Carlo Lamberti's research while affiliated with Southern Federal University and other places

Publications (11)

Article
Cu-SAPO-34 (Cu-CZC) and Fe-mordenite (Fe-MOR) and their mechanical mixture (50 : 50) have been exhaustively investigated by means of operando X-ray absorption spectroscopy under NH3-SCR conditions. Fe K-edge XANES and EXAFS analysis revealed similar Fe-speciation in both the pure Fe-MOR catalyst and the mechanical mixture after high-temperature pre...
Article
Everybody dreams to have X-ray eyes and discover the most invisible secrets of the world around us. X-rays can probe matter (depth resolved) down to atomic resolution, if relying on diffraction-based techniques. An X-ray diffraction pattern may contain information over many length scales (atomic structure, microstructure, mesostructure). This pecul...
Article
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The direct stepwise transformation of CH4 to CH3OH over Cu-exchanged zeolites has been an intensively researched reaction as it can provide a solution for the utilization of this abundant feedstock. Up to date a commercial process is far from realization, which is why an understanding of the Cu speciation in zeolites as a function of reaction condi...
Article
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We report a series of Pd K-edge and Pt L3-edge X-ray absorption spectra (XAS) collected in situ during thermal treatment of functionalized UiO-67-Pd and UiO-67-Pt metal-organic frameworks in inert and reducing atmospheres. We present raw synchrotron data from three subsequent experiments at different beamlines, normalized XAS spectra and k2-weighte...
Article
We report a complete experimental characterization of the surface Pt-hydride species on an industrial 5wt% Pt/Al2O3 catalyst (average particle size of 1.4 ± 0.4 nm) under different hydrogenation/dehydrogenation conditions. By combining Inelastic Neutron Scattering, FT-IR spectroscopy and synchronous DRIFT/XAS/MS, we identified n-fold coordinated Pt...
Article
Functionalization of metal-organic frameworks (MOFs) with noble metals is a promising way for producing new versatile catalysts that will combine the outstanding porosity and specific surface area of MOFs with high catalytic activity of metals. Here, we present a comparative study of two metal-organic frameworks with UiO-67 topology, functionalized...
Article
Full-text available
Treatment of MOF-5 with NbCl4(THF)2 in acetonitrile leads to incorporation of Nb(IV) centers in a fashion that diverges from the established cation metathesis reactivity of this iconic material. A combination of X-ray absorption spectroscopy analysis and reactivity studies altogether supported by density functional theory computational studies docu...
Article
Full-text available
We report the series of Pd K-edge X-ray absorption spectra collected during hydrogenation of ethylene with variable ethylene/hydrogen ratio over carbon supported palladium nanoparticles. The data presented in this article includes normalized X-ray absorption spectra, k ² -weighted oscillatory χ(k)functions extracted from the extended X-ray absorpti...
Article
The Cu-exchanged CHA zeolite (Cu-CHA) is a promising catalyst for the NH3-assisted selective catalytic reduction (NH3-SCR) of harmful nitrogen oxides (NOx, x = 1, 2), combining high hydrothermal stability with a good performance in the 200-550 °C range. Despite many recent breakthroughs in the molecular-scale understanding of this catalyst, several...
Article
This study investigates the impact of iodine, chlorine and bromine adsorption on the structure of bimetallic Co/Zn zeolitic imidazolate frameworks (ZIFs). The experimental Co and Zn K-edges XANES (X-ray Absorption Near Edge Structure) spectra of Zn0.5Co0.5C8H10N4 synthesized by microwave synthesis were measured before and after halogens treatment.
Article
Palladium nanoparticles (NPs) find numerous applications as catalysts for hydrogenation of hydrocarbons. Under reaction conditions, formation of palladium hydrides and carbides may occur, which affects the catalytic properties of the catalyst. Unlike pure hydride phase, whose phase diagram is well-studied, conditions of formation of palladium carbi...

Citations

... The choice of the radiation source to image a target depends on its properties (size, and composition). With X-rays, one can image objects in the µm to mm scale [66]. However, the imaging of thicker objects requires a higher energy radiation source. ...
... In a number of previous works, we have successfully applied in situ and operando X-ray absorption fine structure (XAFS) spectroscopy to follow the evolution of the catalyst under hydrogenation reaction conditions [32,33,36,38,[44][45][46]. The extended XAFS (EXAFS) spectra provide direct information on the local atomic structure (interatomic distances and coordination numbers) around the element of interest (averaged over all of its possible locations). ...
... Further inelastic scattering enables us to analyze the low-frequency vibration modes of H species on the catalyst. Thus, many investigations into H species on various metal catalysts and related materials have been carried out by using INS spectroscopy, e.g., H atoms on supported precious metal catalysts such as Pd/C [10,11], Pt/C [12][13][14], Au/CeO 2 [15], and Pt/Al 2 O 3 [16,17], as well as H atoms in Pd hydride [18,19], H atoms in carbonaceous species formed in catalysis [10], and H species on active carbon catalysts [20]. In our previous study, several bands were observed in INS spectra of alumina-supported platinum catalyst, Pt/Al 2 O 3 , and they were assigned to various kinds of Pt-H, Pt-H-Pt, Al-H, and AlO-H bonds with the aid of density functional theory (DFT) [17]. ...
... On the basis of the concentration plot of the principal components during the reduction at the Pt L III -edge (Figure 7a), the component D r rapidly decreased already at room temperature under the exposure to H 2 with the consequent increase of the A r component. By comparison with the references XANES spectra (Figure 7b), the D r spectrum visually resembled the Pt one with a characteristic shape and edge shifted to higher energy with respect to the Pt reference one, 60 to which the A r spectrum approached. From the FT of the EXAFS part (Table S3), the best fit of the D r EXAFS data confirmed the assignment to metallic Pt (CN 4.24 ± 0.6 at 2.8 Å) with a minor contribution of PtO (first shell CN 1.79 ± 0.0.2 at 2.0 Å) at the initial stage of the reduction, as already observed for the supported NCs after calcination. ...
... We can also observe the hyperfine coupling of niobium(IV) (Figure 11), with values close to the ones found in the literature. 13 The intense absorption peak, corresponding to the signal of an oxo group, verifies the existence of a Nb−O bond, in which the electron is delocalized with an equilibrium between Nb−O and Nb−O · . By performing Q-band experiments, we can observe a weak anisotropy of the g factor, indicating that the symmetry is higher ( Figure S5b). ...
... Several previous studies reported the formation of palladium carbides (Pd-C) during thermal hydrogenation of alkynes. 22,23 Indeed, our theoretical simulations suggest that atomic carbon is stable on the Pd surface with respect to propene (Fig 2B), but unstable compared to possible oxidation products, such as CO(ad) and subsequently formed CO 2 (g) at oxidising potentials. A full microkinetic model that could resolve this is beyond the scope of this paper, however, further insight into the surface state can be gained from our XAS data. ...
... Research Article C. 43 DRM catalysts with varied compositions, such as PdZrO 2 42 or NiFe-MgO, 44 have reported an initial induction period to form a beneficial carbon overlayer that promotes CO 2 reduction during DRM. Our findings are consistent with these evidences, where based on the time on stream study we observe an improvement in CO 2 conversion as a function of time. ...
... All in all, the relatively low SO 2 resistance limits the broader application of Cu-CHA in NH 3 -SCR. Except for the regeneration method reviewed above, it was reported that some reductants, such as NH 3 , C 3 H 6 , and n-C 12 H 26 , can achieve the removal of sulfate without heat treatment by changing the oxidation state of Cu [58][59][60]. Kumar et al. [46] reported that 1000 × 10 −6 C 3 H 6 can achieve the complete removal of sulfate in the oxidizing atmosphere. It was proposed that recovery is beneficial for the reduction in binding energy between sulfate and Cu. ...
... [83] Investigated the I 2 removal properties of the MOF-polymer composite beads, Cu-BTC@PES. [84] Investigated the I 2 capture properties of a number of Co/Zn-based bimetallic MOFs. [85] Synthesized via the facile phase inversion method the zirconium-based MOF and poly(vinylidene fluoride) (PVDF) composite beads for I 2 capture. ...