1 Institute of Chemical Engineering, Biotechnology and Environmental Technology, Faculty of Engineering, SDU2 NanoMaterials Group, Department of Applied Physics, School of Science, Aalto University, Puumiehenkuja 2, 02150 Espoo, Finland3 Department of Physics, Chemistry and Pharmacy, Faculty of Science, SDU4 CIDETEC-IK4-Centre for Electrochemical Technologies, Paseo Miramón 196, E-20009 Donostia-San Sebastián, Spain5 Institute of Chemical Engineering, Biotechnology and Environmental Technology, Faculty of Engineering, SDU6 Department of Physics, Chemistry and Pharmacy, Faculty of Science, SDU
A non-covalent functionalization for multi-walled carbon nanotubes has been used as an alternative to the damaging acid treatment. Platinum nanoparticles with similar particle size distribution have been deposited on the surface modified multi-walled carbon nanotubes. The interaction between platinum nanoparticles and multi-walled carbon nanotubes functionalized with 1-pyrenecarboxylic acid is studied and its electrochemical stability investigated. This study reveals the existence of a platinum-support interaction and leads to three main conclusions. First, the addition of 1-pyrenecarboxylic acid is improving the dispersion of platinum nanoparticles, leading to an improved electrochemical activity towards oxygen reduction reaction. Second, the investigations regarding the electrochemical stability showed that the platinum-support interaction plays an important role in improving the long-term stability by as much as 20%. Third, post-mortem microscopy analysis showed a surprising effect. During the electrochemical stability investigations concerned with carbon corrosion it was found that the multi-walled carbon nanotubes were undergoing severe structural change, transforming finally into carbon spheres.