Synergistically Mitigating Electron Back-Donation by Single-Atomic Fe-N-C and Alloying to Boost CO-Tolerance of Pt in Hydrogen Oxidation

Developing CO-tolerant Pt-based catalysts for the hydrogenoxidationreaction (HOR) is critical for the commercialization of fuel cellsand thus receiving increasing interest. Although it is known thatweakening the CO adsorption on Pt can improve CO tolerance, efficientstrategies are still needed. Inspired by theoretical simulations,we propose here a cascade strategy to synergistically mitigate electronback-donation of Pt 5d -> CO 2 pi* by introducing single-atomic Fe-N-C substrate andalloying, which significantly boosts the CO-tolerance of Pt-basedHOR catalysts. The obtained PtNiMo/Fe-N-C can maintainabove 80% HOR current density after 2000 s in 1000 ppm CO/H-2, substantially outperforming control catalysts and ranking amongthe state-of-the-art catalysts. The in situ surface-enhanced infraredadsorption spectroscopy validates that the effectively weakened COadsorption contributes to improved CO tolerance. This strategy opensup opportunities for designing advanced HOR catalysts with desiredCO tolerance.

Automated summary

Developing CO-tolerant Pt-based catalysts is critical for fuel cell commercialization. A cascade strategy of introducing single-atomic Fe-N-C substrate and alloying is proposed to mitigate electron back-donation and improve CO tolerance.