Syngas production via combined dry and steam reforming of methane over Ni-Ce/ZSM-5 catalyst

Abstract

Recently, dry reforming of methane (DRM) has drawn more attention because of its environmental benefit and effective utilization of energy. The main focus of this area relies on the aspect of improvement of catalytic properties of catalysts used in DRM. This paper aims to develop an ideal Ni-Ce/ZSM-5 catalyst and to find out the optimum reaction conditions to achieve the best performance. In order to overcome some shortcomings of DRM, steam was introduced in the reaction system to generate steam reforming of methane (SRM) simultaneously. Ni-Ce/ZSM-5 catalysts were prepared by the impregnation method, and different catalytic reaction conditions were investigated. It is found that these condition parameters affect the catalytic performance in varying degrees. By adjusting these parameters properly, the Ni-Ce/ZSM-5 catalyst possesses an outstanding ability to convert CH4 and CO2 into syngas with highest conversion up to 99% and 94%. In addition, it was proved that the catalyst prepared had great stability as well under the determined reaction conditions. During 40 h of long reaction, the catalyst maintained high activity and did not show obvious deactivation. The conversion of CH4 and CO2 remained 95% and 85% respectively and the ratio of syngas was close to 1. Moreover, the catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), specific surface area and pore size analysis, TG analysis and H2-TPR analysis. The result of the characterization clarified the structure and composition of the catalysts and gave a better explanation of the catalytic performance.