The growth of CeO_x(111) thin films on Ru(0001)

Abstract Ceria has attracted great attention in recent years in the catalysis community. Metal catalysts supported on ceria exhibit a promising catalytic activity due to the ceria’s unique redox properties and oxygen storage capacity. The purpose of this paper is to look at the fundamental aspect of CeOx(111) thin films on Ru(0001). The investigation presented in this paper utilizes the surface science method to understand the properties of CeOx(111). In one component, through a series of XPS studies, it is shown that the deposition of Ce in the presence of oxygen on Ru(0001) can produce ceria thin films. Fully oxidized CeO2 can be obtained with an oxygen pressure of 2 x 10−7 Torr. With the decrease in the oxygen pressure, partially reduced CeOx films can be prepared. Moreover, STM images are collected from the CeO2 growth in the presence of 2×10−7 Torr of oxygen and partially reduced ceria with oxygen pressures of 8×10−8 Torr. These films can completely cover the Ru(0001) substrate. The measured step height is about 0.3 nm, which is consistent with the 0.313 nm spacing of O-Ce-O tri-layers in the CeO2(111) fluorite bulk structure.