Structure of polynuclear palladium(II) hydroxocomplexes and the mechanism of their adsorption by carbon materials

The hydrolysis and precipitation of Pd(II) in 0.6molkg−1 NaCl: A potentiometric, spectrophotometric, and EXAFS study

“…Previous TEM, NMR and SAXS work by Troitskii et al (1993Troitskii et al ( , 1995Troitskii et al ( , 1996 in fact provided strong evidence for the formation of nano-size (15-40 Å ) hydrolysed palladium particles in aqueous solutions, as it will be discussed further in the following sections.…”

“…Partially hydrolyzed Pd(II) species can crosslink and form larger polymeric/polynuclear units that are stable as coiled [Pd(OH) 2 ] n chains of about 20 Å in diameter (Troitskii et al, 1993(Troitskii et al, , 1995(Troitskii et al, , 1996. Evidence for such particles was provided by Transmission Electron 0016-7037/$ -see front matter Published by Elsevier Ltd.…”

“…Palladium(II) is one of the most hydrolysable metal ions (Baes and Mesmer, 1976) and its hydrolysis products have consequently been studied under a variety of conditions (Wyatt, 1966;Izatt et al, 1967;Kazakova and Ptitsyn, 1967;Nabivanets and Kalabina, 1970;Rund, 1970;Milić and Bugarčić, 1984;Mountain and Wood, 1988;Kump and Byrne, 1989;Wood et al, 1989Wood et al, , 1992Wood, 1991;Byrne and Kump, 1993;Tait and Janecky, 1993;Tait et al, 1991;Troitskii et al, 1993Troitskii et al, , 1995Troitskii et al, , 1996Dressick et al, 1994;Didillon et al, 1998;van Middlesworth and Wood, 1999;Byrne and Yao, 2000;Cosden and Byrne, 2003). Partially hydrolyzed Pd(II) species can crosslink and form larger polymeric/polynuclear units that are stable as coiled [Pd(OH) 2 ] n chains of about 20 Å in diameter (Troitskii et al, 1993(Troitskii et al, , 1995(Troitskii et al, , 1996.…”

“…/j.gca.2007 Microcopy (TEM), Small Angle X-ray Scattering (SAXS), Nuclear Magnetic Resonance (NMR) and Extented X-ray Absorption Fine Structure spectroscopy (EXAFS) measurements. These species can further condense, upon drying, to palladium oxide particles that are typically no more than 15-40 Å in diameter (Troitskii et al, 1996;Didillon et al, 1998). They can also occur as mixed chloride-hydroxide species in chloride-rich solutions, as first shown by Wyatt (1966) (Pd(OH) 1.6 Cl 0.4 ) and later by Byrne and Yao (2000) (Pd(OH) 1.73 Cl 0.27 ), and control the solubility of Pd(II) under these conditions.…”

“…The aqueous speciation of palladium(II) is considerable interest for geochemical (Lee, 1983;Kump and Byrne, 1989;Wood et al, 1989) and catalytic (Dressick et al, 1994;Troitskii et al, 1996) settings. The fate and transport of palladium in the environment as well as the formation of palladium deposits under hydrothermal conditions are in particular of crucial environmental and economical importance.…”