Hydrophilic Interaction Between Low-Coordinated Au and Water: H₂O/Au(310) Studied with TPD and XPS

Abstract

In this work, we study the relatively weak H 2 O− Au interaction on the highly stepped and anisotropic (310) surface with temperature-programmed desorption and X-ray photoelectron spectroscopy. Compared to Au(111), we report an enhanced adsorption energy of H 2 O−Au(310) as observed from the (sub)monolayer desorption peak. This peak shows zero-order desorption kinetics, which we do not explain with a typical two-phase coexistence model but rather by desorption from the ends of one-dimensional structures. These could cover both the steps and (part of) the terraces. We do not observe crystallization of ice clusters as observed on Au(111). This leads to the conclusion that this stepped surface forms a hydrophilic template for H 2 O adsorption. We also notice that the precise orientation of the steps determines the H 2 O binding strength. Despite the surface's enhanced H 2 O interaction, we do not observe any significant H 2 O dissociation. This indicates that the presence of low-coordinated Au atoms is not enough to explain the role of H 2 O in Au catalysis.

Interaction of CO with Gold Under Gas Phase and Electrochemical Environments

“…The adsorption energy per water was found to be -0.49 eV (Figure S27). This value is in good agreement with the adsorption of water on Au(310) in Ref 23 determined with TPD, which estimates a water adsorption energy of -0.49 to -0.55 eV. Since the adsorption of water is roughly as strong as CO adsorption under atmospheric conditions, water is likely to compete with CO adsorption in an electrochemical environment.…”

Shape tailored Pd nanoparticles’ effect on the photocatalytic activity of commercial TiO 2

“…As it can be seen in the case of P25 based composites, the presence of Pd was detrimental when phenol degradation was examined. A possible explanation could be that by the deposition of noble metals increases the hydrophylicity of the catalyst [36]. If this is the case, the adsorption of the water soluble intermediates could be facilitated.…”

Solvent-Free Mechanochemical Synthesis of ZnO Nanoparticles by High-Energy Ball Milling of ε-Zn(OH)2 Crystals

“…The presence of the 532.3 eV binding energy in all milled powders indicates the presence of a certain amount of a-Zn(OH) 2 on the surface of all samples, which is not surprising, as many other researchers have proven that even the purest ZnO nanoparticle powders always contain a hydroxide layer coating the surface of the particles [ 54 , 55 , 56 ]. The 532.3 eV peak could also be attributed to water molecules that are adsorbed on the surface, as the O–H 2 binding energy is 532.8 eV [ 57 , 58 ]. The chemical structure of the powders was also investigated by Fourier transform infrared spectroscopy (FTIR), and the results are presented in Figure S9 .…”