Electrostatic Self-Assembly of the Composite La0.7Sr0.3MnO3@Ce0.75Zr0.25O2 as Electrocatalyst for the Oxygen Reduction Reaction in Aluminum-Air Batteries

摘要

La1-xSrxMnO3 (LSM) has been proposed as one of the best oxygen reduction reaction catalysts (ORRCs) to substitute noble metals. It is well known that an improvement of the oxygen-adsorption capacity is beneficial to the catalytic activity of LSM perovskites. Herein, the composite material La0.7Sr0.3MnO3@Ce0.75Zr0.25O2 (LSM@CZ) has been synthesized by a facile electrostatic self-assembly method in a two-step strategy. The CZ nanoparticles are well distributed on the surface of the LSM material. The LSM-4CZ composite catalyst exhibits a good catalytic activity in alkaline solution. The onset potential, half-wave potential, and electron transfer number of the LSM-4CZ composite catalyst are 0.898 V, 0.695 V, and 4, respectively. The LSM-4CZ composite catalyst has a good durability with current retention of 93.9% after 80000s and it exhibits a much better stability than Pt/C, the retention of which is 83.5%. If we used LSM-CZ as the ORRC, the maximum power density of the Al-air battery reached 242.9 mWcm(-2), which is approximately 40% higher than that of the battery with LSM (177.3 mWcm(-2)). This indicates that the LSM@CZ composite material is a promising cathodic electrocatalyst for metal-air batteries.