Triethanolamine as an efficient electrolyte additive for borohydride electrooxidation on Ni based catalyst

Abstract

As a non-noble metal, nickel (Ni) is considered as an ideal alternative of noble metal catalysts for borohydride electrooxidation in the direct borohydride fuel cell (DBFC). In this work, triethanolamine (TEA) was employed as additive in electrolyte to improve the performance of Ni based catalyst for borohydride electrooxidation. The cyclic voltammetry measurement showed that the peak current density of oxidation peak for borohydride electrooxidation after 10 cycles remained 59% of that of the first cycle when 0.108 mol·L-1 TEA was added. As a contrast, the oxidation peak of the tenth cycle decreased by 99.3% when TEA was absent. The electrochemical impedance spectra (EIS) showed that TEA could significantly decrease the charge transfer resistance for borohydride electrooxidation on the Ni electrode. Chronoamperometry (CA) result indicated the anodic current could be also enhanced by adding TEA. More importantly, we believe TEA can also be employed in various kinds of Ni based catalysts for borohydride electrooxidation.