High efficiency Pt-CeO2/carbon nanotubes hybrid composite as an anode electrocatalyst for direct methanol fuel cells

Pt-CeO2/carbon nanotubes (Pt-CeO2/CNTs), based on glucose polymerization in the inner pores of anodic aluminum oxide templates under hydrothermal conditions followed by carbonization at high temperature, were synthesized using as precursors H2PtCl6 reduced by NaBH4 and CeCl3 deposited by NaOH. Pt nanoparticles and CeO2 units were inserted onto the outer surfaces and inner surfaces of the as-prepared carbon nanotubes (CNTs). The resulting structures were characterized by scanning electron microscopy (SEM). The electrocatalytic performances of the Pt-CeO2/CNTs modified glass carbon electrodes were investigated for methanol oxidation by cyclic voltammetric and chronoamperometric measurements. It was found that compared with Pt/CNTs, the hybrid Pt-CeO2/CNTs electrodes showed superior catalytic performance when the molar ratio of Pt to CeO2 in the catalyst was about 2:1. The increased catalytic efficiency of Pt is likely to result from its combination with CeO2.