Environmental electron microscopy (ETEM) for catalysts with a closed E-cell with carbon windows

In a standard high-resolution electron microscope (Jeol 3010), an environmental sample holder designed by Jeol, has been used for in situ observations at the atomic scale of catalysts, during a chemical reaction. Experiments have been performed in H-2 and O-2 at a pressure LIP to 4 mbar at room temperature, and in the case of H-2, at various temperatures until 350 degrees C. For the first time, Au and Pd clusters supported on TiO2 and amorphous carbon have been observed with a windows-cell environmental electron microscopy (ETEM) system, with the resolution of the (111) lattice fringes. Au clusters have been cleaned in H-2 and have got the equilibrium shape of the fee crystals during annealing. The same Au particles can be observed during successive treatments under O-2 and H-2. For Pd clusters in situ exposed to O-2, the adhesion has decreased. (c) 2006 Elsevier B.V. All rights reserved.