Oleylamine-modified impregnation method for the preparation of a highly efficient Ni/SiO2 nanocatalyst active in the partial oxidation of methane to synthesis gas

Abstract

In this research, a novel modified wet impregnation method has been successfully developed to synthesize 5% Ni/SiO2 nanocatalyst with high catalytic activity and stability for the partial oxidation of methane. Oleylamine was used as a capping agent in the impregnation solution to improve Ni dispersion and interaction with silica surfaces. The product was analyzed and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, N2 physisorption measurement and transmission electron microscopy (TEM) and temperature- -programmed H2 reduction (H2-TPR). Partial oxidation of methane over the modified catalyst was performed in a continues-flow fixed-bed reactor under atmospheric pressure at 700?C. The modified catalyst showed 91% CH4 conversion, 86% H2 yield and 95% CO selectivity, and these results almost remained constant within 5 h reaction on stream. The excellent catalytic performance of the catalyst was reasonably attributed to the small and uniform distribution of Ni nanoparticles on the support, and structural characterization confirmed this conclusion.