AgPdCo hollow nanospheres electrocatalyst with high activity and stability toward the formate electrooxidation

The widespread commercial application of direct formate fuel cell (DFFC) is limited by the lack of efficient electrocatalysts for the formate oxidation reaction (FOR). AgPdCo hollow nanospheres (H-NSs) with jagged surfaces are successfully synthesized via a facile method involving the wet-chemical synthesis of AgPdCo nanospheres (NSs) and galvanic replacement reaction between Pd salt and AgPdCo NSs. Surpassing Ag₃₀Pd₆₉Co₁ NSs and most of previously reported electrocatalysts, Ag₉Pd₉₀Co₁ H-NSs exhibit extremely high FOR activity with a peak current density of 3.08 A·mg_Pd^-1. Apart from the competitive activity, Ag₉Pd₉₀Co₁ H-NSs show greatly improved chronoamperometric and cycling stability, whereby the current density retains about 0.24 A·mg_Pd^-1 after 3,600 s electrocatalysis and the mass activity maintains 54.06% of the initial value after 500 cycles. The unique hollow nanosphere and synergistic effect are responsible for the enhanced activity and stability. This study will provide new clues for the development of outstanding electrocatalysts.