Trimetallic PtNiCo Alloy-Anchored Nanoporous Gold Composites as Effective Ethanol Oxidation and Oxygen Reduction Bifunctional Electrocatalysts

Alloying Pt with other 3d transition metals to form bimetallic or trimetallic Pt-based catalysts can effectively solve the poor durability of the current fuel cell Pt catalysts. Here, we prepared a trimetallic PtNiCo alloy-anchored nanoporous gold (NPG) film composite (referred to as NPG-PtNiCo) bifunctional catalyst toward ethanol oxidation reaction (EOR) and oxygen reduction reaction (ORR), in which the average ligament size of the NPG film is about 37.2 nm. The prepared NPG-PtNiCo catalyst exhibited higher specific and mass activities for EOR (7.02 mA·cm –2 and 2.02 A·mg Pt –1 ) and ORR (2.14 mA·cm –2 and 0.68 A·mg Pt –1 ) than NPG-Pt, NPG-PtNi, and NPG-PtCo catalysts in an acidic electrolyte. Moreover, after chronoamperometry and cyclic voltammetry cycle tests, NPG-PtNiCo possessed better stability than other catalysts. The superior catalytic properties originate fundamentally from a synergistic effect among Pt, Ni, and Co. In addition, the robust NPG film is conducive for the enhancement of catalytic performance. This work can give an insight for preparing trimetallic Pt-M (M = nonprecious metals)-anchored NPG composite bifunctional fuel cell catalysts.