Amorphous nickel coating on carbon nanotubes supported Pt nanoparticles as a highly durable and active electrocatalyst for methanol oxidation reaction

Abstract

Multi-walled carbon nanotubes (CNTs) modified with amorphous nickel coating was reported as a novel support for platinum (Pt) for methanol oxidation reaction (MOR). First, an amorphous nickel coating on pristine CNTs (Ni/CNTs) via a simplified electroless deposition method without sensitization and activation is easily developed. Then, Pt nanoparticles (10 wt%) supported on Ni/CNTs (Pt/Ni/CNTs) were fabricated using a microwave-assisted reduction method. The as-prepared Pt/Ni/CNTs electrocatalyst exhibited higher electrocatalytic activity towards MOR in acidic solution, supported by the fact that its methanol oxidation current density was about 0.38 fold higher than that value of Pt/CNTs. Additionally, the proposed Pt electrocatalyst showed a little better electrocatalytic activity than the Pt/C catalyst containing Pt up to about 20%. Moreover, the Pt/Ni/CNTs also exhibited the best stability during the process of MOR. The improved activity and durability of Pt/Ni/CNTs electrocatalyst can be attributed to a more uniform distribution of Pt nanoparticles as well as the synergistic effect between Pt and amorphous nickel coating. Therefore, the as-prepared Pt/Ni/CNTs electrocatalyst is active and stable, which may be applied to the direct methanol fuel cells with high performance.