The carbon nanotube (CNT) has unique electrical and structural properties due to it's sp(2)pi-conjugative structure that leads to the higher electrocatalysis. The pi-conjugative structure, that allows the CNT interact with various compounds and metal nanoparticles (NPs) through pi-pi electronic interaction. However, the damage of pi-conjugative sidewall of CNT that can be hinder the electrocatalytic activity has found. For this study, the CNT, as base material, has been prepared through a conventional acid treatment method up to 15 h; the higher degree of sidewall damage has been observed in last 5 h during treatment period. The short and long term acid treated (denoted as CNT and CNT COOH, respectively) CNTs have been subsequently fabricated with palladium NPs (denoted as CNT/Pd and CNT-Pd, respectively) and employed as ethanol oxidation reaction (EOR) catalysts. The CNT-Pd displays a poor electrocatalytic performance towards EOR than that of CNT/Pd due to the damage of pi-conjugative sidewall. The kinetic parameters including poisoning tolerance have also been hampered by the surface damage. The CNT/Pd (similar to 3.3 folds) and CNT Pd (similar to 1.5 folds) are express higher electrocatalytic activity and poisoning tolerance than that of Pd/C while Pd mass loading remains in the same amount. (C) 2015 Elsevier B.V. All rights reserved.