International Journal of Hydrogen Energy, Vol.39, No.21, 10927-10940, 2014
Y2O3-promoted NiO/SBA-15 catalysts highly active for CO2/CH4 reforming
A series of Y2O3-promoted NiO/SBA-15 (9 wt% Ni) catalysts (Ni:Y weight ratio = 9:0, 3:1, 3:2, 1:1) were prepared using a sol-gel method. The fresh as well as the catalysts used in CO2 reforming of methane were characterized using N-2-physisorption, XRD, FT-IR, XPS, UV, HRTEM, H-2-TPR, O-2-TPD and TG techniques. The results indicate that upon Y2O3 promotion, the Ni nanoparticles are highly dispersed on the mesoporous walls of SBA-15 via strong interaction between metal ions and the HO-Si-groups of SBA-15. The catalytic performance of the catalysts were evaluated at 700 degrees C during CH4/CO2 reforming at a gas hourly space velocity of 24 L g(cat)(-1) h(-1)(at 25 degrees C and 1 atm) and CH4/CO(2)molar ratio of 1. The presence of Y2O3 in NiO/SBA-15 results in enhancement of initial catalytic activity. It was observed that the 9 wt% Y-NiO/SBA-15 catalyst performs the best, exhibiting excellent catalytic activity, superior stability and low carbon deposition in a time on stream of 50 h. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Y-NiO/SBA-15 catalyst;Y2O3 segregation effects;CH4/CO2 reforming;Oxygen vacancies;High stability