Employing iron and nickel to enhance ethanol oxidation of Pd-based anodes in alkaline medium

• Published in: Electrochimica acta 2019-02, Vol.295 (C), p.751-758
• Main Authors: Almeida, T.S., Yu, Y., de Andrade, A.R., Abruña, H.D.
• Format: Article
• Language: English
• Subjects: Anodes; Anodizing; Catalysis; Catalysts; Composition; Crystallites; Electrocatalysis; Electrocatalysts; Ethanol; Ethanol oxidation; Fuel cells; Iron; Iron and nickel; Nanoparticles; Nickel; Oxidation; Palladium; Pd-based catalyst
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2018.10.187

We report the addition of Fe or Ni to Pd:M electrocatalysts supported on Vulcan carbon XC-72 with 20 wt% metal loading to activate ethanol electrooxidation reaction in alkaline medium. Experimental bulk compositions of nanoparticles were very close to the nominal one. All the catalysts display the fcc crystalline structure of palladium with crystallite sizes ranging from 2.5 nm to 5.4 nm. Electrochemical tests in the presence of ethanol shows that the addition of Fe and Ni to Pd catalysts enhances ethanol electrooxidation. Ni-containing compositions such as Pd(56)Ni(44) and Pd(71)Ni(29) exhibit excellent catalytic mass activity (30 A gPd−1) at 0.5 V vs. RHE showing that they are promising anode electrocatalysts for direct ethanol alkaline fuel cells. [Display omitted] •Pd-M/C (M = Ni or Fe) catalysts were prepared by the microwave method.•This method is advantageous because easy, fast and promotes small nanoparticles.•Pd(50)M(50) compositions yielded the highest catalytic activity.•Ni addition affected the activity towards ethanol electrooxidation more markedly than Fe.•We obtained catalytic activity 30 mA gPd−1 for Pd(50)Ni(50) confirming the beneficial effect of adding Ni.