The effects of Fe-doping on MnO₂: phase transitions, defect structures and its influence on electrical properties

Abstract

Phase transformation from initially α-MnO2 to R-MnO2 due to Fe-doping cause modification of interatomic distances affects to the electrical properties.

Micro-area investigation on electrochemical performance improvement with Co and Mn doping in PbO2 electrode materials

“…8d, one can observe the appearance of two signals at BE ¼ 642.64 eV and 654.04 eV, assignable to Mn 2p 3/2 and Mn 2p 1/2 , respectively, and the interval between the two peaks is 11.4 eV, which indicates that the oxidation state of Mn in the modied electrode is MnO 2 (ref. 45) because the binding energy in the gure is 645.21 eV, which is Pb 4p. Since the binding energy of the stronger Pb 4p peak, Pb 4p 3/2 is similar to that of the O 1s peak, the two peaks coincide and need to be tted.…”

Experimental correlation of Mn3+cation defects and electrocatalytic activity of α-MnO2– an X-ray photoelectron spectroscopy study

“…[77][78][79] However, besides being benecial for the stabilization of the tunnel structure, low-valent cations such as K + and Ag + occupying the tunnels oblige a-MnO 2 to adapt a lower oxidation state, i.e., from Mn 4+ to Mn 3+ , in order maintain charge neutrality. 75,[80][81][82][83][84] Ultimately, this can create manganese cation defects 19 along with oxygen vacancies, 80,84,85 which are considered to be catalytically active sites towards the ORR of MnO 2 . 86-91 2.1.3 Determination of Mn 3+ cation defect content.…”

“…, from Mn 4+ to Mn 3+ , in order maintain charge neutrality. 75,80–84 Ultimately, this can create manganese cation defects 19 along with oxygen vacancies, 80,84,85 which are considered to be catalytically active sites towards the ORR of MnO 2 . 86–91…”

Preparation of Cordierite Monolith Catalysts with the Coating of K-Modified Spinel MnCo2O4 Oxide and Their Catalytic Performances for Soot Combustion

“…The weak peak at 305 cm −1 may be related to the local crystal defect. The peak at 630 cm −1 can be assigned to symmetric stretch of Mn-O, which is perpendicular to the MnO 6 octahedral [50].…”