关键词: 甲酸; Pd-Pb纳米粒子; 催化剂; 电催化氧化

Abstract:

Pd catalysts for formic acid oxidation had been extensively investigated due to potential application in direct formic acid fuel cells. To improve the stability of catalysts and promote the oxidation of formic acid through the direct pathway, various Pd-based bimetallic catalysts had been received much attention. In this work, Pd-Pb/C catalysts with different Pd/Pb atomic ratios were prepared by the impregnation-reduction method. The results of powder X-ray diffraction(XRD) and transmission electron microscope(TEM) measurement indicated that both crystal lattice constant and particle size of Pd-Pb alloy nanoparticles increased and decreased with increasing Pb/Pd atomic ratio, respectively. The electrocatalytic oxidation of formic acid at Pd-Pb/C catalysts with different Pd/Pb atomic ratios was studied by cyclic voltammetry, CO-stripping and chronoamperometry measurements. It was found that the electrocatalytic activation of Pd-Pb/C electrocatalysts for formic acid oxidation decreases with the increase of Pb/Pd atomic ratio. This may be attributed to the addition of Pb, which results in the poison of Pd catalyst.

Key words: Formic acid; Pd-Pb nanoparticle; Catalyst; Electrocatalytic oxidation