Comparative study of catalyst effect on ethanol electrooxidation in alkaline medium: Pt- and Pd-based catalysts containing Sn and Ru

The ethanol oxidation reaction (EOR) on Pd:Mand Pt:M-based nanocatalysts (M = Sn or Ru) was investigated by using electrochemical and chromatographic methods. These carbon-supported materials were prepared by the microwave-assisted method. The experimental bulk compositions of the Pt-based catalysts were very close to the nominal composition, and all the catalysts displayed the Pt or Pd fcc crystalline structure with crystallite sizes ranging from 1.6 to 6.8 nm. The Pd-based catalysts presented much higher catalytic activity and stability than the Pt-based ones. Electrolysis (HPLC) showed that the Pd:M catalysts are good materials for C2 (acetaldehyde and acetic acid) byproduct production and improve the yields of ethanol consumption as compared to the poor activity of the Pt:M catalyst in basic medium. In alkaline medium, the co-catalyst did not lead to the huge differences observed in acidic medium. Pd:Ru/C proved to be the best catalyst for EOR in basic medium, surpassing the activity of Sn, which is known as the most active catalyst for this reaction in acidic medium. (c) 2020 Elsevier B.V. All rights reserved.