Boosted electrochemical oxidation of methanol at FeOx/Pd/Au ternary nanocatalyst

In this paper, a highly effective catalyst for methanol electrochemical oxidation (MEO) was developed by the sequential deposition of spherical gold nanoparticles (nano-Au) on a glassy carbon (GC) rod’s surface followed by palladium nanoparticles (nano-Pd), then, iron oxide nanoparticles (nano-FeOx) to form FeOx/Pd/Au/GC catalyst. The sequence of catalyst’s layers proved crucial in optimizing its performance towards MEO. Notably, FeOx/Pd/Au/GC electrode produced a remarkable enhancements in the catalytic activity (by 7 times) and stability (approximately 16 fold) when compared to those produced at Pd/GC rod. Additionally, the onset potential for MEO was significantly reduced by approximately 40 mV. Through material and electrochemical analyses, the catalyst's composition was validated, and the significance of each individual component was revealed. Interestingly, in FeOx/Pd/Au/GC catalyst, nano-Pd was the fundamental electro-catalyst for MEO. The underlying nano-Au played a key role in distributing nano-Pd catalyst to inhibit CO molecules adsorption on its surface, while nano-FeOx significantly enhanced charge transfer kinetics to facilitate a faster reaction mechanism for MEO.