PdAu Alloy Nanoparticles for Ethanol Oxidation in Alkaline Conditions: Enhanced Activity and C1 Pathway Selectivity

Ethanol is a promising fuel for renewable energy applications due to its high energy density and sustainability. However, complete electrooxidation of ethanol in both acid and alkaline conditions is still challenging, and the effect on the oxidation selectivity is not well-studied. Here, we investigate the effect of PdAu alloy nanoparticle (NP) compositions on the activity and selectivity of the ethanol oxidation reaction (EOR) in alkaline solution. The Au-rich Pd34Au66 NPs show a peak mass activity of ∼19.5 A/mgPd and specific activity of ∼16.5 mA/cm2. Through product analysis after bulk electrolysis, we conclude that C–C cleavage is enhanced on the PdAu alloy NP surface and the C1 pathway (complete EOR to CO2) selectivity on Pd34Au66 reaches ∼58% at 0.6 V. A “volcano” trend is observed on both EOR activity and C1 pathway selectivity on PdAu NPs, which is correlated to the electronic and structural modification due to the alloy formation.