ausblenden:
Schlagwörter:
Calcination, Electronic structure, Glass membrane electrodes, Iron compounds, Oxygen, Particle size, Potassium hydroxide, Precious metals, Ruthenium compounds, Strontium compounds, X ray absorption spectroscopy, X rays, Calcination temperature, Catalytic performance, Glassy carbon electrodes, Intrinsic activities, Metal-oxygen bonds, Preparation conditions, Proof of concept, Soft x-ray absorption spectroscopies, Perovskite
Zusammenfassung:
We report a facile and universal strategy with simultaneous modulation of intrinsic activity and active site numbers to optimize the catalytic performance of perovskites via controlling calcination temperature. As a proof-of-concept, the optimized SCF-800 perovskite (SrCo0.5Fe0.5O3-δ prepared with a calcination temperature of 800 °C) shows prominent OER activity (e.g., 327 mV at 10 mA cm-2 on a glassy carbon electrode in 0.1 M KOH), outperforming the benchmark noble-metal RuO2 and ranking the highest among perovskite-based catalysts reported to date. Experimental results reveal that the reduced particle size (increased surface area) due to a lower calcination temperature provides more active sites, and that the favorable electronic structure with high covalency of metal-oxygen bonds, as demonstrated by advanced soft X-ray absorption spectroscopy (sXAS), contributes to the intrinsic activity enhancement. This work provides a new and facile way for improving the catalytic performance via only regulating preparation conditions. This journal is © The Royal Society of Chemistry.
