Stable CO anti-poisoning and high durability of a Pt electrocatalyst supported on carbon nanotubes

Abstract

Stable CO anti-poisoning and high durability of an anodic electrocatalyst are very important for direct methanol fuel cells (DMFCs). Here, we report a Pt electrocatalyst with stable CO tolerance and high durability, in which Pt nanoparticles were homogeneously deposited on poly(vinylpyrrolidone) wrapped carbon nanotubes and the Pt nanoparticles were further coated with poly(2,5-benzimidazole) (ABPBI) via in situ polymerization. Although the electrochemical surface area (ECSA) and methanol oxidation reaction (MOR) activity decreased by ∼13% after coating the ABPBI layer on the Pt nanoparticles, the durability was dramatically enhanced due to the presence of ABPBI, which decelerates the Pt migration and aggregation. Meanwhile, the introduction of ABPBI to the electrocatalyst results in high and stable CO tolerance. After a durability test, the CO oxidation peak of the ABPBI coated electrocatalyst was almost stable (only 12 mV shift) compared to those of commercial (96 mV) and non-coated (108 mV) electrocatalysts. Thus, ABPBI is of importance to improve the durability and maintain stable CO tolerance of an electrocatalyst.