Catalytic decomposition of methane over Ni/SiO2: influence of Cu addition

Abstract

The influence of Cu addition to Ni/SiO2 catalysts was studied in the catalytic decomposition of methane. Samples were prepared by impregnation and characterized by SBET, TPR, TPO, XRD and Raman spectroscopy. The activity tests were performed at temperatures ranging from 500 to 700 °C in a fixed bed reactor with in-line gas chromatography analysis. The presence of copper had an effect on the SBET of calcined samples, improving the dispersion and decreasing the reduction temperature of NiO particles. The addition of small amounts of copper facilitates the activation of NiO with methane and allows obtaining small crystallites of Ni°, which prevents the catalyst deactivation by sintering in temperatures above 500 °C. The characterization of carbon deposited on Cu-containing samples indicated the formation of multi-walled carbon nanotubes. The sample containing 1 wt% of Cu has the best performance for the production of hydrogen from methane decomposition.