Ceria-promoted Ni/SBA-15 catalysts for ethanol steam reforming with enhanced activity and resistance to deactivation

Abstract

This paper describes the synthesis of CeO2-promoted Ni/SBA-15 catalysts (denoted as CeNi/SBA-15) via a surfactant-assisted iso-volumetric impregnation method and their application in ethanol steam reforming. Various techniques including N2 adsorption–desorption, X-ray diffraction, H2 temperature-programmed reduction, temperature-programmed oxidation, transmission electron microscopy and thermogravimetric analysis were employed to characterize the prepared and spent catalysts. The results showed that the incorporation of CeO2 could effectively control the particle size of Ni via strong metal-support interaction and promote the homogeneous distribution of Ni and Ce to achieve large Ni–CeO2 interface. Consequently, the CeNi/SBA-15 catalysts exhibited superior activity with respect to the reference Ni/SBA-15 catalyst without ceria addition. The effect of ceria loading on the properties of the catalysts was also investigated, and the catalyst with Ce/Ni atomic ratio of 1 was the optimized composition owing to its strong metal-support interaction and high nickel active surface area. The ceria-promoted catalysts showed enhanced long-term stability in ethanol steam reforming. The strong interaction between Ni and CeO2, as well as the confinement of SBA-15 support restricted the nickel particle growth under harsh reaction conditions. Additionally, the ceria promoter contributed to suppressing coke deposition effectively, which led to the enhanced coking-resistance as observed on CeNi/SBA-15 catalysts.