Shao Zhigang

Bifunctional electrodes with a thin catalyst layer for 'unitized' proton exchange membrane regenerative fuel cell

Abstract A bifunctional electrode structure for a unitized proton exchange membrane regenerative fuel cell has been developed. The electrode has only a thin catalyst layer; it reduces the loading of the catalyst to 0.4 mg cm−2, and minimizes mass transport and ohmic limitations. A satisfactory performance of a unitized proton exchange membrane fuel cell is achieved with this electrode structure. 50 wt.% Pt+50 wt.% IrO2 is a good bifunctional catalyst for the oxygen electrode. Examination of this catalyst by transmission electron microscopy and of the electrode by scanning electron microscopy is reported.

Preparation of monodispersed ultra-small PtCu alloy with remarkable electrocatalytic performance

Without the assistance of sufactant, CuCl2 was reduced by NaBH4 to form Cu nanoparticles, which acted as second dispersant during the preparation of PtCu alloy. The obtained PtCu of 2.1 nm was supported on Vulcan XC72. The PtCu/C showed lattice compression, Pt surface segregation, and high ratio of non-oxidized Pt with high electronic binding energy. All those structure feature contributed to weak adsorption strength of OHads on Pt, which had benefit on ORR. According to half cell test, the area specific activity and mass activity of PtCu/C reached 6.6 and 3.8 times that of Pt/C at 0.9 V vs. RHE. What’s more, after degradation test of 10000 cycles, the superiority of PtCu/C towards Pt/C remained. At 100 mA/cm2 in single cell test, ultra-small PtCu/C displayed superior performance and stability. Besides, this method in this article can also be used to synthesize supported ultra-small alloy, such as PtCo and PtNi.