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Prediction of stable clusters based on the jellium model is limited because of the usual assumption of their spherical symmetry. Here the authors propose a symmetry adapted orbital model by quantum chemistry calculations for the prediction of stable clusters with various shapes that obey a certain periodicity.

No substances with greater degrees of degeneracy than spherical atoms are known, due to geometrical limitations. In this work the authors combine density functional theory and tight-binding models to predict metal clusters with higher-fold degeneracies than spherical atoms, which are ascribed to dynamical symmetry.

Direct detection and characterisation of small materials are fundamental challenges in analytical chemistry. A particle composed of dozens of metallic atoms, a so-called subnano-particle (SNP), and a single-atom catalyst (SAC) are ultimate analysis targets in terms of size, and the topic is now attracting increasing attention as innovative frontier materials in catalysis science. However, characterisation techniques for the SNP and SAC adsorbed on substrates requires sophisticated and large-scale analytical facilities. Here we demonstrate the development of an ultrasensitive, laboratory-scale, vibrational spectroscopic technique to characterise SNPs and SACs. The fine design of nano-spatial local enhancement fields generated by the introduction of anisotropic stellate-shaped signal amplifiers expands the accessibility of small targets on substrates into evanescent electromagnetic fields, achieving not only the detection of isolated small targets but also revealing the effects of intermolecular/interatomic interactions within the subnano configuration under actual experimental conditions. Such a development of “in situ subnano spectroscopy” will facilitate a comprehensive understanding of subnano and SAC science.

The structures of inorganic clusters are commonly characterized by mass spectrometry (MS), but neutral sulfur clusters heavily fragment under MS conditions, preventing their exact mass determination. Here, the authors successfully perform MS on labile cyclic sulfur clusters by stabilizing them within ionic supramolecular capsules.

The electrochemical reduction of CO2 has been extensively studied over the past decades. Nevertheless, this topic has been tackled so far only by using a very fundamental approach and mostly by trying to improve kinetics and selectivities toward specific products in half-cell configurations and liquid-based electrolytes. The main drawback of this approach is that, due to the low solubility of CO2 in water, the maximum CO2 reduction current which could be drawn falls in the range of 0.01–0.02 A cm–2. This is at least an order of magnitude lower current density than the requirement to make CO2-electrolysis a technically and economically feasible option for transformation of CO2 into chemical feedstock or fuel thereby closing the CO2 cycle. This work attempts to give a short overview on the status of electrochemical CO2 reduction with respect to challenges at the electrolysis cell as well as at the catalyst level. We will critically discuss possible pathways to increase both operating current density and conversion efficiency in order to close the gap with established energy conversion technologies.

Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), one of the application modes of surface-enhanced Raman spectroscopy (SERS), shows wide applicability in the materials and morphology of substrate being examined, and thus, is a powerful analytic technique that allows in situ/operando measurements at a solid-liquid interface, acquiring intrinsic vibrational spectra (fingerprint information) of materials at a molecular scale. This article provides an overview of the development of Raman spectroscopy suitable for in situ/operando interfacial analysis and introduces some recent technical developments of the amplifiers in SHINERS techniques. [ABSTRACT FROM AUTHOR]

The methanol oxidation on a hydroxylated Pt (Pt(111)–OH) surface has been investigated by means of infrared reflection absorption spectroscopy (IRAS) in ultra-high vacuum (UHV) and in acidic solution. The Pt(111)–OH surface in UHV was prepared by introducing water molecules on a Pt(111)–(2×2)–O surface and annealed at temperature higher than 160 K. Methanol was then, introduced to the Pt(111)–OH surface to show the dependence of the reaction intermediate on the annealing temperature. At an annealing temperature below 160 K, IR bands assignable to methanol overlayer were observed and no detectable intermediates, such as CO, formaldehyde and formate, were formed, suggesting that methanol molecules remain stable on Pt(111) surface without dissociation at this temperature region. At an annealing temperature above 160 K, on the other hand, CO and formate were observed. In addition, the oxidation of CO on Pt(111)–OH showed no sign of formate formation, indicating that formate is not derived from CO, but from a direct oxidation of methanol. Methanol oxidation was carried out in 0.1 mol dm−3 HClO4 solution on Pt(111) with a flow cell configuration and showed the formation of formate. These results indicate that the formate is the dominant non-CO intermediate both in UHV and in acidic solution, and the preadsorbed oxygen-containing species, in particular OH adsorbates, on Pt(111) surface plays a very important role in the formate formation process in methanol oxidation reaction. [ABSTRACT FROM AUTHOR]

Ethylene adsorption and oxidation on platinum electrodes have been investigated in acidic solution by means of cyclic voltammetry and in situ infrared spectroscopy. Ethylene oxidation is a surface structure-sensitive reaction being Pt(111) the only active electrode surface at potentials below surface oxidation. In situ infrared reflection absorption spectroscopy (IRRAS) allows to identify the products formed during the adsorption and oxidation of ethylene. Vinylidene species were detected as oxidized adsorbates coming from ethylene and the only oxygen-containing species observed were on-top adsorbed CO and dissolved CO2 that is the final oxidation product. A potential dependent equilibrium for transformation between two different adsorption configurations of adsorbed vinylidene, μ3-η2-C=CH2 and μ-C=CH2, has been observed. [Copyright &y& Elsevier]