Void-Enriched and Highly Strained Porous Au–Ag Nanoalloy as a Bifunctional Electro-Catalyst in Alkaline Direct Alcohol Fuel Cell

Abstract

A void-enriched and highly strained porous Au−Ag nanoalloy (NP alloy ) has been synthesized from Au−Ag core−shell nanostructure by employing a galvanic replacement reaction and introducing Kirkendall voids in it. Obtained NP alloy acts both as an efficient cathodic and anodic material for methanol, ethylene glycol, and glycerol oxidation as well as oxygen reduction reactions simultaneously in an alkaline medium. High catalytic efficacy (low onset potential (E on ) and high current density (j)), wide thermal stability, and positive alcohol tolerance response of NP alloy sets them as a practical bifunctional electrode coating alternative compared to Pt/C in designing an efficient alkaline direct alcohol fuel cell.

(Ag@AuAg)@Ag Nanocatalyst for the Electrocatalytic Oxygen Reduction Reaction

“…The Au seed is prepared by a known protocol, as described in the Supporting Information (SI). The first growth step, 22 i.e., the development of NP Au−Ag 1 was performed in the presence of cetyltrimethylammonium chloride (CTAC) as a surfactant by incubating at 80 °C. In the second growth step, 22 a Au layer over the NP Au−Ag 1 structure was made by adding Au 3+ as the metal precursor and cetyltrimethylammonium bromide (CTAB) as the surfactant at room temperature, where NP Au−Ag 1 acts as the seed.…”

Galvanic replacement reaction to prepare catalytic materials

“…A modification in composition was observed from Ag‐rich to Pt‐rich with repeated cycling, and after about 10 000 cycles, the nanocages exhibited the highest specific activity of 1.23 mA cm −2 . Similarly, the Au‐Ag nanoalloy prepared from the Au–Ag core–shell structure by GRR coupled with Kirkendall voids had a highly porous structure with catalytically active dangling bonds that helped boost the sluggish ORR kinetics 113 . With high specific activity (0.764 mA cm −2 ), high mass activity (2.67 mA mg −1 ), and low onset potential (−0.2 V), the Au‐Ag nanoalloy was found to be a suitable electrocatalyst for ORR.…”

“…Similarly, the Au-Ag nanoalloy prepared from the Au-Ag core-shell structure by GRR coupled with Kirkendall voids had a highly porous structure with catalytically active dangling bonds that helped boost the sluggish ORR kinetics. 113 With high specific activity (0.764 mA cm À2 ), high mass activity (2.67 mA mg À1 ), and low onset potential (À0.2 V), the Au-Ag nanoalloy was found to be a suitable electrocatalyst for ORR. The bimetallic PdCu nanowires and PdCu nanotubes produced by the interdiffusion of Pd and Cu atoms on the surface of the nanowires and nanotubes of Cu exhibited better ORR performance than the selfsynthesized PdCu NPs and commercial catalysts.…”

Synergistic Effect of Oxygen Vacancy-Rich SnO2 and AgCl in the Augmentation of Sustained Oxygen Reduction Reaction

“…Hence, research is in progress in various perspectives and directions to replace fossil fuels with suitable alternatives. Fuel cells are one of the most promising energy sources of the future. − Within fuel cells, direct methanol fuel cells (DMFC) have attracted significant attention due to the easy storage and transportation of methanol. , …”