De-Sintering Action of Phosphorus in Alumina-Aluminum Phosphates (Aap) Containing Transition-Metal Ions (M = Cr, Mn, Fe, Co, Ni, Cu, Zn)
Φόρτωση...
Ημερομηνία
Συγγραφείς
Petrakis, D. E.
Pomonis, P. J.
Sdoukos, A. T.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Royal Society of Chemistry
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of the Chemical Society-Faraday Transactions
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The de-sintering action of phosphorus added in different amounts to alumina containing 20% of a second cation M (M = Cr, Mn, Fe, Co, Ni, Cu, Zn) has been quantified from measurements of the surface areas of the solids. The solids were prepared by co-precipitation with NH3 from solutions containing calculated amounts of metal nitrates and phosphoric acid and by heating at 600-degrees-C. The atomic ratio of the elements in the obtained solids was Al : P : M = 100 : x : 20 where x = 0, 4.5, 9, 18, 36, 72 and 144. The surface areas of the solids were measured by the B.E.T. method. The results showed that the maximum de-sintering action of phosphorus, as estimated from the change of the surface area of the solids, appeared at x = 9. Thereafter the surface area decreased, at a different pace for each cation, and at x = 36 it returned to the original value at x = 0. Further addition of phosphorus decreased the surface area even further and x = 144 it fell almost to zero, depending on the second cation. The strongest sintering ability was exhibited by Cu and Mn and the smallest by Cr, Fe and Ni, with the rest occupying intermediate positions. An explanation of the results is attempted by taking into account the enthalpies of formation of the corresponding metal phosphates and aluminates formed in each case.
Περιγραφή
Λέξεις-κλειδιά
oxidation, catalysts, phase, support
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://A1991FE63400017
http://pubs.rsc.org/en/Content/ArticleLanding/1991/FT/ft9918700901
http://pubs.rsc.org/en/Content/ArticleLanding/1991/FT/ft9918700901
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας