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

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 degrees C for 5 h, and characterized by X-ray diffraction, N-2 adsorption-desorption, X-ray fluorescence, temperature programmed reduction in H-2, 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 H-2/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.

Automated summary

Yttrium promotion in Ni/Mg/Al double-layered hydroxides leads to improved reducibility of Ni species and total basicity, resulting in higher CH4 and CO2 conversions in dry reforming of methane. However, this also leads to significant carbon deposits, with NiY8-DLH showing the best catalytic stability.