Production of an ordered (B2) CuPd nanoalloy by low-temperature annealing under hydrogen atmosphere

Abstract

CuPd (1/1) nanoalloys composed of disordered body-centered-cubic crystals (crystal size = 1.6 nm) were prepared by synchronous reduction of Cu and Pd precursor ions with NaBH₄. In situXRD measurement revealed that Cu and Pd atoms in the CuPd nanoalloys are arranged into an ordered B2 structure under exposure to H₂ (5 kPa) at 373 K. Ordering of Cu and Pd atoms over a longer distance (up to 3.6 nm) was achieved by annealing the nanoalloys for a longer time under a H₂ atmosphere.