Recent Progress in Hydrogen Electrocatalysis

While density functional theory (DFT) at the generalized gradient approximation (GGA) level has made great success in catalysis, it fails in some important systems, such as the adsorption of the oxygen molecule on the Ag(111) surface. Previous DFT studies at the GGA level revealed theoretical inconsistencies on the adsorption energies and dissociation barriers of O2 on Ag(111) in comparison with the experimental conclusion. In this study, the SCAN-rVV10 method at the meta-GGA level with the non-local van der Waals (vdW) force correction was used to reinvestigate the adsorption properties of O2 on the Ag(111) surface. The SCAN-rVV10 results successfully confirm the experimental observation that both molecular and dissociative adsorption can exist for oxygen on Ag(111). The calculated adsorption energy for the physisorption state and the relevant dissociation energy barrier are close to the experimental data. It demonstrates that SCAN-rVV10 can outperform functionals at the GGA level for O2/Ag(111). Therefore, our findings suggest that SCAN-rVV10 can be the desired method for systems where the correct description of intermediate ranged vdW forces are essential, such as the physisorption of small molecules on the solid surface.

show abstract

“…The PBE results were almost identical to the reported data 51,52 . However, SCAN-rVV10 and SCAN downshift by roughly 0.5 eV.…”

Section: Oxygen Molecule Ag Crystal and Ag(111)supporting

confidence: 87%

Reinvestigating oxygen adsorption on Ag(111) by using strongly constrained and appropriately normed semi-local density functional with the revised Vydrov van Voorhis van der Waals force correction

Hinsch

Liu

Wang

2021

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…This can be rationalized by looking at the connection between the substrate density of states (DOS) at E F and the binding energy of an adsorbate. All the substrates considered in this work possess wide s and p bands, while the contribution of the narrower d bands to the DOS at E F increases from Ag to Pt [53,55]. The hybridization between the outer 6s6p5d orbitals of the RE with the substrate conduction electrons produces hybrid RE-metal bands, the DOS of which at E F is enhanced when substrate d bands are available [56].…”

Section: A 4 F Occupancy Of Re Adatomsmentioning

confidence: 93%

“…Here, the RE atoms are sorted by their value of E f d + δE c , while the substrates are sorted by the density of states (DOS) at the Fermi level E F as reported in Ref. [53]. The trend in E f d + δE c suggests that the stability of the trivalent state among the investigated elements is the lowest for Tm and the highest for Er [20,22,54].…”

Section: A 4 F Occupancy Of Re Adatomsmentioning

confidence: 99%

4f occupancy and magnetism of rare-earth atoms adsorbed on metal substrates

et al. 2017

View full text Add to dashboard Cite

We report x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements as well as multiplet calculations for Dy, Ho, Er, and Tm atoms adsorbed on Pt(111), Cu(111), Ag(100), and Ag(111). In the gas phase, all four elements are divalent and we label their 4f occupancy as 4f n . Upon surface adsorption, and depending on the substrate, the atoms either remain in that state or become trivalent with 4f n−1 configuration. The trivalent state is realized when the sum of the atomic correction energies (4f →5d promotion energy E f d + intershell coupling energy δE c ) is low and the surface binding energy is large. The latter correlates with a high substrate density of states at the Fermi level. The magnetocrystalline anisotropy of trivalent RE atoms is larger than the one of divalent RE atoms. We ascribe this to the significantly smaller covalent radius of the trivalent state compared to the divalent one for a given RE element. For a given valency of the RE atom, the anisotropy is determined by the overlap between the spd states of the RE and the d states of the surface. For all investigated systems, the magnetization curves recorded at 2.5 K show absence of hysteresis indicating that magnetic relaxation is faster than about 10 s.

show abstract

“…In these devices, the large kinetic barriers to multi-electron activation of small molecules are surmounted by heterogeneous catalysts that bind reaction intermediates at surface active sites. 4,5 Despite their central role in virtually all energy storage and release reactions, the mechanistic details of proton-electron coupling at catalyst surfaces remain poorly understood.…”

Section: Introductionmentioning

confidence: 99%

Donor-Dependent Kinetics of Interfacial Proton-Coupled Electron Transfer

Jackson

Surendranath

2016

J. Am. Chem. Soc.

View full text Add to dashboard Cite

The effect of the proton donor on the kinetics of interfacial concerted proton-electron transfer (CPET) to polycrystalline Au was probed indirectly by studying the rate of hydrogen evolution from trialkylammonium donors with different steric profiles, but the same pKa. Detailed kinetic studies point to a mechanism for HER catalysis that involves rate-limiting CPET from the proton donor to the electrode surface, allowing this catalytic reaction to serve as a proxy for the rate of interfacial CPET. In acetonitrile electrolyte, triethylammonium (TEAH(+)) displays up to 20-fold faster CPET kinetics than diisopropylethylammonium (DIPEAH(+)) at all measured potentials. In aqueous electrolyte, this steric constraint is largely lifted, suggesting a key role for water in mediating interfacial CPET. In acetonitrile, TEAH(+) also displays a much larger transfer coefficient (β = 0.7) than DIPEAH(+) (β = 0.4), and TEAH(+) displays a potential-dependent H/D kinetic isotope effect that is not observed for DIPEAH(+). These results demonstrate that proton donor structure strongly impacts the free energy landscape for CPET to extended solid surfaces and highlight the crucial role of the proton donor in the kinetics of electrocatalytic energy conversion reactions.

show abstract

Recent Progress in Hydrogen Electrocatalysis

Cited by 27 publications

References 34 publications

Reinvestigating oxygen adsorption on Ag(111) by using strongly constrained and appropriately normed semi-local density functional with the revised Vydrov van Voorhis van der Waals force correction

Reinvestigating oxygen adsorption on Ag(111) by using strongly constrained and appropriately normed semi-local density functional with the revised Vydrov van Voorhis van der Waals force correction

4f occupancy and magnetism of rare-earth atoms adsorbed on metal substrates

Donor-Dependent Kinetics of Interfacial Proton-Coupled Electron Transfer

Contact Info

Product

Resources

About