Rational design of FeS microspheres as high-performance catalyst for electrooxidation of hydrazine

Inspired by the relatively recognized performance of transition metal sulfides in the oxidation of hydrazine, the catalytic properties of FeS and FeS are compared via the density functional theory calculations. Due to the different coordination numbers of iron-sulfur, the free energies of the dehydrogenation steps on FeS are far less than those on FeS, which led to the much better catalytic performance of FeS. Accordingly, FeS microspheres are rationally proposed as a more efficient electrocatalyst for hydrazine oxidation, which is then prepared by a facile one-step hydrothermal strategy. Such FeS microspheres show great activity for hydrazine oxidation with an onset oxidation potential of 0.22 V vs. reversible hydrogen electrode, and a peak current density of 16 mA cm. Meanwhile, stability and high faradaic efficiency (3.5e/NH) is obtained for hydrazine oxidation to N.