A5074098435- Catalytic Processes in Materials Science
- X-ray Diffraction in Crystallography
- Metal-Organic Frameworks: Synthesis and Applications
- Catalysis and Oxidation Reactions
- Crystallization and Solubility Studies
- Machine Learning in Materials Science
- X-ray Spectroscopy and Fluorescence Analysis
- Catalysts for Methane Reforming
- Advanced Chemical Physics Studies
- Lanthanide and Transition Metal Complexes
- Magnetism in coordination complexes
- Nanomaterials for catalytic reactions
- Nanocluster Synthesis and Applications
- Carbon dioxide utilization in catalysis
- Zeolite Catalysis and Synthesis
- Radioactive element chemistry and processing
- Covalent Organic Framework Applications
- Catalysis and Hydrodesulfurization Studies
- Ammonia Synthesis and Nitrogen Reduction
- Electron and X-Ray Spectroscopy Techniques
- Crystallography and molecular interactions
- Hydrogen Storage and Materials
- Advanced Photocatalysis Techniques
- Thermal and Kinetic Analysis
- Polyoxometalates: Synthesis and Applications
European Synchrotron Radiation Facility
2017-2025
University of Turin
2013-2021
Southern Federal University
2013-2021
European Science Foundation
2021
National Interuniversity Consortium of Materials Science and Technology
2014-2016
Institute of Management Business and Law
2016
A series of nine Ce(<sc>iv</sc>)-based metal organic frameworks with the UiO-66 structure containing linker molecules different sizes and functionalities were obtained under mild synthesis conditions short reaction times.
For the first time, standard and fast selective catalytic reduction (SCR) of NO by NH3 are described in a complete cycle that is able to produce correct stoichiometry while allowing adsorption desorption stable molecules only. The SCR reaction coupling activation O2 with reaction, enabled release NO2. According scheme, can be divided into an oxidation catalyst + NH3; these steps together constitute cycle. Furthermore, both required reduction, finally, or NO2 leads same state catalyst. These...
Cu-SSZ-13 is a highly active NH3-SCR catalyst for the abatement of harmful nitrogen oxides (NO x , = 1, 2) from exhausts lean-burn engines. The study Cu-speciation occurring upon thermal dehydration key step understanding enhanced catalytic properties this material and identifying SCR sites their redox capability. Herein, we combined FTIR, X-ray absorption (XAS) emission (XES) spectroscopies with DFT computational analysis to elucidate nature location most abundant Cu in activated catalyst....
Cu-exchanged zeolites possess active sites that are able to cleave the C–H bond of methane at temperatures ≤200 °C, enabling its selective partial oxidation methanol. Herein we explore this process over Cu-SSZ-13 materials. We combine activity tests and X-ray absorption spectroscopy (XAS) thoroughly investigate influence reaction parameters material elemental composition on productivity Cu speciation during key steps. find CuII moieties responsible for conversion formed in presence O2 high...
The small-pore Cu-CHA zeolite is today the object of intensive research efforts to rationalize its outstanding performance in NH3-assisted selective catalytic reduction (SCR) harmful nitrogen oxides and unveil SCR mechanism. Herein we exploit operando X-ray spectroscopies monitor catalyst action during NH3-SCR 150–400 °C range, targeting Cu oxidation state, mobility, preferential N or O ligation as a function reaction temperature. By combining XANES, EXAFS, vtc-XES, unambiguously identify...
In the typical NH3-SCR temperature range (100-500 °C), ammonia is one of main adsorbed species on acidic sites Cu-SSZ-13 catalyst. Therefore, study at high a key step for understanding its role in catalytic cycle. We employed different spectroscopic techniques to investigate nature complexes occurring upon NH3 interaction. particular, FTIR spectroscopy revealed formation species, that is, (i) bonded copper centers, (ii) Brønsted sites, and (iii) NH4(+)·nNH3 associations. XANES XES allowed us...
The direct conversion of methane to methanol (MTM) is a reaction that has the potential disrupt great part synthesis gas-derived chemical industry. However, despite many decades research, active enough catalysts and suitable processes for industrial application are still not available. Recently, several copper-exchanged zeolites have shown considerable activity selectivity in MTM reaction. Understanding nature site these materials essential any further development field. Herein, we apply...
Accurate modeling of the X-ray absorption near-edge spectra (XANES) is required to unravel local structure metal sites in complex systems and their structural changes upon chemical or light stimuli. Two relevant examples are reported here concerning following: (i) effect molecular adsorption on 3d metals hosted inside metal-organic frameworks (ii) induced dynamics spin crossover complexes. In both cases, amount models for simulation can reach a hundred, depending number parameters. Thus,...
The small pore Cu-CHA zeolite is attracting increasing attention as a versatile platform to design novel single-site catalysts for deNO x applications and the direct conversion of methane methanol. Understanding at atomic scale how catalyst composition influences Cu-species formed during thermal activation key step unveil relevant composition-activity relationships. Herein, we explore by in situ XAS impact on temperature-dependent Cu-speciation reducibility. Advanced multivariate analysis...
The NH3-mediated selective catalytic reduction (NH3-SCR) of NOx over Cu-ion-exchanged chabazite (Cu-CHA) catalysts is the basis technology for abatement from diesel vehicles. A crucial step in this reaction activation oxygen. Under conditions low-temperature NH3-SCR, oxygen only reacts with CuI ions, which are present as mobile diamine complexes [CuI(NH3)2]+. To determine structure and reactivity species formed by oxidation these at 200 °C, we have followed reaction, using a Cu-CHA catalyst...
The development of an efficient photocatalyst for C2 product formation from CO2 is urgent importance toward the deployment solar-fuel production. Here, we report a template-free, cost-effective synthetic strategy to develop carbazole-derived porous organic polymer (POP)-based composite catalyst. catalyst comprised In2.77S4 and (POP) held together by induced-polarity-driven electrostatic interaction. Utilizing synergy catalytically active In centers light-harvesting POPs, showed 98.9%...
While titanium-based metal-organic frameworks (MOFs) have been widely studied for their (photo)catalytic potential, only a few TiIV MOFs reported owing to the high reactivity of employed titanium precursors. The synthesis COK-47 is now presented, first Ti carboxylate MOF based on sheets O6 octahedra, which can be synthesized with range different linkers. as an inherently defective nanoparticulate material, rendering it highly efficient catalyst oxidation thiophenes. Its structure was...
We present three methods of the synthesis zirconium metal–organic framework UiO-67 functionalized with platinum bipyridine coordination complexes (bpydcPtIICl2 and bpydcPtIVCl4) acting as linkers in MOF framework. These Pt can be reduced to bpydcPt0 under flow H2 gas 600–700 K range, probed by a sophisticated parametric refinement situ EXAFS data. IR spectroscopy testifies high coordinative unsaturation centers, able form bpydcPt0(CO)2 dicarbonyl upon CO adsorption. The large pore size...
Extreme toxicity, corrosiveness, and volatility pose serious challenges for the safe storage transportation of elemental chlorine bromine, which play critical roles in chemical industry. Solid materials capable forming stable nonvolatile compounds upon reaction with halogens may partially mitigate these by allowing halogen release on demand. Here we demonstrate that quantitatively oxidize coordinatively unsaturated Co(II) ions a robust azolate metal-organic framework (MOF) to produce...
The introduction of Ce4+ as a structural cation has been shown to be promising route redox active metal-organic frameworks (MOFs). However, the mechanism by which these MOFs act catalysts remains unclear. Herein, we present detailed study site in [Ce6 O4 (OH)4 ]-based such Ce-UiO-66, involved aerobic oxidation benzyl alcohol, chosen model reaction. X-ray absorption spectroscopy (XAS) data confirm reduction up one ion per Ce6 cluster with corresponding outwards radial shift due larger radius...
Metal-organic frameworks of general composition [M6(OH)4(O)4(PDC)6-x(Cl)2x(H2O)2x] with M = Zr, Ce, Hf; PDC2- 2,5-pyridinedicarboxylate and 0 ≤ x 2 were obtained under reflux using formic, nitric or acetic acid as an additive. Rietveld refinements carried out a fixed occupancy the linker molecules according to results thermogravimetric measurements confirmed that MOFs crystallize in UiO-66 type structure demonstrate structural models describe data well. Further characterization was by NMR...
We report a synthetic strategy to link titanium-oxo (Ti-oxo) clusters into metal-organic framework (MOF) glasses with high porosity though the carboxylate linkage. A new series of MOF was synthesized by evaporation solution containing Ti-oxo Ti
Hydride formation in palladium nanoparticles was studied by Pd K-edge X-ray absorption spectroscopy both the near-edge (XANES) and extended (EXAFS) regions diffraction (XRD) situ as a function of temperature hydrogen pressure. In contrast to EXAFS XRD, which probe Pd–Pd interatomic distance changes, direct effect concentration on electronic structure is observed intensities peak positions XANES region. By using theoretical simulations, we propose simple analysis based changes relative...
Bimetallic Ce/Zr-UiO-66 metal-organic frameworks (MOFs) proved to be promising materials for various catalytic redox applications, representing, together with other bimetallic MOFs, a new generation of porous structures. However, no direct proof the presence both metals in single cornerstone UiO-type MOFs was reported so far. Employing element-selective X-ray absorption spectroscopy techniques herein, we demonstrate, first time, that our synthesis route allows obtaining desired Ce content...
We report an in situ, temperature and H2 pressure-dependent, characterization of (2.6 ± 0.4) nm palladium nanoparticles supported on active carbon during the process hydride phase formation. For first time core–shell structure is highlighted single-component particles basis a different atomic electronic configurations inner "core" surface "shell" regions. The these examined by combined X-ray powder diffraction (XRPD), which sensitive to crystalline core region nanoparticles, shell analysis...