Electrocatalysis by design: Synergistic catalytic enhancement of formic acid electro-oxidation at core-shell Pd/Pt nanocatalysts

The modification of a glassy carbon (GC) electrode with palladium (PdNPs) and platinum (PtNPs) nanoparticles is targeted to fabricate efficient anodes for the formic acid (FA) electro-oxidation (FAO). A proper adjustment of the deposition sequence and loading of PdNPs (as a shell) over PtNPs (as a core) of the nanocatalyst could eventually enhance its electrocatalytic activity towards FAO in such a way suppressing the CO poisoning pathway. It also improved the prolonged mechanical stability of the catalyst over a prolonged time of continuous electrolysis of FA. The highest oxidation efficiency, in terms of the catalytic activity and stability, is obtained at the Pd/Pt/GC electrode (with PtNPs directly deposited onto the GC electrode followed by ca. 6 monolayers of PdNPs). The role of PdNPs and PtNPs in the catalytic enhancement is discussed.