Linear sweep voltammetry of manganate(VII), manganate(VI), and manganate(V) in alkaline media
1976; Elsevier BV; Volume: 21; Issue: 4 Linguagem: Inglês
10.1016/0013-4686(76)80015-1
ISSN1873-3859
Autores Tópico(s)Analytical Chemistry and Sensors
ResumoElectrochemical reactions were assigned to the voltammetric waves obtained in alkaline KMnO4 and K2MnO4 solutions. Plots of ip (AC°ν12)−1 and iapicp−1 νs log ν indicate that at slow potential scan rates in MnO−4 solutions ranging from 0·07 to 0·19 F in NaOH the first step in MnO−4 reduction is a l-electron reversible charge transfer with no coupled chemical reaction; at fast scan rates (⩾ V s−1 the process becomes quasi-reversible. The standard rate constant and the activation energy for the MnO−4/MnO2−4 charge transfer step were estimated. Plots of ip (AC°ν12)−1 and iapicp−1 νs log ν indicate that in 4·O F KOH and at potential scan rates between 0·005 and 2·V s−1 the reduction of MNO2−4 to MnO3−4 is a reversible charge transfer with no coupled chemical reaction. The diffusion coefficients of MnO−4 and MnO2−4 in alkaline solutions are reported.
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