C. Ferragina

Bio: C. Ferragina is an academic researcher from Sapienza University of Rome. The author has contributed to research in topics: Zirconium phosphate & Intercalation (chemistry). The author has an hindex of 11, co-authored 37 publications receiving 440 citations.

Characterisation and electronic properties of some inorganic ion exchangers of the zirconium phosphate type containig transition-metal ions

Abstract: A series of transition-metal-ion forms of crystalline zirconium phosphate of general formula ZrM(PO4)2·4H2O (M = ZnII, CuII, NiII, CoII, and MnII) has been characterised. The visible–near U.V. spectra of the copper, nickel, and cobalt species indicate the presence of an octahedral stereochemistry (tetragonally distorted in the case of CuII). The dehydration of the exchangers has been followed using thermal and X-ray powder techniques and electronic spectra. Magnetic-susceptibility measurements have also been used (where possible) to support structural assignment. Complete dehydration occurs only atca. 450 °C with a change in stereochemistry for the compounds of NiII and CoII. At higher temperature the layer structure is lost and the materials become double phosphates, MZr(PO4)2. Possible stereochemistries for the anhydrous forms are discussed.

From Microporous to Mesoporous Molecular-Sieve Materials and Their Use in Catalysis

Abstract: It is possible to say that zeolites are the most widely used catalysts in industry They are crystalline microporous materials which have become extremely successful as catalysts for oil refining, petrochemistry, and organic synthesis in the production of fine and speciality chemicals, particularly when dealing with molecules having kinetic diameters below 10 A The reason for their success in catalysis is related to the following specific features of these materials:1 (1) They have very high surface area and adsorption capacity (2) The adsorption properties of the zeolites can be controlled, and they can be varied from hydrophobic to hydrophilic type materials (3) Active sites, such as acid sites for instance, can be generated in the framework and their strength and concentration can be tailored for a particular application (4) The sizes of their channels and cavities are in the range typical for many molecules of interest (5-12 A), and the strong electric fields2 existing in those micropores together with an electronic confinement of the guest molecules3 are responsible for a preactivation of the reactants (5) Their intricate channel structure allows the zeolites to present different types of shape selectivity, ie, product, reactant, and transition state, which can be used to direct a given catalytic reaction toward the desired product avoiding undesired side reactions (6) All of these properties of zeolites, which are of paramount importance in catalysis and make them attractive choices for the types of processes listed above, are ultimately dependent on the thermal and hydrothermal stability of these materials In the case of zeolites, they can be activated to produce very stable materials not just resistant to heat and steam but also to chemical attacks Avelino Corma Canos was born in Moncofar, Spain, in 1951 He studied chemistry at the Universidad de Valencia (1967−1973) and received his PhD at the Universidad Complutense de Madrid in 1976 He became director of the Instituto de Tecnologia Quimica (UPV-CSIC) at the Universidad Politecnica de Valencia in 1990 His current research field is zeolites as catalysts, covering aspects of synthesis, characterization and reactivity in acid−base and redox catalysis A Corma has written about 250 articles on these subjects in international journals, three books, and a number of reviews and book chapters He is a member of the Editorial Board of Zeolites, Catalysis Review Science and Engineering, Catalysis Letters, Applied Catalysis, Journal of Molecular Catalysis, Research Trends, CaTTech, and Journal of the Chemical Society, Chemical Communications A Corma is coauthor of 20 patents, five of them being for commercial applications He has been awarded with the Dupont Award on new materials (1995), and the Spanish National Award “Leonardo Torres Quevedo” on Technology Research (1996) 2373 Chem Rev 1997, 97, 2373−2419

Atomically dispersed Fe3+ sites catalyze efficient CO2 electroreduction to CO.

Abstract: Currently, the most active electrocatalysts for the conversion of CO2 to CO are gold-based nanomaterials, whereas non-precious metal catalysts have shown low to modest activity. Here, we report a catalyst of dispersed single-atom iron sites that produces CO at an overpotential as low as 80 millivolts. Partial current density reaches 94 milliamperes per square centimeter at an overpotential of 340 millivolts. Operando x-ray absorption spectroscopy revealed the active sites to be discrete Fe3+ ions, coordinated to pyrrolic nitrogen (N) atoms of the N-doped carbon support, that maintain their +3 oxidation state during electrocatalysis, probably through electronic coupling to the conductive carbon support. Electrochemical data suggest that the Fe3+ sites derive their superior activity from faster CO2 adsorption and weaker CO absorption than that of conventional Fe2+ sites.