Novel methanol-tolerant Ir-S/C chalcogenide electrocatalysts for oxygen reduction in DMFC fuel cell

Novel methanol-tolerant oxygen-reduction catalysts, iridium-sulphur (Ir-S) chalcogenides with differ ent Ir/S atomic ratios, were synthesized via a precipitation method using H21rCI6 and Na2SO3 as the Ir and S precursors. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the IrxSl-x/C chalcogenide catalysts. Particle size ranging from 2.5 to 2.8 nm though obvious agglomeration was found on carbon support. However, these chalcogenide catalysts showed strong catalytic activity towards the oxygen reduction reaction (ORR) and high methanol tolerance, strongly suggesting these novel catalysts as promising candidates for direct methanol fuel cell (DMFC) cathode applications.