Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 9 February 1996:
Vol. 271. no. 5250, pp. 799 - 802
DOI: 10.1126/science.271.5250.799
Prev | Table of Contents | Next

Reports

On the Nature of Water Bound to a Solid Acid Catalyst

L. Smith,  A. K. Cheetham (1),  R. E. Morris,  L. Marchese,  J. M. Thomas (1),  P. A. Wright,  J. Chen (1)

The nature of the species formed when water interacts with Brønsted acid sites in a microporous solid acid catalyst, HSAPO-34, was studied by powder neutron diffraction and infrared spectroscopy. Previous infrared and computational studies had failed to unambiguously establish whether water is protonated to form hydronium (H3O+) ions or is merely hydrogen-bonded to acid sites inside the zeolite. Our experiments clearly showed that both species are present: An H3O+ ion is found in the eight-ring channel of the zeolite and a second water molecule is hydrogen-bonded to an acid site on the six-ring.


L. Smith, A. K. Cheetham, R. E. Morris, Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
L. Marchese, Dipartimento di Chimica I.F.M., Università degli Studi di Torino, 10125-Torino, Italy.
J. M. Thomas, P. A. Wright, J. Chen, Royal Institution of Great Britain, 21 Albemarle Street, London W1X 4BS, UK.
(1) To whom correspondence should be addressed.

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)