The layered double hydroxides (LDHs) are nano-ordered layered compounds and well known for their ability to intercalate anionic compounds. Most LDH is prepared conventionally only with divalent and trivalent cations. In this study, Co-Zr-Si LDH, consisting of divalent. tetravalent, and tetravalent cations, was prepared and reacted with monocarboxylic acids at room temperature. The Co-Zr-Si LDH and intercalated compounds have been characterized by energy-dispersive X-ray spectrometry. X-ray powder diffraction, IR spectra, thermal analysis, and scanning electron microscopy (SEM). The insertion of cyanate and carbonate anions into LDH was confirmed by IR spectra. XRD patterns of the prepared Co-Zr-Si LDH showed that the interlayer spacing of the LDH is 0.78 mu. The spacing is similar to that of usual LDH in which chloride, carbonate, or bromide anion is the guest. SEM images showed that Co-Zr-Si LDH can exist as plate-like or fibrous structures. (c) 2005 Elsevier Inc. All rights reserved.