Ionic liquids-noncovalently functionalized multi-walled carbon nanotubes decorated with palladium nanoparticles: A promising electrocatalyst for ethanol electrooxidation

A new palladium-based electrocatalyst (Pd/PDIL-MWCNTs) with ionic liquids molecules derived from 3,4,9,10-perylene tetracarboxylic acid (PDIL) noncovalently functionalized multi-walled carbon nanotubes (PDIL-MWCNTs) decorated with palladium nanoparticles is fabricated through a facile and surfactant-free synthetic technique. Due to the introduction of PDIL molecules, the Pd/PDIL-MWCNTs remarkably possesses smaller mean nano particles (NPs) size, better distribution of Pd NPs and larger electrochemical active surface area than the Pd NPs immobilized on the MWCNTs and the harsh acid treated MWCNTs (AO-MWCNTs). Furthermore, the Pd/PDIL-MWCNTs exhibits the enhanced electrocatalytic activity and improved stability for ethanol electrooxidation compared with Pd/MWCNTs and Pd/A0-MWCNTs, owing to the role of PDIL functional molecules. Additionally, a possible synergistic mechanism of PDIL-MWCNTs and Pd NPs for ethanol electrooxidation is also proposed on the basis of the previous literatures and the experimental results. The results indicate that the PDIL-MWCNTs is a promising support for electrocatalyst and the Pd/PDIL-MWCNTs catalyst may be a well candidate for direct ethanol alkaline fuel cells. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.