Study of sorption of platinum and palladium cyanometallate complexes as the key to understanding the mechanism of binding the [Au(CN)2]− anion with carbon adsorbents

Abstract

Goldcarb WSC-207C GR activated carbons with platinum and palladium complexes adsorbed from aqueous solutions of K2[Pt(CN)4], K2[Pt(CN)6], and K2[Pd(CN)4] were studied by the methods of X-ray photoelectron spectroscopy and IR spectroscopy with Fourier transformation, and also by MALDI massspectrometry. Platinum and palladium cyanide complexes are not reduced onto surface of active charcoal while adsorption. A certain part of the [Pd(CN)4]2− and [Pt(CN)4]2− anions directly bound to active centers on the activated carbon is oxidized more deeply and functions as particles-anchors, forming oligomers resembling Krogmann salt. A correspondence between the structure of the complex cyanometallate ion and a mode of its binding with active carbon is found. The adsorption of complex species with a linear structure or a square planar structure is defined by a possibility of the formation of donor-acceptor and metallophilic bonds. The mode of the anion [Au(CN)2]− binding with the surface of active carbon was considered.