Abstract

The goal of the present study was the investigation of bimetallic colloidal systems to be used as precursors of bifunctional catalysts dispersed on a support and as a precursor of bimetallic films. Bimetallic colloids of Ni–Cu were prepared by vaporization of an alloy and cocondensation with organic solvents at 77 K. Active powder for catalytic purposes were obtained by solvent evaporation. The chemical liquid deposition (CLD) method was used to prepare films. The colloids was characterized by several studies, including the stability at room temperature without additives, particle size growth, UV-visible (UV-vis) and Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) with energy dispersive X-ray (EDAX), and thermogravimetric analysis (TGA). The solvents under study were 2-methoxyethanol, 2-propanol, and acetone. These studies confirmed that Ni–Cu bimetallic colloids with 2-methoxyethanol were stable for months, while acetone and 2-propanol did not produce stable colloids. The studies of the (Ni-Cu)-2-methoxyethanol colloids by UV-vis demonstrated that colloids with bimetallic particles were formed. The particle size growth was slow, and particle size remained constant at 66 Å for a week. The FT-IR studies of the film prepared by evaporation of 2-methoxyethanol showed the incorporation of the solvent, which enables colloid stabilization by bonding either to Ni or Cu through the oxygens. The EDAX studies showed the presence of metallic Ni and Cu in the films. The thermal studies of the films showed a weight loss of 31.6% between 120 and 550°C.