In:
EES Catalysis, Royal Society of Chemistry (RSC), Vol. 1, No. 5 ( 2023), p. 730-741
Kurzfassung:
Herein, we demonstrate that introduction of secondary metals into the promising manganese–antimony oxide acidic water oxidation catalysts endows the resulting materials with superior activity and stability in operation. Using a simple solution-based method, we synthesised multi-metallic manganese antimonates [MnM + Sb]O x with M = Ru, Co, Pb and Cr. All of the secondary metals examined notably increase the initial activity of the mixed oxides towards the oxygen evolution reaction (OER) in 0.5 M H 2 SO 4 at ambient temperature, though [MnCr + Sb]O x and [MnRu + Sb]O x were found to be less stable. In contrast, [MnCo + Sb]O x , [MnPb + Sb]O x and [MnCoPb + Sb]O x maintained high stability and improved the overpotential required to achieve the water oxidation rate of 10 mA cm −2 by 0.040 ± 0.014, 0.08 ± 0.03 and 0.050 ± 0.014 V with respect to the parent [Mn + Sb]O x catalyst, respectively. Similar improvements in performance were found after tests at elevated temperature of 60 ± 1 °C. The [MnPb + Sb]O x system exhibits one of the highest activities for the OER at low pH reported for the noble-metal free catalysts so far, viz . 10 mA cm −2 OER at 0.60 ± 0.03 V overpotential at 24 ± 2 °C with a flat electrode. We ascribe this improved performance to the stabilising effect of lead oxides on the catalytically active manganese sites, which is demonstrated herein by in situ spectroelectrochemical X-ray absorption analysis.
Materialart:
Online-Ressource
ISSN:
2753-801X
Sprache:
Englisch
Verlag:
Royal Society of Chemistry (RSC)
Publikationsdatum:
2023
ZDB Id:
3146060-4
