One-pot fabrication of yolk-shell structured La0.9Sr0.1CoO3 perovskite microspheres with enhanced catalytic activities for oxygen reduction and evolution reactions

Efficient electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play a critical role in the performance of fuel cells and metal-air batteries. In this work, we report a one-pot fabrication pathway to prepare yolk-shell structured La0.9Sr0.1CoO3 perovskite microspheres as highly active electrocatalysts for the ORR. The shell number could be controlled by using different solvents. Compared with regular La0.9Sr0.1CoO3 particles, yolk-shell structured La0.9Sr0.1CoO3 oxides have larger specific surface area. Catalytic activities of the as-prepared catalysts for the ORR and OER in 0.1 M KOH media have been studied by using a rotating ring-disk electrode (RRDE) technique. RRDE results show that multi-shelled La0.9Sr0.1CoO3 exhibits better catalytic activity for the ORR and OER with durabilities superior to commercial Pt/C catalysts.