The high activity associated with platinum electrocatalyst for ethanol oxidation is tempered with its easy deactivation by CO species and its expensive nature as a noble metal. This work investigates the synthesis of highly active non-noble metal elctrocatalyst based on Cobalt (Co), Nickel (Ni), and Molybdenum (Mo) for ethanol oxidation. As-deposited Co-Ni-Mo electrocatalyst on carbon support was evaluated for ethanol oxidation. The electrocatalyst was prepared by electroless deposition method on carbon substrate support (CCS) made active for electroless deposition with Pd-ink. The effects of electroless deposition time, and reaction temperature (30-60°C) were studied. The result showed that CoNiMo/CCS was highly active in alkaline ethanol solution (0.5M NaOH+1 M EtOH) for ethanol oxidation. The temperature effect on the performance of the catalysts prepared at different times will be discussed. Although minor amount of Pd (< 50 μg/cm²) was used to make the carbon substrate active for electroless deposition, the results obtained showed that the Pd, was not utilized in ethanol oxidation. Therefore, the catalytic activity observed for the reaction is attributed to Co, Ni, and Mo, in the catalyst and not from Pd. Tafel analysis showed that the exchange current density for the catalyst prepared at 30 minutes deposition time was an order of magnitude higher than that reported for Pt (0.001´10^-5A/cm², [1]), and Pt/C (0.033´10^-5A/cm², [1]). This suggests that the catalyst has a better ability at handling CO deactivating species than Pt. Furthermore, the linearity of the peak potential with the logarithm of scanning rates confirms the irreversibility of ethanol electrooxidation . Overall, this study provides a promising novel and effective non-noble electrocatalyst with an onset potential of 0.05 V (Ag/AgCl).

[1]. Xu C, Shen PK, Ji X, Zeng R, Liu Y. Enhanced activity for ethanol electrooxidation on Pt–MgO/C catalysts. Electrochem Commun. 2005;7:1305–8.

Keywords: Cobalt, Nickel, Molybdenum, Electroless, Ethanol Oxidation, Tafel.