Publisher Summary This chapter discusses the characterization and reactivity of mononuclear oxygen species on oxide surfaces. Measurement of the electron paramagnetic resonance (EPR) parameters gives information which at the simplest level indicates the presence of a paramagnetic species but which can be sufficiently detailed to identify and characterize the adsorbed species. Measurements of the variation of the intensity of the signal with time can give kinetic data on reactions occurring at the surface. Although most of the EPR measurements have been carried out at low temperatures, there is evidence from the examples for some of the species that are stable at much higher temperatures and may play an important role in catalytic reactions.

Characterization and Reactivity of Molecular Oxygen Species on Oxide Surfaces

Oxides of the group VIb metals (Cr, Mo, W) and oxides of vanadium, rhenium, and niobium supported on a second high-surface-area metal oxide such as Al2O3, TiO2, Si02, ZrO2, and so forth are recognized as industrially important catalysts or catalyst precursors for various reactions [1–11], These materials frequently have been described as so-called monolayer catalysts based on a structural model which assumed spreading of the active oxide over the support surface. These catalysts have been investigated by a variety of techniques, conventional bulk sampling techniques as well as by surface-sensitive electron and ion spectroscopies, in an attempt to elucidate the nature of the catalyst surface species, and to study the coordination environment of the active metal center(s). Electronic spectroscopy gives rise to broad bands and the spectra are less informative than vibrational spectra. In addition, although techniques such as Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS...

Raman spectroscopy of monolayer-type oxide catalysts: Supported Mo oxides

High-performance inverted polymer solar cells (PSCs) with solution-processed titanium chelate TIPD as electron collecting layer are reported. The power conversion efficiency (PCE) of the inverted PSC with a-TIPD buffer layer with thermal annealing at 150 °C for 10 min reached 7.4% under the illumination of AM1.5, 100 mW/cm(2), which is increased by 16% in comparison with that (6.4%) of the device in the conventional structure. The PCE of 7.4% is the highest among the inverted PSCs reported so far in the literature.

High‐Performance Inverted Polymer Solar Cells with Solution‐Processed Titanium Chelate as Electron‐Collecting Layer on ITO Electrode

Molybdenum oxide can exhibit pronounced photochromism and thus might act as an excellent photonic material for a number of technical applications. In the early stage of the research, the attention was focused mainly on the (band) structure, photochromic mechanism and the behavior of the oxide. Later, many investigations were carried out on the factors that might influence the photochromic performance. At the same time, the photochromic response has been extended from UV light to visible light. In this review, the progress in all of these areas will be reviewed thoroughly.

Photochromism of molybdenum oxide

The formation of Si–O–defect groups due to the incorporation of Ti in the framework of zeolites is evidenced by means of solid-state tetraethylammonium (TEA) cation exchange; a new assignment for the infrared (IR) band in both β-Ti and TS-1 is presented.

R. S. Nyholm

Papers

713. The stretching frequencies of metal–oxygen double bonds