Fabrication of BixPdy bimetallic materials characterized by catalytic activity at low temperature: Nitro reduction and Suzuki - Miyaura coupling reactions under green conditions

Abstract

A simple method for synthesizing the BixPdy bimetallic particles is described. The structure, composition distribution and size of synthesized BixPdy bimetallic particles were characterized using a number of analytical techniques. The Bi:Pd atomic ratio (x:y) of the nanoparticles was determined to be approximately 1:3 (Bi24Pd76), 1:1 (Bi54Pd46) and 3:1 (Bi74Pd26). The (111) diffraction peaks within the X-ray diffraction patterns of the bimetallic nanoparticles shifted from 39.9 degrees to 38.5 degrees as the Bi content increased from 0% to 75%. The d-spacings calculated from the 20 data of (111) planes were 2.33, 2.34, 2.32 and 2.26 nm for nanoparticles with a Bi:Pd atomic ratio of 3:1, 1:1, 1:3 and 0:1 respectively. The crystalline properties of the surface of the BixPdy bimetallic nanoparticles were observed in high-resolution transmission electron microscopy analysis. The d-spacings between the adjacent lattice planes were measured on the surface of BixPdy bimetallic nanoparticles by averaging 10 lattice fringes distance. A regular face-centered cubic lattice was observed throughout the prepared BixPdy bimetallic nanoparticles. The lattice d-spacing of the Bi3Pd1, Bi1Pd1 and Bi1Pd3, bimetallic nanoparticles was approximately 2.34, 2.33 and 2.32 angstrom, respectively, which can be indexed to the (111) planes. These measurements correspond to the values calculated using the Bragg equation (d = n lambda/2sin theta). The catalytic activity of BixPdy bimetallic nanoparticles was determined for the nitro compound reduction and Suzuki-Miyaura coupling reactions under green conditions (in an aqueous solution). Bi1Pd3 nanoparticles were shown to provide the best catalytic performance during both reactions, resulting in a yield of 98% in both cases.