Millisecond Engineering of Asymmetric Pt–Ov–Ce Interfaces via Hydrogen‐Quenched Flame Spray Pyrolysis for Anti‐Poisoning CO Oxidation

ABSTRACT Strong CO adsorption on platinum surfaces at low temperatures remains a critical bottleneck for the stability of emission control catalysts. While oxygen vacancy engineering can modulate metal–support interactions, conventional symmetric vacancies (Ce ^{3 +} –O _v –Ce ^{3 +} ) often suffer from poor structural durability and uniform charge distribution, which inherently limits their ability to dynamically regulate electronic states. Herein, a rapid one‐step strategy utilizing hydrogen‐quenching flame spray pyrolysis is developed to construct asymmetric Pt–Ov–Ce interfaces. Unlike symmetric defects, this engineered asymmetric configuration disrupts local charge symmetry, creating a built‐in electric field that acts as a directional electron channel to drive electron transfer from Pt to the ceria support. This spatial electronic reconstruction simultaneously reduces the electron density of Pt sites, significantly weakens the Pt–CO bond, thereby alleviating the poisoning of active sites and enriching interfacial vacancies, promoting the rapid activation of O ₂ . Consequently, the asymmetric catalyst achieves 90% CO conversion at 180°C, which is 46°C lower than conventional counterparts, and maintains exceptional stability with negligible activity loss over 1000 min. This study provides a fundamental understanding of local charge asymmetry in defect engineering and demonstrates the potential of millisecond flame quenching for designing highly poison‐resistant catalysts.