Optimizing LaNiO3 surface structure for an efficient oxygen reduction reaction†

Perovskite oxides, with their flexible electronic structure and low cost, are highly attractive alternatives to noble metal catalysts for oxygen redox reactions (ORRs). Herein, we report LaNiO₃ perovskite as an efficient ORR catalyst, where oxygen vacancies and oxygen-containing functional groups work synergistically. LaNiO₃ was subjected to thermal shock in different media to introduce defects on the structural surface. Experimental results indicate that thermal shock in air creates oxygen vacancies on the catalyst surface, while thermal shock in aqueous solution increases the content of oxygen-containing functional groups (–OH) on the surface. The samples subjected to thermal shock exhibit superior ORR catalytic performance, with the limiting current density increasing from 4.2 mA cm⁻² to 5.4 mA cm⁻². This work provides a convenient and straightforward approach for constructing a series of materials enriched with surface defects.