Surface and strain engineering are two effective strategies to improve performance; however, synergetic controls of surface and strain effects remains a grand challenge. Herein, we report a highly efficient and stable electrocatalyst with defect-rich Pt atomic layers coating an ordered Pt3Sn intermetallic core. Pt atomic layers enable the generation of 4.4% tensile strain along the [001] direction. Benefiting from synergetic controls of surface and strain engineering, Pt atomic-layer catalyst (Ptatomic‑layer) achieves a remarkable enhancement on ethanol electrooxidation performance with excellent specific activity of 5.83 mA cm–2 and mass activity of 1166.6 mA mg Pt –1, which is 10.6 and 3.6 times higher than the commercial Pt/C, respectively. Moreover, the intermetallic core endows Ptatomic‑layer with outstanding durability. In situ infrared reflection–absorption spectroscopy as well as density functional theory calculations reveal that tensile strain and rich defects of Ptatomci‑layer facilitate to break C–C bond for complete ethanol oxidation for enhanced performance.

The development of rapid and dependable proton transport channels is crucial for proton exchange membrane fuel cells (PEMFCs) operating in low humidity conditions. Herein, an NH-Zr framework rich in basic sites was in situ constructed in a perfluorosulfonic acid (PFSA) solution, and PFSA-NH-Zr hybrid proton exchange membranes were prepared. The introduced NH-Zr framework successfully induced proton conducting groups (-SO3H) reorganization along the NH-Zr framework, resulting in the formation of fast ion transport channels. Meanwhile, under low humidity, the acid-base pairs between N-H (NH-Zr framework) and -SO3H (PFSA) promoted the protonation/deprotonation and the subsequent proton leap via the Grotthuss processes. Especially, the hybrid membrane PFSA-NH-Zr-1 with suitable NH-Zr content had a promising proton conductivity of 0.031 S/cm at 80°C, 40% RH, and 0.292 S/cm at 80°C, 100% RH, which were approximately 33% and 40% higher than the pristine PFSA membrane (0.023 S/cm and 0.209 S/cm), respectively. In addition, the maximum power density of the hybrid proton exchange membrane was 0.726 W/cm2, which was nearly 20% higher than the pristine PFSA membrane (0.604 W/cm2) under 80°C, 40% RH. This work established a referable strategy for developing high-performance proton exchange membranes under low RH conditions.

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