Peer-Reviewed Journal Details
Mandatory Fields
O'Mahony, L; Sutton, D; Hodnett, BK
2004
July
Catalysis Today
In situ X-ray diffraction studies of the crystallization of VOHPO4 center dot 0.5H(2)O
Published
()
Optional Fields
in situ X-ray diffraction crystallization VPO BUTANE SELECTIVE OXIDATION VANADYL PYROPHOSPHATE MALEIC-ANHYDRIDE ACTIVE-SITE CATALYSTS FACILITY
91-2
185
189
Time resolved in situ X-ray diffraction was used to study the formation of vanadyl hydrogen phosphate hemihydrate (VOHPO4.0.5H(2)O) in organic media. This technique has identified a new phase at early synthesis times (less than 300 s) at a d-spacing of 7.5 and 3.1 Angstrom. The feature at 7.5 Angstrom shifted to 6.7 Angstrom during the first 20 min of synthesis and this phase collapsed as VOHPO4.0.5H(2)O formed. Thin symmetrical platelets of 10 mum x 10 mum dimensions were observed when samples were recovered after short synthesis times. Energy dispersive X-ray analysis indicated that these platelets contained vanadium and phosphorus. The platelets appeared to delaminate possibly associated with the strain generated when the d-spacing shifted from 7.5 to 6.7 Angstrom, from which growth of the VOHPO4.0.5H(2)O into the familiar rosette morphology occurs. (C) 2004 Elsevier B.V. All rights reserved.
0920-5861
10.1016/j.cattod.2004.03.031
Grant Details