Synthesis of Ultrathin AuPt Alloy Porous Nanowires with Abundant Electrocatalytic Active Sites for Excellent Electrocatalysts

Abstract

Development of excellent fuel cells requires ingenious design and precise regulation of the structure and composition of catalysts. This report describes a facile method for preparing gold–platinum alloy porous nanowires (AuPt PNWs) with a tunable composition. This method employs uniform tellurium nanowires (Te NWs) as a sacrifice template and reductant in galvanic replacement reactions, followed by etching using NaClO. Due to the synergistic actions of the two metals and a well-designed structure containing abundant electrocatalytic active sites, the prepared AuPt PNWs showed excellent performance in electrochemical experiments using direct methanol fuel cells. The PNWs with the composition of Au28Pt72 exhibited the highest activities in the methanol solution, with a maximum mass current density of 1.278 A mg–1 (1.22 and 1.65 times that of Pt PNWs and commercial Pt/C, respectively). Besides, the Au28Pt72 PNWs revealed good stability by retaining 85.2% of its initial mass current density after 2000 cycles. The high electrocatalytic activity at optimal composition is attributed to a suitable binding energy of methanol on the catalyst surfaces, which is supported by density functional theory calculations. These findings present new pathways for the engineering and preparation of enhanced electrocatalytic performance electrocatalysts in direct methanol fuel cells.

Recent progress on the synthesis of metal alloy nanowires as electrocatalysts

“…23f and g). 171,172 Metal ions and polymeric fibres, including biological macromolecules that form linear assemblies in solution and electrospun nanofibers, 173,174 could assemble into 1D nanostructures and act as self-sacrificing templates to synthesize 1D alloy nanowires. [175][176][177][178][179] For instance, insulin amyloid fibrils (INSAFs) have been exploited to synthesize PtRh 180 PtRhPd 181 nanowires (Fig.…”