Syngas production from dry methane reforming over yttrium-promoted nickel-KIT-6 catalysts

Dry reforming of methane was studied over Ni,Y-promoted KIT-6 ordered mesoporous silicas, prepared by incipient impregnation (nickel content 12 wt%, yttrium content of 4 wt %, 8 wt% or 12 wt%). The catalysts were characterized by XRF, FT-IR, TGA/DSC-MS, N-2-adsorption, TEM, HRTEM, XRD and TPR-H-2. The promotion with 8 wt% Y (Y/Si = 0.05) resulted in the highest activity and H-2/CO molar ratio closer to the stoichiometric value at temperatures from 600 to 750 degrees C. The characterization results of the yttrium promoted materials showed higher reducibility of the bulk NiO, bigger Ni crystallite size after reduction and DRM test, and better dispersion of nickel in the channels of the KIT-6 support. Additionally, larger Ni particles were observed on the external surface of the support, which may be related to catalytic selectivity towards carbon forming reactions. Upon dry methane reforming the segregated phases of Ni-0, Y2O3, and possibly Y2Si2O7 were registered. No presence of a Ni,Y alloy was observed. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.