Millisecond Engineering of Asymmetric Pt-Ov-Ce Interfaces via Hydrogen-Quenched Flame Spray Pyrolysis for...

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 O₂. 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.