654 research outputs found
Co-catalyst free ethene dimerization over Zr-based metal-organic framework (UiO-67) functionalized with Ni and bipyridine
Influence of Cu-speciation in mordenite on direct methane to methanol conversion: Multi-Technique characterization and comparison with NH3 selective catalytic reduction of NOx
PdZn/ZrO2+SAPO-34 bifunctional catalyst for CO2 conversion: Further insights by spectroscopic characterization
Experimental and Theoretical Evidence for the Promotional Effect of Acid Sites on the Diffusion of Alkenes through Small-Pore Zeolites
Cu- And Fe-speciation in a composite zeolite catalyst for selective catalytic reduction of NOx: insights fromoperandoXAS
Combining X-ray Diffraction and X-ray Absorption Spectroscopy to Unveil Zn Local Environment in Zn-Doped ZrO2Catalysts
<p>Zinc-doped zirconia catalytic properties, promising toward CO2 and CO hydrogenation, are commonly ascribed to the synergic interaction between Zn and Zr, yet an atomic-scale perspective on how this synergy is structurally realized remains elusive. In this work, to address this ongoing challenge, we deeply investigated the structure of three Zn-doped ZrO2 catalysts by combining powder X-ray diffraction (PXRD) and X-ray absorption spectroscopy (XAS). PXRD showed the complete formation of a tetragonal solid solution, undistinguishable by Rietveld refinement from the cubic polymorph. Fit of extended X-ray absorption fine structure (EXAFS) spectra at the Zr and Zn K-edges unveiled the presence of hexagonal/cubic ZnO nanoclusters embedded and chemically bonded to the tetragonal ZrO2 matrix. The concentration of Zn dopant was evaluated via both PXRD and EXAFS analysis. In situ EXAFS study of the catalyst during activation further confirmed the presence of a chemical interaction at ZnO/ZrO2 interface, most probably the active site toward CO2 hydrogenation. The ZnO cluster radius was found to be in the 11−13 Å range, using the Greegor and Lytle spherical model. Taken together, the results demonstrate how the combination of X-ray techniques probing both long-range and local structural properties could unlock an unprecedented level of understanding in mixed metal oxide catalysts.</p>
CO2 adsorption on different organo-modified SBA-15 silicas: A multidisciplinary study on the effects of basic surface groups
Unraveling the CO2 reaction mechanism in bio-based amino-acid ionic liquids by operando ATR-IR spectroscopy
Metal–Organic Frameworks in Italy: From synthesis and advanced characterization to theoretical modeling and applications
Effect of the preparation method on the catalytic properties of copper-containing zeolite Y applied for NH3-SCR-DeNO(x)
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