Analytical TEM Observation of Gold Nano-Particles on Cerium Oxide

ABSTRACTThe structure of Au nano-particles supported on CeO2 was investigated by using an analytical transmission electron microscope (TEM). The shape change of Au particles was observed during TEM observation, such as shrinking down to a mono-atomic layer on the CeO2 substrate. The electron beam irradiation experiment revealed that the shape change of Au particles is concerning with the oxidation state or the density of oxygen vacancies of CeO2 substrate where the rapid desorption and adsorption of oxygen occurs. It was also found that the reduction by strong electron beam irradiation and subsequent oxidation generate the decoration of Au particles by cerium oxide.