Silicalite-1 zeolite encapsulated Pt nanoparticles via ligand-protected in-situ construction for boosting auto-exhaust carbon particle oxidation
Year: 2025
Type: article
Abstract: The enhancement of activity and stability of noble metal-based catalysts for purification of auto-exhaust carbon particle (soot) oxidation remains a grand challenge under harsh reaction conditions. Herein, the encapsulated catalysts of platinum nanoparticles (NPs) confined in silicalite-1 zeolite (S-1) were prepared by the ligand-protected in-situ synthesis method. The Pt NPs (~ 4 nm) are located within the intersectional channels between the straight and the sinusoidal 10-ring channels of rigid S-1 zeolite, and well stabilize inside the S-1 via Pt-O-Si bonds. The Pt@S-1 catalyst (0.38 wt.% of Pt loading) exhibits excellent performance (T50 = 368 oC) compared with the conventional Pt/S-1 catalyst during soot oxidation. The Pt@S-1 catalyst displays high long-term catalytic stability after the hydrothermal aging at 800 oC for 10 h, and the deactivation rate of the Pt@S-1 catalyst is one-tenth that of the Pt/S-1 catalyst. In-situ DRIFTS and DFT calculations corroborated that the encapsulated Pt NPs in Pt@S-1 catalyst display a higher d-band center than the isolated Pt NPs, which enhances bonding strength for co-adsorption of NO and O2 molecules. The steric hindrance effect promotes the desorption of the critical intermediate of NO2, which is the key step to the NO2-assistant catalytic mechanism for soot oxidation. The ligand-protected in-situ confinement synthesis of metal nanoparticle catalysts not only ensures high activity and stability but also paves the way for the development of effective catalysts for soot oxidation in practical applications.
Source: Nano Research
Authors: Yuanfeng Li, Tian Qin, Hao Guo, Yuechang Wei, Yaxiao Ma, Linsheng Xu, Baolong Cui, Jing Xiong, Peng Zhang, Xi Liu, Liwei Chen, Yunpeng Liu, Jian Liu, Zhen Zhao
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,290
OpenAlex ID: W4409364644