High-selective and effective carbon nanotubes supported ultrasmall PtPdRh electrocatalysts for ethanol oxidation

Abstract

Pt as the most effective ethanol oxidation reaction (EOR) catalyst confronts the problems of insufficient activity, unsatisfactory selectivity and poisoning by intermediates. It hindered the practical use of direct ethanol fuel cells (DEFCs). Therefore, in this work, carbon nanotubes (CNTs) supported ultrasmall PtPdRh nanoparticles (PtPdRh/CNTs, ∼2.3 nm) were synthesized with polyallylamine hydrochloride and hexadecyl trimethyl ammonium bromide for EOR. Pd as the core may reduce the cost, and Rh is helpful to cleave C−C bond. The introduction of Pd and Rh further brings about synergetic effect and adjustment of electronic structures. Moreover, partially oxidized PtPdRh nanoparticles is favorable to generate *OH species in alkaline media to accelerate intermediates removal. Benefit from the nanostructures, the mass and specific activities of PtPdRh/CNTs (1345.16 mA·mg−1 and 1.37 mA·cm−2) are higher than both commercial Pt/C and corresponding mono-/bi-metal catalysts. PtPdRh/CNTs also exhibit excellent selectivity and anti-poisoning ability, with jf/jb as high as 6.17, larger than most up-to-date reports. Besides, PtPdRh/CNTs own excellent stability and durability. This study adopting a rational design strategy to fabricate high-selective and effective EOR catalysts is conducive to the practical application of DEFCs.