Synthesis of a SiO2 nanofibre confined Ni catalyst by electrospinning for the CO2 reforming of methane

Abstract

A silica (SiO₂) nanofibre confined nickel (Ni) catalyst was successfully synthesized by the electrospinning technique and was then systematically characterized with thermogravimetric/differential thermal analysis (TG/DTA), X-ray photoelectron spectroscopy (XPS), N₂ sorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution-transmission electron microscopy (HR-TEM), temperature-programmed oxidation (O₂-TPO), temperature-programmed reduction (H₂-TPR) and temperature-programmed desorption (CO₂-TPD) measurements. In the electrospinning synthesized Ni/SiO₂ catalyst, most of the Ni nanoparticles were confined inside SiO₂ nanofibers with an average particle size of 8.1 nm. Compared with the Ni/SiO₂ catalyst conventionally prepared via the incipient impregnation method using commercial SiO₂ powder as the support, the electrospun Ni/SiO₂ catalyst exhibited improved metal dispersion and enhanced metal-support interaction, leading to slightly higher activity and much better stability in the carbon dioxide (CO₂) reforming of methane. Carbon deposition, rather than metal sintering, is identified as the main cause for the deactivation of the Ni/SiO₂ catalyst under current conditions. The present work demonstrates that electrospinning is a potential technique for the fabrication of nanoconfined catalysts with superior catalytic performance and macro-scale handling properties.