No Annealing Synthesis of Ordered Intermetallic PdCu Nanocatalysts for Boosting Formic Acid Oxidation

Abstract

Owing to their high catalytic efficiency and selectivity, the ordered intermetallic Pd-based nanocatalysts have greater promise than disordered nanocatalysts for formic acid oxidation reactions (FAOR). Traditionally, intermetallic nanoparticles are synthesized via the annealing of disordered alloy in a high temperature and reducing atmosphere. However, this method inevitably adds complexity and increases cost to practical application as well as leads to the destruction of nanostructures and the deactivation of nanocatalysts. Herein, monodisperse ordered intermetallic PdCu nanocatalysts are obtained through liquid phase reduction reaction in one pot without heat treatment. The results indicate that the ethylene glycol and KBr not only affect the solubilities of Pd and Cu precursors, but also facilitate the formation of the ordered intermetallic PdCu nanostructures with well-defined morphology. Compared to disordered PdCu, commercial Pd/C, and commercial Pd black nanocatalysts, the ordered intermetallic PdCu nanocatalysts display enhanced activity and durability for FAOR. The mass and specific activities are 665 mA mgPd–1 and 1.88 mA cm–2, which are 1.45, 2.67, and 4.16 and 1.21, 1.53, and 1.74 times disordered PdCu, commercial Pd/C, and commercial Pd black nanocatalysts, respectively. This work comes up with one novel approach for the preparation of ordered intermetallic PdCu nanocrystals without heat treatment.