ABSTRACT
Zudina L.V. Doped Fe2+, Co2+, NH4+ products of electrocrystallization of the Mn (IV) system from fluorine-containing electrolytes: composition - structure –properties. – Qualifying scientific work on the rights of the manuscript.The dissertation on competition of a scientific degree of the candidate of chemical sciences (doctor of philosophy) on a specialty 102 "Chemistry". – National Aviation
University, Specialized Academic Council of the National Aviation University of the Ministry of Education and Science of Ukraine. – Kyiv, 2021. – 202 p.
The triad composition - structure - functional property of manganese(IV) oxides doped with M(I, II) charging cations in the composition of the fluoride electrolyte of electrocrystallization is considered in the work. System of cations M(I) = NH4+; M(II) = Co2 +, Fe2 + was investigated to screen the electrocatalytic activity of electrocrystallization products in the oxygen reduction reaction in 0.3M KOH. The
doping-induced combination of phase states and additional structural defects affected the functionality. It was found that the ammonium cation is a template of the golandite phase component in the presence of M(II), and Co2+, Fe2+ / 3+ are capable of isomorphic
heterovalent substitution in the structure of ramsdellite. The CVA method showed the presence of an additional slow oxidation process, probably solid-phase, which determines the path of topochemical transformation into the golandite phase in the presence of the NH4+
cation. The oxides are characterized by SEM, XRD, FTIR, EPR, Mossbauer spectroscopy, potentiometric titration. Some aspects of the kinetics of electrocatalytic reduction and oxygen release on the investigated doped composite oxide electrocatalysts have been established. Including, exchange currents, overvoltage, etc. The correlations of functionality with the content of dopant ions, the 4 number of surface OH- -groups, the content of cationic vacancies, structural ingrowth defects were studied.
Key words: manganese(IV) oxide materials, electrolytic doping, anodic electrodeposition, electrocatalyst, oxygen reduction reaction, oxygen evolution reaction.
