Core-Sheath Pt-CeO/Mesoporous SiO Electrospun Nanofibers as Catalysts for the Reverse Water Gas Shift Reaction.

One-dimensional (1D) core-sheath nanofibers, platinum (Pt)-loaded ceria (CeO) sheath on mesoporous silica (SiO) core were fabricated, characterized, and used as catalysts for the reverse water gas shift reaction (RWGS). CeO nanofibers (NFs) were first prepared by electrospinning (ES), and then Pt nanoparticles were loaded on the CeO NFs using two different deposition methods: wet impregnation and solvothermal. A mesoporous SiO sheath layer was then deposited by sol-gel process. The phase composition, structural, and morphological properties of synthesized materials were investigated by scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), nitrogen adsorption/desorption method, X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis, and CO temperature programmed desorption (CO-TPD). The results of these characterization techniques revealed that the core-sheath NFs with a core diameter between 100 and 300 nm and a sheath thickness of about 40-100 nm with a Pt loading of around 0.5 wt.% were successfully obtained. The impregnated catalyst, Pt-CeO NF@mesoporous SiO, showed the best catalytic performance with a CO conversion of 8.9% at 350 °C, as compared to the sample prepared by the Solvothermal method. More than 99% selectivity of CO was achieved for all core-sheath NF-catalysts.