Highly-selective synthesis of trimetallic PtRuCu nanoframes as robust catalysts for the methanol oxidation reaction

Abstract

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 with high shape selectivity via preferential etching of Cu in PtRuCu nanoparticles (NPs) with nitrosonium tetrafluoroborate (BF₄NO). As far as we know, this is the first time that BF₄NO has been used as an etching reagent. PtRuCu NF/C exhibited superior mass activity and specific area activity over commercial Pt/C towards the methanol oxidation reaction (MOR) due to the large specific area, high-density low-coordinated sites of the frame nanostructures and the synergistic effect of the trimetallics. Moreover, PtRuCu NFs/C also showed higher catalytic activity than the similar NFs obtained with 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 the catalytic performance.