Valence State Study of Supported Ruthenium Ru/MgO Catalysts

Abstract

Ru/MgO catalysts have been studied by X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction. Significant part (up to 75%) of supported metal was found to exist in an X-ray amorphous state with the particle size smaller than 3 nm. The analysis of the spectra belonging to the core levels and the valence zone showed that the X-ray amorphous part of ruthenium may exist in the forms of both metal and oxide clusters and nanoparticles depending on the ruthenium precursor.

Infrared Spectroscopic Study of α-Cyano-4-hydroxycinnamic Acid on Nanocrystalline TiO2Surfaces: Anchoring of Metal-Free Organic Dyes at Photoanodes in Dye-Sensitized Solar Cells

“…7 In addition temperature-dependent interfacial vibrational spectroscopic tools can provide information on the energetics or phase transition of adsorbates on surfaces. [8][9][10] Despite several spectroscopic reports on Ruthenim (II) complexes, [11][12][13][14] there has not been either investigation on the spectroscopic study or the thermal degradation and the resulting change in molecular architecture in detail for a cyanoacrylic acid film fabricated on the TiO2 surfaces to the best of our knowledge. In this present work, temperature-dependent diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy was applied to understand the nature of adsorption and structural change of α-cyano-4-hydroxycinnamic acid (CHCA) on the TiO2 surfaces.…”

A comprehensive study of indole catalytic hydrodenitrogenation under hydrothermal conditions

“…Considering the overlap between the Ru 3d 3/2 peak and the C 1s peak at about 284.6 eV, the Ru 3d 5/2 peak at about 280 eV was employed to analyze the chemical state of surface Ru. Within this region, the peak at 280.1 eV is attributed to metallic Ru, 41 and the other two spin‐orbit splitting peaks observed at 280.5 and 285.5 eV are assigned to ruthenium oxide (RuO 2 ) 42 . Although the severe overlap in this range does not allow a reliable integration of the peak areas for metallic and oxidized Ru, the area for Ru ° in the used catalyst is noticeably larger than that in the fresh catalyst, as shown in Figure 14E.…”

“…As shown in Figure 9A . 42 Although the severe overlap in this range does not allow a reliable integration of the peak areas for metallic and oxidized Ru, the area for Ru in the used catalyst is noticeably larger than that in the fresh catalyst, as shown in structure, implying that there was a strong electronic interaction between the Ni and Ru during the hydrothermal reaction. [43][44][45] The XRD patterns of the fresh and used Ni-Ru catalysts are shown in…”

“…Considering the overlap between the Ru 3d 3/2 peak and the C 1s peak at about 284.6 eV, the Ru 3d 5/2 peak at about 280 eV was employed to analyze the chemical state of surface Ru. Within this region, the peak at 280.1 eV is attributed to metallic Ru,41 and the other two spin-orbit splitting peaks observed at 280.5 and 285.5 eV are assigned to ruthenium oxide (RuO 2 ) 42. Although…”

The effect of Ag as a promoter for Ru/CeO2 catalysts in ammonia synthesis

“…Lots of papers have proven that the interface between Ru and reduced support (such as CeO 2−x , BaZrO 3−x , BaCeO 3−x and Ta 2 O 3−x ) was an efficient site for activation of N 2 [19,26,36,37]. Most recent literature also thought the presence the interface existing in Ru and reduced promoter (such as CsO 2+x and BaO 1+x ) was the main active sites for ammonia synthesis in Ba-Ru/AC, Cs-Ru/AC and Cs-Ru/MgO systems [38][39][40]. Obviously, the nature of the Ru/support or Ru/promoter interface is a major control factor of ammonia synthesis.…”