Controlled Modulation of Mesoporosities in Metal (M=Al, Fe) Phosphate Solids
Φόρτωση...
Ημερομηνία
Συγγραφείς
Petrakis, D. E.
Hudson, M. J.
Sdoukos, A. T.
Pomonis, P. J.
Bakas, T.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Colloids and Surfaces a-Physicochemical and Engineering Aspects
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Mesoporous solids which posses average pore diameters between 7 and 20 nm, depending on the composition, have been prepared. The solids have the general formula Al100P(x)M20 where M = Al or Fe, and x = 0, 4.5, 9, 18, 36, 72 or 144. The initial addition of phosphorus as phosphate transforms the originally crystalline oxide/oxides into amorphous solids. These amorphous materials posses a narrow pore size distribution: 80-90% of the pores lie within 1-2 nm of the average pore diameter. Subsequent incremental amounts of phosphorus transform the material into a crystalline solid whilst the pore size distribution becomes much wider and the maximum moves towards larger pore diameters. Substitution of 20% of the aluminium by iron results, at a low phosphorus content, in pores with smaller pore volumes and smaller surface areas. The data in the dV(p)/dD(p) = f(D(p)) graphs, where V(p) is the incremental pore volume and D(p) is the average pore diameter, can be approximated using an admixture of Gaussian and Lorentzian curves. For low phosphorus contents the dV(p)/dD(p) = f(D(p)) curves have a mainly Gaussian profile but the gradual addition of phosphorus transforms them to Lorentzian-type curves. An attempt to approximate the histograms dV(p) = f(D(p)) with the minimum number of distribution curves made up of the corresponding Gaussian and Lorentzian components indicates that each successive addition of phosphorus creates a dominant new pore component at a larger pore diameter. At the same time, the components at smaller pore diameters are diminished and eventually disappear as more phosphorus is added.
Περιγραφή
Λέξεις-κλειδιά
gaussian-lorentzian profiles, mesoporous phosphates, pore size distribution, catalytic activity, aluminum phosphates, oxide, texture, decomposition, phosphorus, aap
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://A1994PM32200008
http://ac.els-cdn.com/0927775794029113/1-s2.0-0927775794029113-main.pdf?_tid=3a3088c8f916b44a39bdcf27f0991b0b&acdnat=1333035596_50cd31e0220431c8c9020d50cc279d7b
http://ac.els-cdn.com/0927775794029113/1-s2.0-0927775794029113-main.pdf?_tid=3a3088c8f916b44a39bdcf27f0991b0b&acdnat=1333035596_50cd31e0220431c8c9020d50cc279d7b
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