Fig. 6: OER catalytic mechanism analyses.
From: Electrocatalytic water oxidation with manganese phosphates
a, b In-situ XANES spectra for Mn K-edge of KMnPO4 and KMnPO4•H2O at potentials ascending from 1.00 to 1.80 V in 0.05 M PBS (pH=6.99) (The solution resistance is 138.7 ± 1.2 Ω). c, d The EXAFS oscillation functions of KMnPO4 and KMnPO4•H2O. e, f Mn K-edge EXAFS spectra for KMnPO4 and KMnPO4•H2O at different potentials. The Fourier transform (FT) spectra were not phase-corrected. g The coordination number changes of KMnPO4 and KMnPO4•H2O during OER. h, i DEMS signals of 36O2 (18O18O, mass/charge ratio (m/z) = 36), 34O2 (16O18O, m/z = 34), and 32O2 (16O16O, m/z = 32) from the gaseous products for KMnPO4 (h) and KMnPO4•H2O (i) catalysts in H218O aqueous PBS electrolyte during three times of cycles in the potential range of 0.90 to 2.10 V versus RHE at a scan rate of 5 mV•s−1 (The solution resistance is 138.7 ± 1.2 Ω). Proposed OER mechanisms for KMnPO4 (j) and KMnPO4•H2O (k) in neutral PBS solutions.
