OH formation and H₂adsorption at the liquid water–Pt(111) interface

Abstract

The liquid water–Pt(111) interface is studied with constant temperature ab initio molecular dynamics to explore the importance of liquid water dynamics on catalytic reactions such as the oxygen reduction reaction in PEM fuel cells.

Energy–entropy competition in cation–hydroxyl interactions at the liquid water–Pt(111) interface

“…The shift to lower electrostatic potential indicates a free energy stabilization of adsorbed *OH species by Li + ions. [8][9][10][11] We obtain the free energy stabilization of adsorbed *OH due to Li + or K + situated at the liquid water-Pt(111) interface by modeling a liquid water film on Pt(111). The *OH stabilization is taken as the difference in the free energy cost of moving the Li + /K + cation from the liquid water-Pt(111) interface into the liquid water film with and without one *OH species on the surface.…”

“…The water-Pt(111) interfaces are set up in the ASE program 12 and modeled as (32-nOH)H2O molecules on top of a 3 × 4 orthogonal Pt(111) surface with a thickness of four atomic layers (nOH is the number of adsorbed *OH, i.e 0 or 1). The interfaces are studied by constant temperature AIMD simulations performed in VASP, [13][14][15][16] where a Nose thermostat 17 keeps the temperature around 350 K. The AIMD simulations utilize density functional theory (DFT) calculations with 350 eV plane-wave energy cut-off and PBE 18 with the D3 19 van der Waals correction to approximate exchange-correlation effects (computational details are identical to those used in ref 11 ). Furthermore, metadynamics [20][21][22][23] is used in combination with AIMD to obtain Li + /K + adsorption-solvation free energy profiles and the interactions between Li + /K + and adsorbed *OH.…”

Synergistic adsorptions of Na2CO3and Na2SiO3on calcium minerals revealed by spectroscopic andab initiomolecular dynamics studies

“…At the moment, although the adsorption of Na 2 SiO 3 species has been considerably investigated, 29,[32][33][34][35] very few studies have been conducted on the Na 2 CO 3 /Na 2 SiO 3 system in otation 17,28,31,36 and the synergistic effects exhibited by this reagent combination are still poorly understood. Some authors have successfully investigated surface reactivity and synergistic adsorptions/ reactions by Fourier transform infrared spectroscopy (FTIR), [37][38][39][40] by X-ray photoelectron spectroscopy (XPS), [41][42][43] and by ab initio molecular dynamics (AIMD) 37,[44][45][46] with couplings between the above-mentioned techniques. In the present study, we use a combination of diffuse reectance infrared Fourier transform spectroscopy (DRIFTS), XPS, and AIMD simulations to gain an understanding of the molecular mechanisms involved in the Na 2 SiO 3 adsorption onto bare surfaces and onto surfaces prior treated with Na 2 CO 3 .…”

Solvation at Metal/water Interfaces: An Ab Initio Molecular Dynamics Benchmark of Common Computational Approaches

“…Regardless, comparable data to our test set is still limited to the electrochemical model system Pt(111). We find good agreement for *CO 56 but only limited agreement for *OH 44 on Pt(111). For the latter, we found a deviation of -0.26 eV, where it should be noted that the considered reactions differ, i.e.…”

“…4and 5. Pt(111) shows a pronounced double O-peak, indicative of a bilayer structure9,32,44,54 . Consistent with a previous report42 , this feature appears to a lesser degree on Cu(111).…”