The yolk-shell Fe3O4-polyaniline for decoration of Pd-Ni nanoparticles (yolk-shell Fe3O4-PANI/Pd-Ni) were synthesized and used as a new electrocatalyst for oxidation of formic acid. The yolk-shell Fe3O4-PANI/Pd-Ni catalyst provided superior catalyst performance for formic acid oxidation in H2SO4 aqueous solution. These yolk-shell Fe3O4-PANI/Pd-Ni catalysts were found to be more resistant to deactivation in the oxidation of formic acid than yolk-shell Fe3O4-PANI/Pd and Pd/C and to consistently show better long-term performances. The enhanced catalytic performance may arise from the unique structure and surface properties of the yolk-shell Fe3O4-PANI and bi-functional effect, which process extraordinary promotional effect on Pd catalyst.
