Direct imaging of zirconia pillars in montmorillonite by analytical electron microscopy

Analytical electron microscopy was used to confirm the location of pillars of zirconia in pillared montmorillonite. Data show that the pillared clay i s of "high" quality, with surface areas ranging from 200 to 250 m(2)/g and (001) spacings in the 17-18 Angstrom range. The zirconia-rich pillars were observed using bright-field imaging, annular dark-field imaging, and energy -filtered imaging. The composition of the pillars was confirmed by performi ng nano-analysis using energy-dispersive X-ray spectroscopy and electron en ergy-loss spectroscopy. The pillars apparently have an irregular shape <50 Angstrom in size. The shape and relatively large size of the pillars sugges t that zirconia dispersion is not ideally distributed in this sample. This study is apparently the first report of electron microscopy observation of pillaring material in clays.