Visualizing the gas-sensitive structure of the CuZn surface in methanol synthesis catalysis.

Methanol formation over Cu/ZnO catalysts is linked with a catalytically active phase created by contact between Cu nanoparticles and Zn species whose chemical and structural state depends on reaction conditions. Herein, we use variable-temperature scanning tunneling microscopy at elevated pressure conditions combined with X-ray photoelectron spectroscopy measurements to investigate the surface structures and chemical states that evolve when a CuZn/Cu(111) surface alloy is exposed to reaction gas mixtures. In CO hydrogenation conditions, Zn stays embedded in the CuZn surface, but once CO gas is added to the mixture, the Zn segregates onto the Cu surface.

Origin of hydroxyl pair formation on reduced anatase TiO(101).

The interaction of water with metal oxide surfaces is of key importance to several research fields and applications. Because of its ability to photo-catalyze water splitting, reducible anatase TiO (a-TiO) is of particular interest. Here, we combine experiments and theory to study the dissociation of water on bulk-reduced a-TiO(101).

The interface ofgrown single-layer epitaxial MoSon SrTiO(001) and (111).

SrTiO(STO) is a versatile substrate with a high dielectric constant, which may be used in heterostructures with 2D materials, such as MoS, to induce interesting changes to the electronic structure. STO single crystal substrates have previously been shown to support the growth of well-defined epitaxial single-layer (SL) MoScrystals. The STO substrate is already known to renormalize the electronic bandgap of SL MoS, but the electronic nature of the interface and its dependence on epitaxy are still unclear.

Atomic-Scale View of the Oxidation and Reduction of Supported Ultrathin FeO Islands.

By means of scanning tunneling microscopy (STM) measurements, we studied the oxidation and reduction of FeO bilayer islands on Au(111) by oxygen (O) and hydrogen (H), respectively. The FeO islands respond very dynamically toward O, with the coordinatively unsaturated ferrous (CUF) sites at the island edges being essential for O dissociation and O atom incorporation. An STM movie obtained during oxidation reveals how further O molecules can dissociate after the consumption of all initially existing CUF sites through the formation of new CUF sites.

Supramolecular Corrals on Surfaces Resulting from Aromatic Interactions of Nonplanar Triazoles.

Interaction forces between aromatic moieties, often referred to as π-π interactions, are an important element in stabilizing complex supramolecular structures. For supramolecular self-assembly occurring on surfaces, where aromatic moieties are typically forced to adsorb coplanar with the surface, the possible role of intermolecular aromatic interactions is much less explored. Here, we report on unusual, ring-shaped supramolecular corral surface structures resulting from adsorption of a molecule with nonplanar structure, allowing for intermolecular aromatic interactions.