A single site ruthenium catalyst for robust soot oxidation without platinum or palladium.

Li, Yuanfeng; Qin, Tian; Wei, Yuechang; Xiong, Jing; Zhang, Peng; Lai, Kezhen; Chi, Hongjie; Liu, Xi et al. · Nat Commun · 2023

basic_science · Level V

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Abstract

The quest for efficient non-Pt/Pd catalysts has proved to be a formidable challenge for auto-exhaust purification. Herein, we present an approach to construct a robust catalyst by embedding single-atom Ru sites onto the surface of CeO<sub>2</sub> through a gas bubbling-assisted membrane deposition method. The formed single-atom Ru sites, which occupy surface lattice sites of CeO<sub>2</sub>, can improve activation efficiency for NO and O<sub>2</sub>. Remarkably, the Ru<sub>1</sub>/CeO<sub>2</sub> catalyst exhibits exceptional catalytic performance and stability during auto-exhaust carbon particle oxidation (soot), rivaling commercial Pt-based catalysts. The turnover frequency (0.218 h<sup>-1</sup>) is a nine-fold increase relative to the Ru nanoparticle catalyst. We further show that the strong interfacial charge transfer within the atomically dispersed Ru active site greatly enhances the rate-determining step of NO oxidation, resulting in a substantial reduction of the apparent activation energy during soot oxidation. The single-atom Ru catalyst represents a step toward reducing dependence on Pt/Pd-based catalysts.