CO And Ni Cluster Adsorption On Pr And Ce Doped Zirconia(111) Surface

This paper studies the adsorption of CO on doped ZrO₂ surface,influence of doping on ZrO₂ structure and oxygen vacancies formation energy and the adsorption of nickel atoms on doped Zr02 surface By first principles study.we got the following results:Firstly,through study structure and oxygen vacancy formation of ZrO₂ after doping can be found that oxygen vacancies are most likely to appear in ZrO₂?111?surface.Oxygen vacancy formation energy is 2.33 eV in undoped ZrO₂ supercell,oxygen vacancy formation energy is 2.54 eV and 2.91 eV for Ti and Pr doped ZrO₂,respectively.this suggests that Ti and Pr doping is conducive to the formation of oxygen vacancy.Pr doping have a smaller gap value of 1.41 eV,the gap of Ti doped system is 1.82 eV,the four oxygen atoms adjacent doping position have greater charge for Pr doped system than in Ti doped system,Pr doping have more obvious effect on the oxidizing and reducing of ZrO₂.Through calculation the surface energy of oxygen vacancy on different ZrO₂ surface shows that oxygen vacancy is easier to appear on the ZrO₂?111?surface.oxygen vacancy is more likely to formed on the outer surface of ZrO₂?111?.Secondly,we calculated the adsorption of CO on M-doped ZrO₂?111??M = Ce,Ca and Pr?.Calculations indicate that for the stoichiometric ZrO₂?111?surface,the preferential adsorption structure is the Zr-CO configuration.The adsorption energy of the Zr-CO configuration is larger for the M-doped ZrO₂?111??M = Ce,Ca and Pr?surface than for the stoichiometric one.The adsorption energy of the Zr-CO configuration is-0.73eV for the Pr-doped surface,-0.67eV for the Ce-doped surface,-0.41eV for the Ca-doped surface,-0.35eV for the stoichiometric ZrO₂?111?surface.Carbon monoxide adsorbed on Pr-doped monoclinic ZrO₂?111?surface is the most stable.Finally,we calculated the adsorption of Ni and Ni7 clusters on the Zr1-xCexO₂?111?surfaces?x=0,0.083,0.167,0.25 and 0.333?.Calculation studies based on the density of states?DOS?and Hirshfeld charge analysis demonstrate that the electronic interaction is mainly localized at the Ni-ZrO₂ interface.The isolated Ni atom on Zr02 is the positive charge,which shows that there is electron transfer from Ni to ZrO₂.For the isolated Ni atom on ZrO₂?111?surface,the preferential adsorption site is the Zr bridge site.For the Ni7 adsorbed on the stoichiometric and Ce-doped ZrO₂?111?surface,the Ni7 is negatively charge,and as the winner in the adsorbed process,Ni7 gets charged from Zr1-xCeaxO₂?111?surfaces.Ni7 on Zr0.667Ce0.333O₂?111?surface has a more stable adsorption energy.