Performance Enhancement in Pt–CeO₂@SiO₂ Core–Sheath Nanofibers in the Dehydrogenation of Cycloalkanes and Alkanes

Preventing the agglomeration and sintering of catalytically active platinum nanoparticles under reaction conditions is crucial for achieving enhanced catalytic performance, particularly in dehydrogenation processes. This work aims to design a core–sheath structure to protect Pt nanoparticles from agglomeration on a substrate such as ceria (CeO₂) and study the performance and stability of Pt nanoparticles under sheath protection. An electrospinning technique was employed to fabricate CeO₂ nanofibers (NFs), followed by impregnating Pt and introducing a silica (SiO₂) sheath layer to obtain Pt–CeO₂@SiO₂ core–sheath NFs. The structural, morphological, and physical properties of the resulting materials were evaluated by using X-ray diffraction (XRD), etching depth-profile X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-angle annular dark-field high-resolution scanning transmission electron microscopy (HAADF-STEM). The in situ XRD measurement followed by the Rietveld refinement showed the protective effect of the sheath layer against the agglomeration of Pt nanoparticles in Pt–CeO₂@SiO₂ materials. In the catalytic cyclohexane dehydrogenation (CDH) reaction, Pt–CeO₂@SiO₂ materials show a 4-fold increase in benzene yield compared to the Pt–CeO₂ structure without the sheath layer, with both catalysts exhibiting full selectivity for benzene.