An improved d-band model of the catalytic activity of magnetic transition metal surfaces

Abstract

The d-band center model of Hammer and Nørskov is widely used in understanding and predicting catalytic activity on transition metal (TM) surfaces. Here, we demonstrate that this model is inadequate for capturing the complete catalytic activity of the magnetically polarized TM surfaces and propose its generalization. We validate the generalized model through comparison of adsorption energies of the NH3 molecule on the surfaces of 3d TMs (V, Cr, Mn, Fe, Co, Ni, Cu and Zn) determined with spin-polarized density functional theory (DFT)-based methods with the predictions of our model. Compared to the conventional d-band model, where the nature of the metal-adsorbate interaction is entirely determined through the energy and the occupation of the d-band center, we emphasize that for the surfaces with high spin polarization, the metal-adsorbate system can be stabilized through a competition of the spin-dependent metal-adsorbate interactions.

Elucidating energy scaling between atomic and molecular adsorbates in the presence of solvent

“…The d ‐band model is a widely accepted method to interpret interactions between adsorbates and metals 53‐56 . According to this model, the variation of adsorption energies between metal surfaces can be attributed to differences in the d ‐band structures of the various metals.…”

“…The d-band model is a widely accepted method to interpret interactions between adsorbates and metals. [53][54][55][56] According to this model, the variation of adsorption energies between metal surfaces can be This therefore suggests that the interaction between water and the adsorbate occurs nearly exclusively through the hydrogen bond (surface interactions), rather than indirectly through modification of the metal electronic states.…”

“…The fcc(100) facet is also frequently chosen as a catalyst model surface due to its relatively high structural stability (typically behind only the fcc(111) facet) and increased reactivity derived from a lower coordination number of surface metal atoms. 56,[58][59][60][61][62] We therefore chose Simplified scheme ("with water" case shown)…”

Enhanced propylene oxide selectivity for gas phase direct propylene epoxidation by lattice expansion of silver atoms on nickel nanoparticles

“…Similarly, the synthesis of Ni@Ag core-shell nanoparticle and tailoring of Ag-Ag interatomic distance on Ag shell atoms may also provide a new way to create a longer Ag-Ag distance to reduce the total combustion route. Such longer interatomic Ag distance resulted from lesser surface packing can raise the surface d band centre to promote higher activity as according to the d band theory [51][52][53][54]. This can account for the higher propylene oxide activity and selectivity observed for the first time on Ni@Ag core-shell catalysts.…”

Recent Studies on Bifunctional Perovskite Electrocatalysts in Oxygen Evolution, Oxygen Reduction, and Hydrogen Evolution Reactions under Alkaline Electrolyte

“…In order to screen an effective ORR catalyst, the DFT calculations suggest an upward shift in the position of metal d states relative to the Fermi level, otherwise known as the d‐band center, which results in an upward shift in anti‐bonding 2p states leading to less electron filling, therefore yielding a strong bond . A wide range of non‐noble metals and their oxides and carbon materials have been screened as stable and potential ORR catalysts in alkaline media; whereas, Pt‐based catalysts are the mainstream in acidic condition…”