Carbon supported Ir nanoparticles modified and dealloyed with M (M = V, Co, Ni and Ti) as anode catalysts for polymer electrolyte fuel cells

Very active carbon-supported Ir modified with transition metal M catalysts (M = V, Co, Ni and Ti) were synthesized by an ethylene glycol (EG) reduction method as novel, suitable anode electrode materials for polymer electrolyte membrane fuel cells (PEMFCs) applications. IrM nanoparticles showed a narrow particle size distribution centered around 2–3 nm, and were uniformly dispersed on Vulcan XC-72 supports. Investigation of the catalytic activity by means of linear sweep voltammetry (LSV) employing a rotating disk electrode (RDE) setup has revealed that the activities of these catalysts follows the order of IrCo/C > IrV/C > IrNi/C > IrTi/C > commercial Pt/C > Ir/C toward the hydrogen oxidation reaction (HOR). Membrane electrode assemblies (MEA) prepared with the IrM/C anode catalysts demonstrated the beneficial impact of transition metal addition during catalyst synthesis, with IrCo/C and IrV/C providing the highest MEA power densities. EDX results indicated that these two catalysts contained negligible Co and V contents, respectively, indicating a beneficial dealloying effect resulting from HCl addition during catalyst synthesis. Herein, IrM/C materials are presented as promising replacements to conventional platinum based materials for utilization as anode electrocatalysts for PEMFC applications.

► IrM/C catalyst fabricated by a modified ethylene glycol reduction method. ► Effect of different transition metals in precursor solutions investigated. ► IrM/C nanoparticles demonstrate significant HOR activity and performance. ► Novel IrM/C catalysts synthesized would be very promising for PEMFC.