Reconfiguration of Localized Ruthenium Surface via Incorporating Single Platinum Atoms for Favorable Hydrogen Oxidation Catalysis

초록

Despite the fact that only 2% of active sites can satisfy hydrogen oxidation reaction (HOR) activity thanks to fast kinetics, the fuel cell anode is still dependent on catalysts with large amounts of platinum (Pt). Herein, a minimal-cost ruthenium catalyst bearing ultralow quantities of Pt single atoms (RuPtSA) is developed to provide a high catalytic activity and tolerance to impurities as well as breakthrough reduction in Pt loading amounts. By introducing 1 wt.% Pt as a galvanic replacement for the Ru lattice, the active sites for the adsorption/desorption of hydrogen and CO are redefined. Ru acts both as an electron donor to Pt and as a host for OH groups, thereby accelerating the catalytic process. Using 1 wt.% Pt atoms, the HOR activity and CO resistance of Ru/C are improved, and the HOR mass activity of RuPtSA/C is 25.4-fold higher than that of Pt/C. Synergy between Ru and Pt is demonstrated by density functional theory calculations and verified using practical single-cell evaluations. Furthermore, RuPtSA/C exhibits an 18.4-fold higher mass activity than Pt/C in the HOR of an anion exchange membrane fuel cell, indicating its promise for use as a universal fuel cell anode catalyst.

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