Commercially available zirconia-tungstate as a benchmark catalytic material

The textural and catalytic properties of commercially available zirconia-tungstate were examined for comparison with samples in the literature. The materials were characterized using nitrogen adsorption, X-ray powder diffraction and n-butane isomerization. The commercially available samples were catalytically active in the isomerization of n-butane with activation in the range 1073-1173 K. Maximum catalytic activity occurred on the material with 12 wt% W activated at 1073 K - the loading and activation temperature required to yield saturation coverage of tungstate on zirconia. Zirconia-tungstate exhibited overall specific activities comparable to those of previously reported samples, but noticeably less than that achieved with commercially available zirconia-sulfate. Furthermore, the microporous commercial samples required activation in static air to retard crystallite growth of zirconia and thus retain surface areas similar to those of previously prepared samples. This study strengthened the current understanding of the behavior of zirconia-tungstate and demonstrated its use as a benchmark sample for the future. (C) 1999 Elsevier Science B.V. All rights reserved.