An Electrocatalyst Based on Carbon Nanotubes Coated with Poly(vinylpyrrolidone) Shows a High Tolerance to Carbon Monoxide in a Direct Methanol Fuel Cell

Abstract We describe a facile method to enhance the CO tolerance of a fuel‐cell electrocatalyst dramatically based on carbon nanotubes. The electrocatalyst is composed of Pt deposited on carbon nanotubes wrapped in poly[2,2′‐(2,6‐pyridine)‐5,5′‐bibenzimidazole] (PyPBI) further covered by poly(vinylpyrrolidone) (PVP) through multipoint hydrogen bonding interactions between the PyPBI and PVP. The PVP‐coated electrocatalyst showed a ∼10 times higher CO tolerance compared to the non‐PVP‐coated electrocatalyst under a high (4 m) methanol concentration. Additionally, the PVP‐coated electrocatalyst showed an enhancement in the Pt stability because of the stabilization of the Pt‐NP by the PyPBI and PVP. After the durability test, the PVP‐coated electrocatalyst still showed ∼8 times higher CO tolerance because of the presence of the PVP bound stably with PyPBI. This study provides useful information for the design and fabrication of a state‐of‐the‐art anodic electrocatalyst for direct methanol fuel cells.