Electronic Oxide–Metal Strong Interaction (EOMSI)

Abstract

Strong metal–support interaction of supported metal catalysts is an important concept to describe the effect of metal–support interactions on the structures and catalytic performances of supported metal particles. By using an example of CeOx adlayers supported on Ag nanocrystals, herein a concept of electronic oxide–metal strong interaction (EOMSI) is put forward; this interaction significantly affects the electronic structures of oxide adlayers through metal‐to‐oxide charge transfer. The EOMSI can stabilize oxide adlayers in a low oxidation state under ambient conditions, which individually are not stable; moreover, the oxide adlayers experiencing the EOMSI are resistant to high‐temperature oxidation in air to a certain extent. Such an EOMSI concept helps to generalize the strong influence of oxide–metal interactions on the structures and catalytic performance of oxide/metal inverse catalysts, which have been attracting increasing attention.

Metal–Support Interactions in Metal/Oxide Catalysts and Oxide–Metal Interactions in Oxide/Metal Inverse Catalysts

“…Later, surface science studies of well-defined oxide/metal model inverse catalysts have extensively demonstrated that, with the occurrence of OMI, oxide nanoparticles and thin films on metal single crystals exhibit electronic structures and chemical properties different from those found in bulk phases. − Recently, oxide/metal inverse powder catalysts via depositions of oxide nanoparticles on supported or unsupported metal particles have emerged as a novel type of efficient catalysts, in which the observed OMI was found similar to those in the corresponding model inverse catalysts. − For example, CeO x NPs on Au(111) and Cu(111) substrates and on Ag nanocrystals all exhibited rich oxygen vacancies. − FeO bilayer film and islands on Pt(111) and Pt nanoparticles are stable under reductive atmospheres but get oxidized into FeO 2 under oxidative atmospheres. ,, The OMI usually occurs via electron transfer between metal substrates and supported oxide nanostructures, which is herein defined as EOMI. Very recently, a concept of EOMSI was put forward to specifically describe the strong EOMI capable of stabilizing supported oxide nanostructures in a low-oxidation state under an ambient condition, which individually is not stable, via charge transfer from metal substrates to supported oxide nanostructures. Moreover, the supported oxide nanostructures experiencing the EOMSI are resistant to high-temperature oxidation in air to certain an extent.…”

“…82,90,91 The OMI usually occurs via electron transfer between metal substrates and supported oxide nanostructures, which is herein defined as EOMI. Very recently, a concept of EOMSI 92 was put forward to specifically describe the strong EOMI capable of stabilizing supported oxide nanostructures in a low-oxidation state under an ambient condition, which individually is not stable, via charge transfer from metal substrates to supported oxide nanostructures. Moreover, the supported oxide nanostructures experiencing the EOMSI are resistant to high-temperature oxidation in air to certain an extent.…”

“…It was also found that Ag cubes enclosed by Ag{100} facets with a higher Fermi level exhibited stronger CeO x -Ag EOMI than Ag triangle plates enclosed by Ag{111} facets with a lower Fermi level, supporting the occurrence of Ag → CeO x charge transfer. Later, these authors put forward a concept of electronic oxide−metal strong interactions (EOMSI) 92 to describe the oxide−metal EOMI that is strong enough to stabilize supported oxide adlayers in a low-oxidation state under an ambient condition, which individually is not stable. Moreover, the supported oxide adlayers experiencing the EOMSI are resistant to high temperature oxidation in air to certain an extent.…”

“…(c) Schematic illustration of Ag-to-CeO x charge transfer in CeO x /C–Ag and CeO x /T-Ag inverse catalysts. Reprinted with permission from ref . Copyright 2020 Wiley-VCH.…”

Superior efficiency of BN/Ce2O3/TiO2 nanofibers for photocatalytic hydrogen generation reactions

“…The shift of the N 1s peak to lower binding energy in BCET2 compared to the BT sample by 0.02 eV proves the engagement of BN nanosheets with Ce2O3 and TiO2 nanofibers [8]. According to the reported literatures [65], [66], [67], Ce2O3 will be stabilized through interaction by metal (Ag) and the charge transfer can stabilize Ce2O3. According to our results, there is charge transfer between Ce-Ti, and this interaction has stabilized Ce in +3 oxidation state.…”