The enhancement effect of nitrogen, fluorine-codoped titanium dioxide on the carbon supported platinum nano-catalyst for methanol electrooxidation reaction

Abstract

TiO2 (anatase) codoped with nitrogen and fluorine is synthesized by a simple solid state route, using urea and ammonium fluoride as sources of nitrogen and fluorine, respectively. N,F–TiO2 and carbon are mixed up physically as hybrid support of Pt nanoparticles for methanol electrooxidation. TEM shows that the utilization of the hybrid support leads to the uniform distribution and small particles size of Pt nanoparticles (Pt NPs) in Pt–N,F–TiO2/C catalyst. COad stripping experiment results indicate that the addition of N,F–TiO2 facilitates the oxidative removal of CO on Pt surface. Furthermore, cyclic voltammetric and chronoamperometric experiments show that the prepared Pt–N,F–TiO2/C catalyst exhibits much better catalytic activity and stability compared to Pt–TiO2/C, Pt/C (JM) and Pt/C (hm) catalysts. For instance, the peak current and the stable current at 7200 s of the Pt–N,F–TiO2/C catalyst are about 1.85 and 2.66 times of the Pt/C (JM) catalyst. The catalytic performance of the Pt–N,F–TiO2/C is also evaluated in a direct methanol fuel cell (DMFC), which exhibits a maximum power density of 51.6 mW cm−2, 1.65 times of an analogs fuel cell using Pt/C (JM) as an anode catalyst. Therefore, the N,F–TiO2 has great application prospect as a high-performance electrocatalyst support for methanol electrooxidation in DMFC.