Imidazolium ionic Liquid-Regulated Sub-5-nm Pt(1 1 1) with a stable configuration anchored on hollow carbon nanoshells for efficient oxygen reduction

Abstract Here, N-doped hollow carbon sphere (NHCS)-supported (1 1 1)-plane-engineered sub-5-nm Pt (Pt-NHCS) catalysts regulated precisely by imidazolium ionic liquids were synthesized successfully and used to catalyze oxygen reduction. The (1 1 1)-plane engineered Pt nanocrystals with a diameter of 4.5 ± 0.5 nm were homogeneously deposited on the 3-dimensional spherical nanoshells. The resulting Pt nanocrystals anchored on the carbon skeleton exhibit a stable configuration in both alkaline and acid electrolytes with the help of imidazolium cations and pyrolysis. Among all as-prepared catalysts, the optimized Pt-NHCS shows remarkable long-term durability. Specifically, Pt-NHCS maintains 95.3% of the original current density after 10,000 potential cycles, while Pt/C benchmarks exhibit a retention of 78.5%. Accelerated durability test results indicate that Pt-NHCS exhibits a high efficiency of 96 % in comparison with initial current density, while a value of 86% for Pt/C. Density functional theory calculations demonstrate that reactive Pt(1 1 1) planes with well-defined Schottky defects and vacancies adsorb and activate oxygen molecule rapidly while desorbing the reaction intermediates.