Mechanistic study on the activity of manganese oxide catalysts for oxygen reduction reaction in an aprotic electrolyte

Study on Electrolyte Stability and Oxygen Reduction Reaction Mechanisms in the Presence of Manganese Oxide Catalysts for Aprotic Lithium–Oxygen Batteries

“… Possible ORR mechanisms detectable by CV; chemical reactions that can be deduced from CV measurements are given in red; the electrochemical and chemical reactions detected, respectively, are indicated by the corresponding Tafel slope values; n* values are given as obtained for the different electrode materials from CV with a scan rate of 100 mV s −1 …”

“…CV investigations of the ORR mechanisms in the presence of various Mn x O y electrocatalysts recorded with a potential scan rate of 100 mV s −1 were published previously (for CV measurements recorded with ν =100 mV s −1 , see Figure S1 in the Supporting Information). Different catalyst properties, such as the Mn z+ oxidation state and particle diameters, were suggested to have a strong influence on the observed ORR processes …”

“…For GC and α‐Mn 2 O 3 /C values of n* ≈1 were obtained from the Nicholson–Shain relationship. The detection of a diffusion‐controlled ORR mechanism for GC in the complete scan rate range is shown in Figure a (grey squares), which is in good agreement with previous reports for a scan rate of 100 mV s −1 . The same ORR pathway (which results in the formation of LiO 2 and Li 2 O 2 , Reactions 1 a–d in Scheme ) can be observed for α‐Mn 2 O 3 /C in the complete range of scan rates (blue squares in Figure a).…”

“…The same ORR pathway (which results in the formation of LiO 2 and Li 2 O 2 , Reactions 1 a–d in Scheme ) can be observed for α‐Mn 2 O 3 /C in the complete range of scan rates (blue squares in Figure a). The fact that the diffusion control of the ORR mechanism does not change with the applied scan rate supports the assumption of the large impact of the electrode surface properties on the ORR mechanism . Here, the smooth GC surface and the large α‐Mn 2 O 3 particles provide a comparably low amount of active sites, where O 2 dissociation could take place (e.g., kinks and edges).…”

Facile synthesis of electrospinning Mn2O3-Fe2O3 loaded carbon fibers for electrocatalysis of hydrogen peroxide reduction and hydrazine oxidation

“…Manganese oxides, as highly efficient transition metal oxide catalysts, exhibit favorable electrochemical properties in oxygen reduction reaction [32,33]. However, there are still some problems in the application of manganese oxides to analyze small molecules, such as the narrow linear range and long response time of H 2 O 2 and N 2 H 4 detection [34,35].…”