A kinetic and mechanistic study into the formation of the Cu-Cr layered double hydroxide

DOI: 10.1039/c3cp44339f

Authors: Gareth Williams (University College London (UCL)) , Alexander Clout (University College London (UCL)) , Jonathan Burley (University of Nottingham)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Chemistry Chemical Physics , VOL 15 , PAGES 8616-8628

State: Published (Approved)
Published: February 2013
Diamond Proposal Number(s): 7782

Abstract: The formation of the layered double hydroxide [Cu2Cr(OH)6]Cl·yH2O from the reaction between CuO and aqueous CrCl3·6H2O was explored using synchrotron X-ray diffraction and ex situ analyses. The use of hard X-rays permitted time-resolved in situ studies to be performed as the reaction proceeded under a range of conditions. Additional information was obtained from ex situ experiments in which aliquots of the reaction mixture were removed, quenched, and subsequently analysed by laboratory X-ray diffraction, IR, UV-visible, and atomic emission spectroscopies. On the basis of these data, it is proposed that the reaction involves three steps. First, the solid CuO starting material is hydrolysed to give Cu(OH)2 chains, releasing Cu2+ ions into solution. The Cu hydroxide chains subsequently condense with aqueous Cr3+ species, Cl? ions and water molecules to give a hydrated form of the LDH. This material then extrudes some water to form a phase with a reduced interlayer spacing.

Subject Areas: Chemistry


Instruments: I12-JEEP: Joint Engineering, Environmental and Processing

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