Highly active and stable Ni/SBA-15 catalysts prepared by a 'two solvents' method for dry reforming of methane

摘要

Two series of Ni (2.5-7.5 wt%) and Ce (6 wt%) containing SBA-15 catalysts were prepared and tested in dry reforming of methane, a promising route for the production of syngas. Both Ni and Ce species were introduced in the organized mesoporous silica support in the form of nitrate salts using the "two solvents" procedure that is known to favor metal dispersion inside the porosity. Samples characterizations by N-2 sorption, SAXS, XRD, SEM and TEM indicate good preservation of the porosities after Ni deposition and calcination as well as formation of NiO nanoparticles entrapped in the porous channels. In the cerium-enriched samples, the CeO2 nanoparticles are also highly dispersed. After reduction, all the catalysts show high activity and selectivity towards H-2 and CO at atmospheric pressure with full CH4 conversion below 650 degrees C. In these conditions, there is no significant promotional effect by ceria. Moreover, prolonged tests performed at 500 degrees C for 12 h reveal a high stability of the catalysts. The absence of deactivation throughout the catalytic run at this temperature agrees with the low carbon amount detected after test and with the limited sintering of the Ni nanoparticles in the used catalysts. The positive effect of the SBA-15 mesoporous channels towards stabilization of the supported particles is discussed. (C) 2015 Elsevier Inc. All rights reserved.