An improved acrylamide sol-gel technique using a microwave oven in order to synthesize bimetallic Rh-Pd particles is reported and discussed. The synthesis of Pd and Rh nanoparticles was carried out separately. The polymerization to form the gel of both Rh and Pd was carried out at 80°C under constant agitations. The method chosen to prepare the Rh and Pd xerogels involved the decomposition of both gels. The process begins by steadily increasing the temperature of the gel inside a microwave oven (from 80°C to 170°C). In order to eliminate the by-products generated during the sol-gel reaction, a heat treatment at a temperature of 1000°C for 2？h in inert atmosphere was carried out. After the heat treatment, the particle size increased from 50？nm to 200？nm, producing the bimetallic Rh-Pd clusters. It can be concluded that the reported microwave-assisted, sol-gel method was able to obtain nano-bimetallic Rh-Pd particles with an average size of 75？nm. 1. Introduction Bimetallic alloy (solid solutions or intermetallics compounds) nanostructures, synthesized from two single components, have been of interest because of their superior properties, in comparison with their respective single-component species, that is, Ag, Pd, Rh, and so forth [1]. The synthesis of noble metals and alloys, in nanometric scale, has been extensively investigated in nanotechnology because of their optical and electronic properties, as well as for their useful applications in many fields such as medicine [2], catalysis, and sensors [3–6]. Hardness, high melting and boiling points, and high thermal and electrical conductivity are some of the existing properties of these noble metals. Rhodium and palladium (Rh and Pd) crystallize in a face centered cubic (fcc) unit cell. Both metals add s electrons to the collective d band of palladium [7] and increase the lattice parameter of the palladium host lattice [8, 9]. It was found that rhodium behaves as an absorber of hydrogen at high pressure of gaseous hydrogen when situated within the palladium lattice [10, 11]. Recently, Pd nanocrystals have been prepared in aqueous solutions giving rise to a great variety of shapes, including truncated octahedron, cube, octahedron, and thin plate [12–14], making them ideal candidates as seeds for growing bimetallic nanostructures. The control of crystal size and its dispersion are among the main goals of nanocrystal preparation. This is due to the physicochemical properties of a bimetallic nanocrystal that can be tailored by controlling their particle size, shape, and elemental composition, as well as
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