Adsorption and migration of single metal atoms on the calcite (10.4) surface

Abstract

Transition metal atoms are one of the key ingredients in the formation of functional 2D metal organic coordination networks. Additionally, the co-deposition of metal atoms can play an important role in anchoring the molecular structures to the surface at room temperature. To gain control of such processes requires the understanding of adsorption and diffusion properties of the different transition metals on the target surface. Here, we used density functional theory to investigate the adsorption of 3d (Ti, Cr, Fe, Ni, Cu), 4d (Zr, Nb, Mo, Pd, Ag) and 5d (Hf, W, Ir, Pt, Au) transition metal adatoms on the insulating calcite (10.4) surface. We identified the most stable adsorption sites and calculated binding energies and corresponding ground state structures. We find that the preferential adsorption sites are the Ca-Ca bridge sites. Apart from the Cr, Mo, Cu, Ag and Au all the studied metals bind strongly to the calcite surface. The calculated migration barriers for the representative Ag and Fe atoms indicates that the metal adatoms are mobile on the calcite surface at room temperature. Bader analysis suggests that there is no significant charge transfer between the metal adatoms and the calcite surface.

Zirconium and hafnium fractionation and distribution of Rare Earth Elements in neutral–alkaline waters: Case study of Lake Van hydrothermal system, Turkey

“…and 10 and should correspond to the higher binding energy between Hf and {104} calcite surface relative to Zr as estimated by theoretical ab initio calculations (Pinto et al, 2017). Our results support the Zr/Hf fractionation observed by Firdaus et al (2011Firdaus et al ( , 2018 during Fe-oxyhydroxide formation.…”

Palladium Dimer Supported on Mo2CO2(MXene) for Direct Methane to Methanol Conversion

“…The ELF in Figure c shows that the electrons are mainly spread around the oxygen and carbon atoms in Pd 1 /Mo 2 CO 2 , indicating notable electron transfer from metals to O/C atoms. The Bader charge analysis indicates that the charge of the Pd single atom on Mo 2 CO 2 is + 0.69 | e |, which is higher than that of other 2D materials, such as calcite and g ─C 3 N 4 . Therefore, the HCP hollow site is the most stable position for anchoring the Pd single atom on Mo 2 CO 2 through efficient electron transfer.…”

Comparison of CH4 and CO2 Adsorptions onto Calcite(10.4), Aragonite(011)Ca, and Vaterite(010)CO3 Surfaces: An MD and DFT Investigation

“…Likewise, the k-points are automatically set as 4 × 3 × 1, 3 × 3 × 1, and 4 × 4 × 1 for the adsorption systems on the substrates of calcite(10.4), aragonite(011)Ca, and vaterite(010)CO 3 respectively. We also noticed that the cutoff energy of 450 eV and k-point grid separation of around 0.03 Å −1 have been successfully implemented in the adsorption system containing the calcite(10.4) surface 70…”