Mesoporous silica-pillared kenyaite and magadiite as catalytic support for partial oxidation of methane

Abstract

Highly ordered mesoporous silica-pillared kenyaite (SPK) and magadiite (SPM) were prepared by the hydrolysis of tetraethylorthosilicate (TEOS) through the catalytic effects of dodecylamine (DDA) in the interlayer space. SPM and SPK exhibited regular gallery heights of 3.0 and 3.4 run, narrow pore size distributions of 2.5 and 3.0 nm and large specific surface areas of 877 and 1029 m(2)/g, respectively. The sharpness of the door peak for SPK was well-preserved even after heating up to 800 degrees C in air, while the peak for SPM collapsed between 700 and 800 degrees C. A uniform spacing of 2-3 nm between the layers were obtained from the TEM images of SPM and SPK. SPK and SPM impregnated with 5 wt% of Ni and Pd were examined as potential catalysts in the partial oxidation of methane at 750 degrees C. The Ni/SPK, Ni/SPM and Pd/SPK catalysts showed higher methane conversions, which remained stable for almost 100 h of heating. Especially, the Pd/SPK catalyst exhibited high selectivity and stability to H-2. The results indicate that the SPK and SPM products are highly applicable as catalytic supports in high temperature reactions. (C) 2009 Elsevier Inc. All rights reserved.