OER. Similarly, too high eg filling causes weak adsorption of oxygenated species that limits the reaction through the slow adsorption of reactants. Therefore, to enhance the activity of ORR/OER reaction it is required to balance the adsorption and desorption of the reactants and the intermediate respectively. The better way is to optimize the eg orbital filling to be nearly 1 (eg = 1).Based on the experimental results and literature survey, it is suggested that the exceptional activity of Mn and Co based lanthanum perovskite catalyst could be due to the optimum stabilization of reaction intermediates involved in the rate-determining step (RDS) of ORR and OER [3].
Languageen
PublisherQatar University Press
SubjectPerovskites; Combustion synthesis; Oxygen reduction reaction; Fuel cells.
TitleHighly active bifunctional LaMO3 (M=Cr, Mn, Fe, Co, Ni) perovskites for oxygen reduction and oxygen evolution reaction in alkaline media
TypePoster
dc.accessType Open Access


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