PdCo Nanoparticles Formation at HOPG and High Surface Area Carbon Support Vulcan XC-72R

Abstract

Thermal reduction of PdCo molecular precursors may lead to the controlled production of nanoparticles on high surface area carbon supports that can be used as methanol tolerant oxygen reduction catalysts for direct methanol fuel cells (DMFC). Following this concept, a single molecular precursor source was used for the synthesis of bimetallic nanoparticles on highly oriented pyrolytic graphite (HOPG) and Vulcan (VC) carbon supports. Nanostructural formation of palladium-cobalt on highly ordered pyrolytic graphite (HOPG) was study by AFM, SEM and voltammetry. The relative humidity during precursor deposition was used to control the rings self-formation on HOPG surfaces. Palladium and palladium-cobalt nanoparticles were also formed on high surface area carbon support (Vulcan XC-72R) by thermal reduction and characterized by TEM. The Pd/VC and PdCo/VC nanoparticles were tested for the oxygen reduction reaction (ORR) with and without methanol. The Pd-based catalysts have ORR activity and high methanol tolerance.

Surface analysis and electrochemical characterization of palladium–cobalt nanoring formation from molecular precursor, [Et3NH]2[CoPd2(μ‐4‐I‐3,5‐Me2pz)4Cl4], on highly ordered pyrolytic graphite

“…In the magnified image of the Pd 2 Co ring, it can be observed that the reduction promotes the formation of nanoparticles (Fig. (b)) . XPS spectrum confirmed the reduction of the Pd 2 Co precursor because the N, I and Cl photoemission peaks disappear, and Pd and Co binding energy (BE) peaks shift toward lower binding energies (Section on XPS Analysis).…”

Synthesis and Characterization of Palladium and Palladium–Cobalt Nanoparticles on Vulcan XC-72R for the Oxygen Reduction Reaction

“…The electrocatalysts performance depends of the synthesis method. The demand for tailored catalytic nanoparticles has encouraged the use of heterobimetallic molecular precursors. − The advantage of the heterobimetallic molecular precursors for the synthesis of bimetallic and alloy nanoparticles is that the metal ratio is predetermined by the stoichiometry of the precursor.…”