XAS studies on Pd/Ce-based mixed oxides nanotubes

L. M. ACUÑA; F. F. MUÑOZ; D. G. LAMAS; M. C. A. FANTINI; R. O. FUENTES

Campinas

Encuentro; RAU 20; 2010

LNLS-CNPEM

The wide use of Ce-based mixed oxides as catalyst components has prompted a renewed interest in the preparation of these materials in the form of nanosized, high surface area powders. In this context, we have been reported recently the preparation of nanotubes of Ce-based mixed oxides: ZCE (ZrO2-CeO2) and GDC (Gd2O3-CeO2), which are attractive for several reasons. Firstly, nanotubes with sufficiently small dimensions would have high specific surface areas (SSAs) which would lead to high activities, good atomic efficiencies and rapid response to changing conditions in catalyst systems. Secondly, the tubular nanostructure, in itself, may confer additional advantages, such as higher thermal, chemical and structural stability. In the present work, we report on the preparation of Pd/ZCE and Pd/ GDC mixed oxide nanotubes using such a technique. The nanotubes were synthesized using a commercial polycarbonate membrane (with pore size of 800 nm) as a template. In order to determine the effect of Pd incorporation on structural properties, the resulting nanotubes were studied by employing X-ray absorption spectroscopy (XANES and EXAFS).2-CeO2) and GDC (Gd2O3-CeO2), which are attractive for several reasons. Firstly, nanotubes with sufficiently small dimensions would have high specific surface areas (SSAs) which would lead to high activities, good atomic efficiencies and rapid response to changing conditions in catalyst systems. Secondly, the tubular nanostructure, in itself, may confer additional advantages, such as higher thermal, chemical and structural stability. In the present work, we report on the preparation of Pd/ZCE and Pd/ GDC mixed oxide nanotubes using such a technique. The nanotubes were synthesized using a commercial polycarbonate membrane (with pore size of 800 nm) as a template. In order to determine the effect of Pd incorporation on structural properties, the resulting nanotubes were studied by employing X-ray absorption spectroscopy (XANES and EXAFS).