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The principal possibility of processing the industrial poor collective concentrates of platinum group metals (pgms) using a hydrocarbonyl technology with the selective concentration of pgms from poor multicomponent chloride and chloride-sulfate solutions with the subsequent production of pure pgms is shown.

This minireview presents the results that show the potential of molecular nitrogen fixation by carbonyl cluster compounds of platinum metals at room temperature and atmospheric pressure to produce ammonia or its derivatives. Although the main attention is given to processes with the participation of derivatives of platinum and palladium, it was demonstrated that molecular nitrogen fixation is characteristic of all the platinum metals, except osmium.

X-ray diffraction, IR spectroscopy, and thermogravimetry and analyses of the composition of platinum carbonyl destruction products showed that oligomeric platinum carbonyl [Pt(CO)2]n is unstable in the air at room temperature and quickly decomposes with the loss of CO ligands due to their removal from the complex as a result of CO dissociation and CO ligand oxidation by atmospheric oxygen. The destruction processes of platinum carbonyl [Pt(CO)2]n and the composition of destruction products were described.

Carbonyl palladium blacks are formed on treatment of Pd(II) chloride complex in a solution with carbon monoxide at ambient pressure and a temperature ≥20°C. The results of IR spectroscopy, powder X-ray diffraction, and electron microscopy demonstrated that carbonyl palladium blacks are heterogeneous unstable systems consisting of palladium, carbon, and oxygen, the ratio of which changes upon heat treatment. Palladium is present as the metal, the carbonyl cluster Pdx(CO)y, and the variable-composition PdCx phase, while carbon partly occurs as amorphous diamond with sp3 hybridization of atoms. After calcination of Pd black at 1000°C, a large amount of carbon remains in the resulting Pd sponge, which acquires abrasive properties. Dissolution of the sponge in aqua regia leaves a solid phase with a high carbon content

A novel process for the recovery of platinum group metals (pgms) from ternary alloys using a hydrocarbonyl process is proposed. The hydrocarbonyl process involves treatment of a chloride solution of the pgms with carbon monoxide at ambient pressure. The results demonstrate that the process can provide high purity pgms from a ternary platinum-rhodium-palladium alloy such as that obtained from palladium-nickel catchment alloys used with platinum-rhodium gauzes during high temperature ammonia oxidation.