Highly-selective Synthesis of Trimetallic PtRuCu Nanoframes as Robust Catalysts for Methanol Oxidation Reaction

Multimetallic nanoframes (NFs) with large specific area and unsaturated coordination sites showed superior catalytic performance in electrochemical catalysis. Herein, we synthesized robust trimetallic PtRuCu NFs in high shape selectivity via preferential etching of Cu in PtRuCu nanoparticles (NPs) by nitrosonium tetrafluoroborate (BF4NO). As for as we know, this is the first time that BF4NO has been used as an etching reagent. The PtRuCu NFs/C exhibited superior mass activity and specific area activity over commercial Pt/C towards methanol oxidation reaction (MOR) due to the large specific area, high-density low-coordinated sites of frame nanostructures and the synergistic effect of the trimetallics. Moreover, the PtRuCu NFs/C also showed higher catalytic activity than the similar NFs obtained by acetic acid (HAc) as the etching reagent. We attributed the better performance to the fact that BF4NO was not only an etching-agent but also a ligand exchange reagent that could remove the olamine ligands on the catalyst surface, thus releasing more catalytic sites to improve catalytic performance.