Surfactant-free monodispersed Pd nanoparticles template for core-shell Pd@PdPt nanoparticles as electrocatalyst towards Methanol Oxidation Reaction (MOR)

Abstract

An eco-friendly two-step synthetic method for synthesizing Pd@PdPt/CNTs nanoparticles was introduced and studied for the methanol oxidation reaction. The Pd@PdPt alloy core-shell structure was synthesized by preparing a surfactant-free monodispersed Pd/CNTs precursor through the hydrolysis of tetrachloropalladate (II) ion ([PdCl₄ ] ²⁻ ) in the presence of carbon nanotubes (CNTs) and the subsequent hydrogen reduction and followed by a galvanic replacement reaction. This method opens up an eco-friendly, practical, and straightforward route for synthesizing monometallic or bimetallic nanoparticles with a clean surfactant-free electrocatalytic surface. It is quite promising for large-scale preparation. The Pd@PdPt/CNTs electrocatalyst demonstrated a high specific mass activity for methanol oxidation (400.2 mAmgᴘₜ⁻¹) and excellent stability towards direct methanol oxidation compared to its monometallic counterparts.