Search:
Computing and Library Services - delivering an inspiring information environment

Catalytic and adsorbent properties of solid acid catalysts studied by ammonia adsorption microcalorimetry

Savill-Jowitt, Claire (2007) Catalytic and adsorbent properties of solid acid catalysts studied by ammonia adsorption microcalorimetry. Doctoral thesis, University of Huddersfield.

[img]
Preview
PDF
Download (1740kB) | Preview

    Abstract

    Solid acid catalysts are becoming of great importance within the chemical industry and their
    acidity is of great interest, as this determines their application, plus many of their catalytic
    properties can also be directly related with their acidity. There has been a drive towards
    heterogeneous solid acid catalysts because of the environmental concerns with safe handling
    and disposal of mineral acid homogeneous catalysts such as H2SO4, and their separation from
    the product.
    Objectives of this work have been to study a range of solid acid catalysts and establish a
    relationship between catalyst strength, activity, and structure, and then identify the influence of
    solvent and type of reaction on the catalytic properties of the catalysts to be studied. Acid
    catalysts have been chosen to represent a cross-section of the various types of catalysts in use.
    The solid acid catalysts being investigated include sulfonated polystyrene ion exchange resins,
    acid activated clays, zeolites, and heteropoly acid (H3PW12O40) supported on carbon and
    mesoporous silica. Supported heteropoly acids have been prepared by Dr A Lapkin, University
    of Bath in the collaborative part of the project.
    Catalysts have been characterised in terms of their surface areas, pore diameters, pore volumes,
    and crystallinity from nitrogen adsorption, powder x-ray diffraction, cation exchange capacity,
    and elemental analysis. The acidity of these catalysts has been studied by NH3 adsorption
    microcalorimetry. NH3 is assumed to adsorb stoichiometrically on surface acid sites and the
    molar enthalpy of ammonia adsorption is assumed to reflect the strength of the acid sites. The
    catalytic activities of the catalysts have been measured using two Brønsted acid catalysed test
    reactions (rearrangement of α-pinene and the hydrolysis of ethyl acetate). The correlation
    between characterisation results and catalytic data has been examined with emphasis being
    placed on the relationship between acidity measurements and the reaction medium or solvent.
    Conclusions that can be drawn from this work are that NH3 adsorption microcalorimetry is a
    useful technique for studying surface acidity of solid acids and that it does allow for some
    correlation to be drawn between catalytic activity and acidity, with the aid of additional catalyst
    characterisation techniques.

    ▼ Jump to Download Statistics
    Item Type: Thesis (Doctoral)
    Additional Information: © The Author 2007
    Uncontrolled Keywords: solid acids ammonia adsorption microcalorimetry
    Subjects: Q Science > Q Science (General)
    Q Science > QD Chemistry
    Schools: School of Applied Sciences
    References:

    1 N. Besun, F. Ozkan, G. Gunduz, App. Catal. A:Gen., 224 (2002) 285-297.
    2 O. Akpolat, G. Gunduz, F. Ozkan, N. Besun, App. Catal. A:Gen., 265 (2004) 11-22.
    3 F. Ebmeyer, J. Mol. Struct. – Theochem., 582 (2002) 251-255.
    4 A.D. Newman, D.R. Brown, P. Siril, F. Lee, K. Wilson, Phys. Chem. Chem. Phys., 8 (2006) 2893-2902.
    5 Toshio Okuhara, Chem. Rev., 102 (2002) 3641-3666.
    6 A. Mitsutani, Catal. Today, 73 (2002) 57-63.
    7 M.N. Timofeeva, App. Catal. A-Gen., 256 (1-2) (2003) 19-35.
    8 M. Kimura, T. Nakato, T. Okuhara, Appl. Catal. A-Gen., 165 (1-2) (1997) 227-240.
    9 S. Namba, N. Hosonuma, T.J. Yashima, J. Catal., 72 (1981) 16-20.
    10 J. McMurray, “McMurray Organic Chemistry – 4th Edition”, Eds; Brooks/Cole (1995) p.828.
    11 M. Misono, I. Ono, G. Koyano, A. Aoshima, Pure Appl. Chem., 72 (7) (2000) p.1307.
    12 M. Misono, Catal. Rev. Sci. Eng., 29 (2-3) (1987) 269-321; 30 (2) (1988) 339-340.
    13 S. Koujout, D.R. Brown, Catal. Lett., 98 (4) (2004) 195-202.
    14 M. Misono, Chem. Commun., (2001) 1141-1152.
    15 I.V. Kozhevnikov, Russ. Chem. Rev., 56 (9) (1987) 811-825.
    16 T. Okuhara, N. Mizuno, M. Misono, Adv. Catal., 41 (1996) 113-252.
    17 J. Haber, K. Pamin, L. Matachowski, D. Mucha, App. Catal. A:Gen, 256 (2003) 141-152.
    18 M. Furuta, K. Sakata, M. Misono, Y. Yoneda, Chem. Lett., 1 (1979) 31-34.
    19 Y. Izumi, K. Urabe, Chem. Lett., (1981) 663-666.
    20 G.I. Kapustin, T.R. Brueva, A.L. Klyachko, M.N. Timofeeva, S.M. Kulikov, I.V. Kozhevnikov, Kinet.
    Katal., 31 (4) (1990) 1017-1020.
    21 I.V. Kozhevnikov, J. Mol. Catal. A:Chem., 114 (1-3) (1996) 287-298.
    22 J. Haber, K. Parmin, L. Matachowski, D. Mucho, Appl. Catal. A:Gen., 256 (2003) 141-252.
    23 http://en.wikipedia.org/wiki/Ionic_radius - accessed on 25.06.07.
    24 C. Volzone, O. Masini, N.A. Comelli, L.M. Grzona, E.N. Ponzi, M.I. Ponzi, Appl. Catal. A:Gen., 214
    (2001) 213-218.
    25 C.N. Rhodes, D.R. Brown, Catal. Lett., 24 (3-4) (1994) 285-291.
    26 G. Gunduz, R. Dimitrova, S. Yilmaz, L. Dimitrov, M. Spassova, J. Mol. Catal. A:Chem., 225 (2005) 253-
    258.
    27 A. Chakrabarti, M.M. Sharma, React. Polym., 20 (1993) 1-45.
    28 M. Hart, G. Fuller, D.R. Brown, C. Park et al., Catal. Lett., 72 (3-4) (2001) 135-139.

    Depositing User: Sara Taylor
    Date Deposited: 20 Dec 2007
    Last Modified: 28 Jul 2010 19:21
    URI: http://eprints.hud.ac.uk/id/eprint/420

    Document Downloads

    Downloader Countries

    More statistics for this item...

    Item control for Repository Staff only:

    View Item

    University of Huddersfield, Queensgate, Huddersfield, HD1 3DH Copyright and Disclaimer All rights reserved ©