
Restructuring highly electron-deficient metal-metal oxides for ... - Nature
2021年9月28日 · Herein, we introduce electron-deficient metal on semiconducting metal oxides-consisting of Ir (Rh, Au, Ru)-MoO 3 embedded by graphitic carbon layers (IMO) using an electrospinning method. We...
The modification of MoO3 nanoparticles supported on ... - Springer
2007年10月17日 · A detailed XAFS analysis reveals that at low Mo contents, the metastable hexagonal modification of MoO3 is formed despite the high calcination temperature of 500 °C. It is highly likely that the nanosize of the particles and the interaction between MoO3 and SBA-15 stabilize the metastable modification of the material.
Time-Resolved XAS Investigation of the Reduction/Oxidation of MoO3…
2000年4月1日 · Principal component analysis of Mo K-near-edge (XANES) spectra of reduction—oxidation cycles identified two constituent phases, namely MoO 2 and MoO 3. No intermediate was required to describe the experimental XANES spectra, indicating a rapid transition from the MoO 3 to the MoO 2 structure without the detection of intermediates.
Formation of bronzes during temperature-programmed reduction of MoO3 ...
2001年5月1日 · At a heating rate of 5 K/min, the formation of a more disordered bronze (H x MoO 3 with x ∼0.07) prior to the detection of the product phase MoO 2 was observed by in situ XAFS. In both studies, the consumption of the bronze was found prior to the complete reduction of …
In Situ XAS and XRD Studies on the Formation of Mo Suboxides …
2000年6月20日 · Reduction of MoO 3 with hydrogen (5−100 vol %) in the temperature range from 573 to 823 K was studied by in situ X-ray diffraction and X-ray absorption spectroscopy. The experiments performed focused on elucidating phase composition and evolution with time under isothermal as well as temperature-programmed reduction conditions.
Polarization-Dependent EXAFS Measurements of an α
We observed the polarization-dependent XAFS of an α-MoO3 single crystal. Polarization-dependent XANES spectra change with the polarization direction and the 1s → 4d pre-edge peak is shown to be a good indicator for the Mo=O (double bond oxygen) bond direction.
In situ XAFS study of phase transitions and hydrogen intercalation …
1995年3月1日 · In situ XAFS measurements at the Mo K and W La edges in HyMoxW~-xO3 compounds, performed at different hydrogen intercalation level and temperatures (from RT to 500), allowed us to determine the rearrangement in the first and second coordination shells of Mo and W cations during phase transitions.
With respect to a redox mechanism for the partial oxidation of propene on MoO 3, three stages are distinguished. (i) At temperatures below ~ 600 K the participation of oxygen from the MoO bulk is negligible. (ii) At temperatures between ~ 600 K and ~ 700 K oxygen vacancy. diffusion in the bulk is sufficient to make a redox mechanism feasible.
XAFS analysis of MoO 3/MgO catalysts-effects of loading Kenta SHIMURA, Saburo HOSOKAWA, Seiichiro IMAMURA, Hiroyoshi KANAI* Department of Chemistry, Kyoto Institute of Technology, Kyoto 606-8585, Japan Introduction A hard-to-epoxidize olefin, allyl acetate, was success- fully epoxidized with t-butyl hydroperoxide over MoO 3 / MgO catalysts[1].
Solid-state kinetics from time-resolved in situ XAFS ... - PubMed
2001年3月1日 · The reduction of MoO3 with hydrogen was studied by in situ X-ray absorption spectroscopy. The experiments performed focused on elucidating phase composition and evolution with time under isothermal reduction conditions. From temperature programmed experiments short-range structural details about the …