Novel honeycomb nanosphere Au@Pt bimetallic nanostructure as a high performance electrocatalyst for methanol and formic acid oxidation

Graphical abstract: - Highlights: • Novel Au@Pt honeycomb nanospheres were firstly prepared. • This catalyst was formed by the self-assembly of ultrafine Au@Pt nanoparticles. • Vital role of CTAB in the formation of honeycomb nanosphere was discussed. • Enhanced electrocatalytic performance of Au@Pt honeycomb was obtained. • Formic acid electrooxidation on the catalyst follows a dual path mechanism - Abstract: A novel honeycomb nanosphere bimetallic catalyst with a diameter of 27.5 ± 1.8 nm was formed by the self-assembly of the ultrafine irregular cubic Au@Pt nanoparticles (4.6 ± 0.5 nm). The vital role of CTAB in the formation of the honeycomb nanosphere was discussed. The specific (mass) activity of this catalyst is ca. 2.5 (1.6) times that of Pt black for methanol electrooxidation and 3.2 (2.3) times that of Pt black for formic acid electrooxidation. The excellent electrochemistry performance may be attributed to the electronic interaction between Au and Pt and the unique structure of the honeycomb nanosphere