Tailoring carbon nanotubes surface with maleic anhydride for highly dispersed PtRu nanoparticles and their electrocatalytic oxidation of methanol

Taking the direct Friedel-Crafts reaction between pristine carbon nanotubes (CNT) and maleic anhydride, we have developed a facile strategy for the synthesis of carboxylated-carbon nanotubes (CNT-C). The covalently grafted carboxyl groups on the CNT-C surface not only significantly improves its hydrophilicity, but also effectively anchors and stabilizes the PtRu nanoparticles. Transmission electron microscopy images reveal that PtRu nanoparticles with an average size of 3.3 nm are uniformly dispersed on the CNT-C surface. Electrochemical results demonstrate the PtRu/CNT-C nanohybrids obtained have a higher electrochemical surface area, electrocatalytic activity and better stability towards methanol oxidation when compared to PtRu nanoparticles supported on acid oxidized-CNT. This provides a facile approach to synthesize noble metal nanoparticles/CNT electrocatalysts for high performance energy conversion devices in the future.