The hydrolysis of borohydride on the Ag(111) surface is explored theoretically to obtain the in-depth reaction mechanism. Many heterogeneously catalyzed reactions like this involve the adsorption of charged species on metals. DFT calculations of charged systems, with periodic boundaries, face serious problems, concerning convergence and reliability of the results. To study the heterogeneously catalyzed reactions, a simple method to calculate the adsorption energy of charged systems in metallic periodic cells is proposed. In this method, a counter ion is placed at a non-interactive distance, in an aqueous medium, so that the calculated system is neutral. Bader analysis is used to validate that the calculated couple is charged correctly. Adsorption energies of F, Cl, Br, OH, BH, ClO and H ions on the Ag(111) surface in an aqueous medium were determined using Na and K as counter ions, to evaluate the performance of this method. The adsorption of the divalent ions S, Se and SO on different surfaces was studied as well. Then this method was used to explore the hydrolysis of BH ions, which have a high theoretical hydrogen storage capacity, on the Ag(111) surface. The results point out that during the catalytic hydrolysis only one hydrogen atom from borohydride is transferred to the surface. In the first step one hydrogen atom from BH is transferred to the silver surface; this H atom reacts with a hydrogen atom that is released from an adsorbed water molecule; in addition, a hydrogen molecule is released in the second step (one atom from *BH and one from *HO). Thus, the mechanisms of the catalyzed reductions by BH and the hydrogen evolution reactions must be reconsidered.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d1cp03895h | DOI Listing |
J Phys Chem Lett
January 2025
Clausius Institut für Physikalische und Theoretische Chemie, Universität Bonn, Bonn 53115, Germany.
The carpet growth of alkali halide (AH) layers across step edges of substrates enables the growth of seamless and continuous large domains. Yet, information about how the AH layer adapts continuously to the height difference between the terraces on the two sides of a step is only described by continuum models, which do not give details of the ionic displacements. Here, we present a first study of thin epitaxial KCl(100) layers grown on the Ag(111) surface by scanning tunneling microscopy that provides atomistic details for the first time.
View Article and Find Full Text PDFChemistry
January 2025
Ruhr University Bochum: Ruhr-Universitat Bochum, Organic Chemistry II, GERMANY.
It is well established that the confinement of reactants to two dimensions influences their reactivity. However, such confinement is often dominated by charge transfer effects between the reactants and the confining walls, in particular if the walls are conductive. Also, the reactivity of carbenes on metal surfaces is significantly affected by the charge transfer between the carbene and the metal, rendering the carbene more nucleophilic or electrophilic.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Laboratory for Chemistry and Life Science (CLS), Institute of Integrated Research, Institute of Science Tokyo, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
ConspectusThe design of properties and functions of molecular assemblies requires not only a proper choice of building blocks but also control over their packing arrangements. A highly versatile unit in this context is a particular type of triptycene with substituents at the 1,8,13-positions, called tripodal triptycene, which offers predictable molecular packing and multiple functionalization sites, both at the opposite 4,5,16- or 10 (bridgehead)-positions. These triptycene building blocks are capable of two-dimensional (2D) nested hexagonal packing, leading to the formation of 2D sheets, which undergo one-dimensional (1D) stacking into well-defined "2D+1D" structures.
View Article and Find Full Text PDFACS Nano
January 2025
Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam-Golm, Germany.
The reduced dimensionality of thin transition metal dihalide films on single-crystal surfaces unlocks a diverse range of magnetic and electronic properties. However, achieving stoichiometric monolayer islands requires precise control over the growth conditions. In this study, we employ scanning probe microscopy to investigate the growth of MnI on Ag(111) via single-crucible evaporation.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Department of Physics, University of Basel, Klingelbergstrasse 82, Basel, 4056, Switzerland.
Many-body interactions in metal-organic frameworks (MOFs) are fundamental for emergent quantum physics. Unlike their solution counterpart, magnetization at surfaces in low-dimensional analogues is strongly influenced by magnetic anisotropy (MA) induced by the substrate and still not well understood. Here, on-surface coordination chemistry is used to synthesize on Ag(111) and superconducting Pb(111) an iron-based spin chain by using pyrene-4,5,9,10-tetraone (PTO) precursors as ligands.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!