[Show abstract][Hide abstract] ABSTRACT: Three kinds of Al-pillared montmorillonite clay minerals (AlPMON) ion-exchanged with cobalt(II), nickel(II), or copper(II) ions were prepared (abbreviated as CoAlPMON, NiAlPMON, or CuAlPMON, respectively). For the 673-K- and 873-K-treated samples, carbon monoxide (CO) adsorption measurement was performed at room temperature under an atmosphere of low CO pressure. The 873-K-treated CuAlPMON sample exhibited more efficient adsorption properties for CO molecules, in comparison with both-temperatures-treated CoAlPMON and NiAlPMON samples and the 673-K-treated CuAlPMON sample. In addition, irreversibly adsorbed CO was present only on the CuAlPMON sample that had been treated at 873 K; the sites responsible for strong CO adsorption were formed in the sample after the pretreatment at the higher temperature.
No preview · Article · Oct 2007 · Journal of Colloid and Interface Science
[Show abstract][Hide abstract] ABSTRACT: Copper ion-exchanged montmorillonite clays, which had been prepared by ion exchange in an aqueous solution of CuCl(2) at a temperature above 323 K, exhibited the characteristic IR band in the region 3360-3310 cm(-1). No such bands were observed for the samples prepared by using different ion-exchange solutions and at different temperatures. From the spectroscopic observations, it was revealed that the ion-exchanged copper ions (Cu(2+)) are in the form of dimerized species by bridging two hydroxyls, [Cu(2+) <(OH(-)(2) > Cu(2+)], in montmorillonite.
No preview · Article · May 2007 · Journal of Colloid and Interface Science