Comparative-Study of the Solid-State and Catalytic Properties of La2-Xsrxnio4-Lambda Perovskites (X = 0.00-1.50) Prepared by the Nitrate and Citrate Methods
Φόρτωση...
Ημερομηνία
Συγγραφείς
Ladavos, A. K.
Pomonis, P. J.
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
Perovskites of the form La2-xSrxNiO4-lambda (x = 0.00, 0.25, 0.50, 0.75, 1.00, 1.25 and 1.50) have been prepared using both the nitrate and citrate methods. The solids obtained were examined by X-ray diffraction at various temperatures to examine the development of their crystal structure. Surface area determinations showed that the citrate method yields solids with surface areas that are on average three times as high as those of the nitrate species, a result that is due to the lower temperature required for the formation of the perovskite phase in the former case. Iodometric determination of the nickel oxidation state showed that this is similar for the two sets of samples in the range 0.00 < x < 0.75 but appreciably higher for nitrate solids for x > 0.75. These results are corroborated by magnetic measurements. The catalytic activity for both sets of solids, probed by N2O decomposition, increases from x = 0.00 up to x = 0.75 - 1.00 if measured per unit mass, but up to 1.25 if measured per unit area of the solids. A comparison of the catalytic activity per unit mass for the two series indicates that citrate solids are about three times more active than the nitrate ones. This effect can be attributed to the higher surface area of the citrate solids. Nevertheless, the comparison per unit surface area shows that the citrate solids are still twice as active as the nitrates. Both series show a unique dependence of activity on oxygen deficiencies. Kinetic analysis of the catalytic results showed that this last factor alters the kinetics of the surface reaction and the apparent activation energies, a fact which is reflected in the reaction rates.
Περιγραφή
Λέξεις-κλειδιά
n2o decomposition, oxide lacoo3, adsorption, oxidation, kinetics, la2nio4, surface, alumina, ions, co
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://A1991GK45600031
http://pubs.rsc.org/en/Content/ArticleLanding/1991/FT/ft9918703291
http://pubs.rsc.org/en/Content/ArticleLanding/1991/FT/ft9918703291
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