Interfacial Ionic Liquid Conjugation: Unlocking Highly Active PtNi Aerogel Electrocatalysts for Oxygen Reduction

Abstract

Improving the oxygen reduction reaction (ORR) kinetics on Pt-based catalysts is pivotal for the practical deployment of fuel cells and metal–air batteries, yet achieving precise modulation of the surface electronic structure and local reaction microenvironment of Pt remains challenging. Herein, PtNi aerogels are employed as a model platform to demonstrate that ionic liquid (IL) modification can construct a conjugated interfacial system that effectively regulates the electronic structure of surface Pt sites. The resulting IL-conjugated PtNi aerogels (IL/PtNi aerogels) exhibit a remarkable mass activity of 2.12 A mgPt–1, representing 4.8- and 17.6-fold enhancements compared with pristine PtNi aerogels and commercial Pt/C, respectively. Combined experimental analyses and density functional theory (DFT) calculations reveal that the enhanced catalytic activity originates from IL-mediated electronic coupling at the Pt interface, which optimizes the adsorption energetics of oxygenated intermediates and accelerates ORR kinetics. This work establishes an effective interfacial conjugation strategy for tuning the electronic structure of Pt catalysts and provides new insights into the rational design of high-performance electrocatalysts for sustainable energy technologies.