Thermal stability of zirconia-doped ceria surfaces: A first-principles molecular dynamics study

摘要

Ceria, one of the most important functional rare-earth oxides, is widely used in many technically important industry fields. However, pure ceria is known to have poor thermal stability. Zirconia doping is usually employed to improve its thermal stability and achieve high OSC (oxygen storage capacity) performances under severe conditions. We have performed first-principles molecular dynamics simulations at a series of temperatures and proposed two parameters, i.e. the thermal displacement rate and the phase segregation degree, to describe the structural change of the ceria-zirconia solid solution surfaces. Based on our molecular dynamics simulations the temperature predicted at which the specific surface area dramatically decreases is in good agreement with previous experimental observations.