New non-platinum Ir–V–Mo electro-catalyst, catalytic activity and CO tolerance in hydrogen oxidation reaction

Very active 40%Ir–10%V–3%Mo/C and 40%Ir–10%V–10%Mo/C (in weight) catalysts, as novel, suitable anode electrode materials in polymer electrolyte membrane fuel cells (PEMFCs), have been synthesized by an ethylene glycol (EG) reduction method. The nanostructured catalysts have been characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM). Ir nanoparticles, after modification with V and further with Mo, show a narrow particle size distribution centered at 2 nm, and are 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) has revealed that 40%Ir–10%V–10%Mo/C catalyst exhibited very high electrocatalytic activity toward the hydrogen oxidation reaction (HOR). About 77% higher current density was obtained for 40%Ir–10%V–10%Mo/C compared to that of 40 wt.% commercial carbon-supported platinum catalyst (Pt/C), and 282% higher current density compared to that of the pure 40 wt.% Ir/C at 0.1 V versus RHE. The performance of a membrane electrode assembly (MEA) prepared with the 40%Ir–10%V–10%Mo/C as the anode catalyst generated a maximum power density of 598.4 mW cm−2 at 70 °C, which is 26.4% higher than that of commercially available Pt/C under air/H2 testing condition. The ternary 40%Ir–10%V–10%Mo/C catalyst was also tested for 10 ppm CO tolerance, and the results showed that the 40%Ir–10%V–10%Mo/C has much better CO tolerance than commercial Pt/C catalyst. The mechanism of the ternary 40%Ir–10%V–10%Mo/C catalyst may be a bi-functional mechanism.

► Ir–V–Mo/C catalyst fabricated by a modified ethylene glycol reduction method.
► Effect of different Mo contents in precursor solutions investigated.
► Ir–V–Mo/C nanoparticles demonstrate significant HOR activity and CO tolerance.
► Novel Ir–V–Mo/C catalysts synthesized would be very promising for PEMFC.