New Complex Salts as Precursors of Porous Pd-Ir-Rh Nanoalloys

New complex salts [Pd(NH3)(4)](3)[Ir(NO2)(6)](2x)[Rh(NO2)(6)](2-2x) (II-VI) were prepared, which are solid solutions based on double complex salts [Pd(NH3)(4)](3)[Ir(NO2)(6)](2) (I) and [Pd(NH3)(4)](3)[Ir(NO2)(6)](2). The obtained compounds were characterized by X-ray powder diffraction analysis, IR spectroscopy, and elemental analysis. The compounds crystallize in the cubic system (space group F4 (3) over barc). The thermal behavior of compounds I-VI in various gas atmospheres was investigated. The final products of thermolysis of [Pd(NH3)(4)](3)[Ir(NO2)(6)](2x)[Rh(NO2)(6)](2-2x) in reducing (H-2) and inert (He) atmospheres were trimetallic porous Pd-Ir-Rh nanoalloys. The final products of thermolysis in an oxidizing atmosphere were mixtures of metal oxide phases with an admixture of a metal phase. The structural and morphological properties of the formed nanoalloys were studied. The obtained solid solutions of double complex salts [Pd(NH3)(4)](3)[Ir(NO2)(6)](2x)[Rh(NO2)(6)](2-2x) were used to synthesize alloy nanoparticles on the surface of a gamma-Al2O3 oxide support. The catalytic activity and stability of the produced catalyst samples were tested in a model reaction of CO oxidation under forced thermal aging conditions.

Automated summary

A new complex salt was synthesized and characterized through various analytical methods. The compound exhibited specific crystal structure and thermal behavior, leading to the formation of trimetallic nanoalloys and metal oxide phases. The obtained alloy nanoparticles were used as catalysts and tested for their catalytic activity and stability in a CO oxidation model reaction.