ACS_Nano Letters
February 11, 2026
Volume 26, Issue 5
Pages 1599-1974
Ultrathin PtCu Nanosheets: A New Frontier in Highly Efficient and Durable Catalysts for the Oxygen Reduction Reaction
SangJae LeeHyunWoo J. YangHyunWoo ChangJunu BakDongWon ShinEunAe Cho*
Platinum–copper alloy nanosheets supported on carbon (PtCu NS/C) with well-defined (111) facets were synthesized via a scalable one-pot method, yielding ultrathin structures with thicknesses of ∼1 nm and lateral sizes of ∼10–15 nm. As catalysts for the oxygen reduction reaction (ORR), PtCu NS/C exhibited superior performance and durability compared to those of PtCu octahedral nanoparticles (PtCu NP/C) and commercial Pt/C. In half-cell measurements, PtCu NS/C achieved a mass activity of 5.61 A mgPt–1 at 0.9 VRHE and an electrochemically active surface area (ECSA) of 94 m2 gPt–1, significantly surpassing those of PtCu NP/C and Pt/C. In polymer electrolyte membrane fuel cells (PEMFCs), PtCu NS/C delivered a current density of 48 mA cm–2 at 0.8 V, retaining 31 mA cm–2 after 50 000 accelerated stress test cycles. The outstanding activity and stability are attributed to the nanosheet architecture, which provides a high surface-to-volume ratio, abundant (111) surface atoms, enhanced Pt utilization, and an enlarged interfacial contact region with the carbon support. These findings highlight the potential of two-dimensional PtCu nanosheets as highly efficient and durable ORR catalysts for PEMFCs.
Image created by minjeong Kim / Nanosphere
ACS_Nano Letters
February 11, 2026
Volume 26, Issue 5
Pages 1599-1974
Ultrathin PtCu Nanosheets: A New Frontier in Highly Efficient and Durable Catalysts for the Oxygen Reduction Reaction
SangJae LeeHyunWoo J. YangHyunWoo ChangJunu BakDongWon ShinEunAe Cho*
Platinum–copper alloy nanosheets supported on carbon (PtCu NS/C) with well-defined (111) facets were synthesized via a scalable one-pot method, yielding ultrathin structures with thicknesses of ∼1 nm and lateral sizes of ∼10–15 nm. As catalysts for the oxygen reduction reaction (ORR), PtCu NS/C exhibited superior performance and durability compared to those of PtCu octahedral nanoparticles (PtCu NP/C) and commercial Pt/C. In half-cell measurements, PtCu NS/C achieved a mass activity of 5.61 A mgPt–1 at 0.9 VRHE and an electrochemically active surface area (ECSA) of 94 m2 gPt–1, significantly surpassing those of PtCu NP/C and Pt/C. In polymer electrolyte membrane fuel cells (PEMFCs), PtCu NS/C delivered a current density of 48 mA cm–2 at 0.8 V, retaining 31 mA cm–2 after 50 000 accelerated stress test cycles. The outstanding activity and stability are attributed to the nanosheet architecture, which provides a high surface-to-volume ratio, abundant (111) surface atoms, enhanced Pt utilization, and an enlarged interfacial contact region with the carbon support. These findings highlight the potential of two-dimensional PtCu nanosheets as highly efficient and durable ORR catalysts for PEMFCs.
Image created by minjeong Kim / Nanosphere