High CO and sulfur tolerant proton exchange membrane fuel cell anodes enabled by “work along both lines” mechanism of 2,6-dihydroxymethyl pyridine molecule blocking layer

Proton exchange membrane fuel cells (PEMFCs) are hindered by their poor tolerance to CO and H 2 S poisoning. Herein, we report an effective method, via engineering 2,6-dihydroxymethyl pyridine (DhmPy) molecule blocking layers on Pt surface, aiming to save the poisoning issue for PEMFC anode reaction. The PEMFCs assembled by this catalyst produce a power density of 1.18 W cm −2 @ 2.0 A cm −2 and 1.32 W cm −2 @ 2.0 A cm −2 , far exceeding commercial Pt/C after H 2 /10 ppm CO poisoning and H 2 /5 ppm H 2 S poisoning tests, respectively. Density functional theory (DFT) indicates that a coronal molecule layer with a steric confinement height (1.82 Å), constructed by DhmPy, emerges more intensive adsorption energy compared to 2,6-pyridinedicarboxamide (DcaPy) and 2,6-diacetylpyridine (DAcPy), thereby more effectively inhibits the adsorption of large-sized CO and H 2 S on Pt surface without affecting H 2 traverse. This “work along both lines” mechanism with the resistance of both CO and H 2 S provides a new and promising design thought for high CO and sulfur tolerant PEMFC anodes.