Structural and electronic properties of NM-doped ceria(NM = Pt,Rh): a first-principles study

Abstract

The effects of noble metal (NM) dopants(NM = Pt,Rh) on the structural and electronic properties of ceria are studied using a densityfunctional theory (DFT) method, with the inclusion of on-site Coulomb interaction(DFT+U). It is found that these NM dopants give rise to large perturbations of the atomic andelectronic structures of ceria and induce metal-induced gap states at the Fermi levelsuitable for accommodating extra electrons, thereby lowering the reduction energy of ceriaand making the NM-doped cerias more reducible than pure ceria. This mechanism forfacilitating the reduction of ceria is different from that of Zr-doped ceria where theincreased reducibility is largely due to the structural distortions and not to electronicmodifications.