An easy and cheap chemical route using a MOF precursor to prepare Pd-Cu electrocatalyst for efficient energy conversion cathodes

Carbon supported bimetallic palladium-copper nanoparticles (PdCu/C) were prepared using a copper metal-organic framework (MOF) as sacrificial precursor. The effect of MOF was investigated by comparing the PdCu/C synthesized from a simple metal chloride precursor (CuCl₂). The PdCu/C nanoparticles are nanorod-like particles in both cases. Based on the analysis from Warren planar defect and size-strain isotropic models, in the MOF-derived PdCu/C sample, the crystallite size, stacking-fault and micro-strain parameters increase, whereas lattice parameter decreases, with reference to both the CuCl₂-derived PdCu/C and Pd/C nanoparticles. This assesses a solid solution in the MOF-derived PdCu/C sample, while the alloying is less evident in the CuCl₂-derived sample, as supported by inductively coupled plasma and X-ray photoelectron spectroscopy data. A better oxygen reduction reaction activity obtained on MOF-derived PdCu/C, as compared to other homemade and commercial samples, is correlated to Pd surface modification induced by alloying, further proved by CO-stripping voltammograms.