Enhancing Activity and Stability of Pd-on-TiO Single-Atom Catalyst for Low-Temperature CO Oxidation through Local Environment Tailoring.

The development of efficient Pd single-atom catalysts for CO oxidation, crucial for environmental protection and fundamental studies, has been hindered by their limited reactivity and thermal stability. Here, we report a thermally stable TiO-supported Pd single-atom catalyst that exhibits enhanced intrinsic CO oxidation activity by tunning the local coordination of Pd atoms via H treatment. Our comprehensive characterization reveals that H-treated Pd single atoms have reduced nearest Pd-O coordination and form short-distanced Pd-Ti coordination, effectively stabilizing Pd as isolated atoms even at high temperatures.

Molecular Permeation in Freestanding Bilayer Silica.

Graphene and other single-layer structures are pursued as high-flux separation membranes, although imparting porosity endangers their crystalline integrity. In contrast, bilayer silica composed of corner-sharing (SiO) units is foreseen to be permeable for small molecules due to its intrinsic lattice openings. This study sheds light on the mass transport properties of freestanding 2D SiO upon using atomic layer deposition (ALD) to grow large-area films on Au/mica substrates followed by transfer onto SiN windows.

Binding and stability of MgO monomers on anatase TiO(101).

In catalysis, MgO is often used to modify the acid-base properties of support oxides and to stabilize supported metal atoms and particles on oxides. In this study, we show how the sublimation of MgO powder can be used to deposit MgO monomers, hither on anatase TiO(101). A combination of x-ray electron spectroscopy, high-resolution scanning tunneling microscopy, and density functional theory is employed to gain insight into the MgO monomer binding, electronic and vibrational properties, and thermal stability.

Creating self-assembled arrays of mono-oxo (MoO) species on TiO(101) via deposition and decomposition of (MoO) oligomers.

Hierarchically ordered oxides are of critical importance in material science and catalysis. Unfortunately, the design and synthesis of such systems remains a key challenge to realizing their potential. In this study, we demonstrate how the deposition of small oligomeric (MoO) clusters-formed by the facile sublimation of MoO powders-leads to the self-assembly of locally ordered arrays of immobilized mono-oxo (MoO) species on anatase TiO(101).

Adsorption and reaction of methanol on FeO(001).

The interaction of methanol with iron oxide surfaces is of interest due to its potential in hydrogen storage and from a fundamental perspective as a chemical probe of reactivity. We present here a study examining the adsorption and reaction of methanol on magnetite FeO(001) at cryogenic temperatures using a combination of temperature programmed desorption, x-ray photoelectron spectroscopy, and scanning tunneling microscopy. The methanol desorption profile from FeO(001) is complex, exhibiting peaks at 140 K, 173 K, 230 K, and 268 K, corresponding to the desorption of intact methanol, as well as peaks at 341 K and 495 K due to the reaction of methoxy intermediates.