Enhanced stability and efficiency of Pd electrocatalysts towards electrooxidation of ethanol using CNT-CNF supporting materials

Pd electrocatalysts supported on carbon nanotubes (CNTs) and carbon nanofibres (CNFs) and their combination thereof were evaluated for their effective ethanol oxidation reaction. The electrocatalysts (namely Pd/CNT, Pd/ CNF and Pd/CNT-CNF) were synthesized and characterized using BET, TEM, XRD, TGA and Raman spectroscopy techniques. Electrochemical characterization using cyclic voltammetry in the presence of [Fe(CN)₆]^3/-4 redox probe showed that the electrocatalysts exhibited excellent current response on glassy carbon electrode in the order of Pd/CNT > Pd/CNF > Pd/CNT-CNF. In contrast, in alkaline ethanolic solution, the order of oxidative current response was Pd/CNF < Pd/CNT < Pd/CNT-CNF, implying better electrocatalytic activity for the ternary electrocatalysts. The superiority of Pd/CNT-CNF over other electrocatalysts was further revealed using chronoamperometry (current density: 51.52, 13.31 and 11.25 mA cm^-2 for Pd/CNT-CNT, Pd/CNF and Pd/CNT, respectively). Furthermore, the ternary electrocatalysts demonstrated excellent stability after 1500 cycles, making it attractive as a durable electrode for fuel cell technology development. (author)