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 WO _x nanostructures supported on ZrO₂ presents significant challenges, since different surface WO_x species have been proposed. In this work the results of the structure and domain size of the very small tungsten oxides species (WO_x) supported on zirconia are presented. Electron micrographs of a Mn-WO_x-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 WO_x 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 WO_x nanospecies supported on zirconia by using an aberration-corrected HRTEM.