Carbon dioxide adsorption on lanthanum zirconate nanostructured coating surface: a DFT study

Pyrochlore lanthanum zirconate (La2Zr2O7) is a very promising candidate material for thermal barrier coating applications. However it may deteriorate by oxidizing gas such as CO2 during operating conditions. This paper investigates CO2 gas adsorption on La2Zr2O7 nanostructured coating surfaces using the density functional theory calculations. CO2 adsorption energies on (001), (011) and (111) planes in the La-Zr bridge positions have been calculated. The most favorable CO2 adsorption occurs on the (111) plane, which is confirmed by electron charge transfer and charge density difference analyses. La2Zr2O7 surface energies on (001), (011) and (111) planes have been calculated. Results show that (011) plane is the most thermodynamically stable plane due to its lowest surface energy.