Two-Step Fabrication of Carbon-Supported Cu@Pd Nanoparticles for Electro-Oxidation of Formic Acid

Core-shell structure Cu@Pd/C catalysts were prepared in two steps combining microwave-assisted glycol reduction and chemical impregnation method for the first time. Compared with the traditional one-step synthesis of PdCu/C alloy catalysts by microwave (marked as M-PdCu/C) and impregnation (denoted by I-PdCu/C) method, respectively. The Cu@Pd/C catalysts were prepared in two-step show better catalytic performance toward formic acid oxidation, due to its special core-shell structure and better dispersion. On this basis, different proportions of Cu-x@Pd-y/C (x:y = 1:1, 1:2, 1:3, 1:4 and 1:5) catalysts were synthesized by the two-step strategy. The relationship between lattice strain, electron distribution and catalytic performance were explored by physical and chemical characterization. X-ray diffraction and X-ray photoelectron spectra analyses showed that the introduction of Cu lead to the lattice contraction and modified electronic structure of Pd. The electrochemical test showed that Cu@Pd-3/C sample has the highest activity toward formic acid electro-oxidation. Its mass activity is about 3.3 times that of Pd/C catalyst that was synthesized by impregnation method (labelled as I-Pd/C). At the same time, the Cu@ Pd-3/C catalyst also demonstrated improved stability. [GRAPHICS] .