Aberration-corrected HRTEM study of Mn-doped tungstated zirconia catalysts

Solid acids as tungstated zirconia have received significant attention for isomerization reactions. The identification of catalytically active WOx nanostructures supported on ZrO2 presents significant challenges, since different surface WOx species have been proposed. In this work the results of the structure and domain size of the very small tungsten oxides species (WOx) supported on zirconia are presented. Electron micrographs of a Mn–WOx–ZrO2 active catalyst obtained in an aberration-corrected high resolution transmission electron microscope (HRTEM) allowed direct imaging of subnanometer tungsten oxide, from mono- to poly-tungstate WOx species as well as the presence of tungsten oxides crystallites (WO3) over ZrO2 in a homogeneous distribution. It is shown that it is feasible to identify and measure these WOx nanospecies supported on zirconia by using an aberration-corrected HRTEM.

Figure optionsDownload high-quality image (270 K)Download as PowerPoint slideHighlights
► Mn–WOx–ZrO2 catalysts were studied by aberration-corrected HRTEM.
► Defocus was used to identify the different WOx surface species.
► Images at optimum-focus conditions were obtain in order to project the atomic structure of WOx species.