An investigation of the physical structure of MCM-41 novel mesoporous materials using a corrugated pore structure model
Φόρτωση...
Ημερομηνία
Συγγραφείς
Salmas, C. E.
Stathopoulos, V. N.
Pomonis, P. J.
Rahiala, H.
Rosenholm, J. B.
Androutsopoulos, G. P.
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
Applied Catalysis a-General
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The preparation and pore structure characterization of MCM-41 materials with or without Al or Ti addition during synthesis are presented in this work. Such solids are intended for use as catalysts supports possessing advantageous pore structure, total acidity and thermal stability characteristics. BET surface areas up to 1483 m(2)/g were determined and compared with cumulative surface areas obtained by methods like the conventional Roberts' and the newly reported corrugated pore structure model-nitrogen (CPSM-nitrogen) [Ind. Eng. Chem. Res. I 39(2000) 3747; Ind. Eng. Chem. Res. II 39 (2000) 3764]. CPSM predictions are in perfect agreement with estimates obtained by the BET monolayer adsorption variant. Pore size distributions (PSDs) were deduced by using both the Roberts' and the CPSM methods. The superiority of the latter method was confirmed, since apart from the prediction of intrinsic PSDs, enabled the determination of tortuosity factors ranging ca. tau (CPSM) = 1-2.35, for the studied materials [Ind. Eng. Chem. Res. 40 (2000) 721]. These values are lower than those for traditional catalysts ca. tau = 3-10 [Mass Transfer in Heterogeneous Catalysis, 1970, p. 37] and reflect the ordered pore structure of MCM-41 solids. Addition of Al (i.e. Si/Al = 5) caused a PSD shift towards the micropore region (i.e. D(mean) shift from 3.28 to 2.10 nm) in contrast to Ti addition (i.e. Si/Ti = 5) that caused a PSD shift farther to the mesopore region (i.e. D(mean) shift from 3.28 to 23.74 nm). Lower additions of Al or Ti (i.e. Si/Al = 20 and Si/Ti = 10) caused a pore volume and surface area reduction but not a substantial shift of the intrinsic PSDs. (C) 2001 Elsevier Science B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
pore structure, nitrogen sorption, mcm-41, cpsm model, tortuosity, mercury porosimetry hysteresis, size distributions, sorption isotherms, adsorption, catalysts, nitrogen, penetration, tomography, prediction, diffusion
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000169790100004
http://ac.els-cdn.com/S0926860X01005208/1-s2.0-S0926860X01005208-main.pdf?_tid=7f545c1c1059978b742e0e3ea49911af&acdnat=1333036679_c43c36e1dde7063cf123e72080453563
http://ac.els-cdn.com/S0926860X01005208/1-s2.0-S0926860X01005208-main.pdf?_tid=7f545c1c1059978b742e0e3ea49911af&acdnat=1333036679_c43c36e1dde7063cf123e72080453563
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