NO Adsorption and Oxidation on Mn Doped CeO2 (111) Surfaces: A DFT+U Study

Abstract

The adsorption of NO molecules on Mn-doped CeO 2 (111) surfaces for NO oxidation has been studied by employing the periodic density functional theory plus U (DFT+U) method. Through our calculations, it is demonstrated how Mn-doped CeO 2 with superior NO oxidation activity benefits from the high mobility of the oxygen near the Mn cations. On unreduced Mn-doped CeO 2 (111) surfaces, the NO molecule preferentially interacted with the first neighboring O of the Mn cation, with the N also bonding to an Mn cation (E ads = -3.30 eV) or Ce cation (E ads = -2.90 eV). When NO adsorbs on the surface of defective Mn-doped CeO 2 with O 2 adsorbed in advance, an ONOO* four atoms species is formed on the surface (E ads = -2.51 eV and -2.02 eV), which is an intermediate and can decompose into NO 2 , NO 2 * and O*. The adsorption structure with higher adsorption energy has a closer geometry to NO 2 , indicating a deeper oxidation of NO. The calculation results indicate that the presence of Mn only has a strong effect on the nearby oxygen atoms and that the Mndoped CeO 2 surface has similar properties to a noble metal in NO oxidation catalysis. In DOS plots, the spin of the electron state of the adsorption structures involving the oxidation of NO is symmetric, indicating that electron transfer occurs from the slab to NO and strong covalent bonds are formed between N and O on the slab, which can also be confirmed by the charge density difference plots.

Stable Seamless Interfaces and Rapid Ionic Conductivity of Ca–CeO2/LiTFSI/PEO Composite Electrolyte for High‐Rate and High‐Voltage All‐Solid‐State Battery

“…Similar to previous results, a preliminary study of the structure of CeO 2 (111) surface shows that the O terminated surface is the energetically stable adsorption surface. [ 43 ] The significance of this atomic‐scale calculation from first principle is in line with the fundamental principle of SSEs systems in that, the TFSI − anion should be effectively immobilized on the surface of the substrate material so that cationic Li + ions can freely transport through the PEO/LiTFSI matrix near the Ca–CeO 2 . [ 44 ] To study this, the binding energy of Li + with TFSI − in LiTFSI and in the CeO 2 +LiTFSI with and without oxygen vacancy were calculated and shown in Figure 5 a,b and Figure S15 in the Supporting Information.…”

Rational Design of Transition Metal Co‐Doped Ceria Catalysts for Low‐Temperature CO Oxidation

“…Based on E vf , we screened the dopant candidates for TM elements Mn and Fe, Co, Ni, Ru, Rh, Pd, Ag, Ir, Os, Pt, and Au in groups VIII to XI and periods 4 to 6 (Figure b). These metals have all previously been shown to increase the catalytic activity of CeO 2 by single doping or impregnation …”

Deciphering Evolution Pathway of Supported NO3• Enabled via Radical Transfer from •OH to Surface NO3– Functionality for Oxidative Degradation of Aqueous Contaminants

“…Meanwhile, a portion of the Mn n + species may act as anchoring spots of NO Y – (Y = 2 or 3) formed via chemical fusion of NO/O 2 on or near Mn n + species, as reported previously. 36 , 37 In addition, labile oxygens (O α ) bound to surface Mn n + species are also prone to bind with NO/O 2 and generate NO 2 – /NO 3 – functionalities with mono - or bi -dentate configuration along with reductive transition of Mn n + to Mn ( n –1)+ . 38 , 39 (See boxes highlighted with yellow/red/orange in Figure 1 .)…”