Enhanced catalytic activity of CuPd alloy nanoparticles towards reduction of nitroaromatics and hexavalent chromium.

The present work reports a surfactant-free, economically feasible chemical route to synthesize bimetallic CuPd alloy nanoparticles under hydrothermal condition. The structural and morphological characterizations of the nanoparticles are carried out by XRD, SEM/EDX, TEM, XPS and BET surface area analyses. The synthetic strategy comprises of 9:1 molar composition of Cu2+ and Pd2+ salt in the aqueous solution. The size of the nanoparticles isca. 3-4nmwith very notable specific surface area of 298m2g-1. The synthesized nanoparticles exhibit excellent catalytic performance towards the aqueous phase reduction of 4-nitrophenol and 4-nitroaniline in the presence of NaBH4 as a reducing agent. Furthermore the CuPd alloy nanoparticles also demonstrate remarkable activity towards reductive conversion of toxic Cr(VI) to less toxic Cr(III) at room temperature. Bimetallic CuPd alloy nanoparticles are catalytically more active and exhibit good recyclability in comparison to the monometallic Cu and Pd due to synergistic effect.