Carbon-resistant NiO-Y2O3-nanostructured catalysts derived from double-layered hydroxides for dry reforming of methane

Abstract

Yttrium promoted Ni/Mg/Al double-layered hydroxides were prepared through co-precipitation method and calcined at 550 °C for 5 h in order to obtain nanostructured mixed oxides. The catalysts were tested in dry reforming of methane (DRM) at 700 °C for 5 h, and characterized by X-ray diffraction, N2 adsorption-desorption, X-ray fluorescence, temperature programmed reduction in H2, temperature programmed desorption of CO2, thermogravimetric analysis, Raman spectroscopy, high-resolution transmission electron microscopy, and EDS elemental mapping carried out through transmission electron microscopy. It was found that with the increasing Y content the reducibility of Ni species and total basicity increased. Yttrium promotion with assumed 3.0 and 4.0 wt.% resulted in higher CH4 and CO2 conversions and H2/CO molar ratio as compared to unmodified catalyst. However, the samples suffered from the significant amount of carbon deposits. The best catalytic stability was found for NiY8-DLH (presumed Y of 8.0 wt.%), being highly resistant to coke formation in DRM.