Electrocatalytic activity of binary and ternary composite films of Pd, MWCNT, and Ni for ethanol electro-oxidation in alkaline solutions

Binary and ternary composite films of Pd, multiwalled carbon nanotubes (MWCNTs) and Ni are obtained on glassy carbon electrodes and investigated as electrocatalysts for the ethanol oxidation reaction in alkaline medium. The steady-state anodic Tafel polarization study shows that small introduction (1–5%) of MWCNTs to Pd increases the apparent electrocatalytic activity greatly, the magnitude of enhancement, however, being the greatest (∼26 times) with 1%MWCNT. Addition of 1%Ni to the active Pd–1%MWCNT composite improved the apparent electrocatalytic activity (over 50%) further, but its higher additions (2–5%) showed an adverse effect on the apparent catalytic activity. Among the electrodes investigated, the Pd–1%MWCNT–1%Ni composite electrode has the greatest apparent electrocatalytic activity.