Kezhu Jiang

Precise phase engineering at the atomic scale is central to advanced catalyst design, yet controlling high-temperature phase transitions remains challenging because of large kinetic barriers. Here, we report a gas-pressure-induced strategy that establishes gas pressure as an independent dimension for nanoscale phase engineering. Mechanistic studies reveal that modulating the gas-phase diffusion coefficient via the gas pressure can control the structural evolution of crystal phases. As a demonstration of this methodology, an optimal pressure effectively overcomes high-temperature constraints and retards the escape of volatile species, enabling the precise construction of phase-pure ordered PdZn intermetallics. This strategy extends to ternary PdZnCu ordered alloys, inducing significant compressive strain while preserving the long-range ordered lattice. The resulting catalyst delivers a high oxygen reduction mass activity of 1.09 A mgPd–1 and long-term durability over 30 000 cycles. This gas-pressure-induced approach circumvents conventional thermodynamic and kinetic constraints, providing a pathway for the design of advanced intermetallic catalysts.

Suppressing the dissolution of transition metals in multi‐component platinum (Pt)‐based oxygen reduction reaction (ORR) catalysts is critical yet challenging for proton exchange membrane fuel cell (PEMFC). Herein, we employ a dual anchoring strategy of rare earth (RE) surface stabilization and metal‐nitrogen‐carbon (MNC) interaction with porous Pt‐nickel‐cobalt nanowires (PtNiCo PNWs) to achieve satisfactory ORR and membrane electrode assembly (MEA) performances. The single site and cluster of praseodymium (Pr) tune the Pt electronic structure and protect the Ni/Co sites from dissolution, while zinc‐N‐C (ZnNC) provides extra active sites and stronger anchoring effect, yielding 9.0/9.5 times higher than those of commercial Pt/C in ORR mass and specific activities. Furthermore, the MEA exhibits high peak power density of 2.33 W cm ⁻² , mass activity of 0.79 A mg _Pt ⁻¹ at 0.9 V _iR‐free and long‐term lifetime of operating 30000/90000 cycles with 8.2%/28.3% decay, further reflecting our reasonable design conception of Pt‐based ORR catalysts for PEMFC device.

Precise regulation of lattice strain in platinum (Pt)‐based intermetallic catalysts is essential for optimizing oxygen reduction reaction (ORR) performance, yet strain evolution during atomic ordering is often simplified as isotropic compression, masking its structural complexity. Herein, we systematically modulate the ordering degree of PtNi nanowires from 4.5% to 65.8% to dynamically track this structural evolution. A key finding that refines the conventional understanding of strain evolution is the emergence of characteristic biaxial strain during the disorder‐to‐order transition, which we quantitatively distinguish from the universally assumed isotropic compression model. Specifically, this transition induces in‐plane lattice expansion coupled with out‐of‐plane lattice contraction. As the ordering degree increases, this biaxial strain progressively relaxes the compressive stress on the catalytically active (111) surface, rather than amplifying it as traditional models predict. Density functional theory calculations confirm this anisotropic strain reduces the energy barrier of the rate‐determining *O protonation step from 0.51 to 0.39 eV. The optimized catalyst exhibits a mass activity of 1.30 A mg _Pt ⁻¹ with 86.0% retention after 60 000 cycles, and a peak power density of 1014.5 mW cm ⁻² in membrane electrode assemblies. This work identifies tunable ordering‐induced biaxial strain as a critical structural parameter for designing high‐performance Pt‐based ORR catalysts.

Precise regulation of lattice strain in platinum (Pt)‐based intermetallic catalysts is essential for optimizing oxygen reduction reaction (ORR) performance, yet strain evolution during atomic ordering is often simplified as isotropic compression, masking its structural complexity. Herein, we systematically modulate the ordering degree of PtNi nanowires from 4.5% to 65.8% to dynamically track this structural evolution. A key finding that refines the conventional understanding of strain evolution is the emergence of characteristic biaxial strain during the disorder‐to‐order transition, which we quantitatively distinguish from the universally assumed isotropic compression model. Specifically, this transition induces in‐plane lattice expansion coupled with out‐of‐plane lattice contraction. As the ordering degree increases, this biaxial strain progressively relaxes the compressive stress on the catalytically active (111) surface, rather than amplifying it as traditional models predict. Density functional theory calculations confirm this anisotropic strain reduces the energy barrier of the rate‐determining *O protonation step from 0.51 to 0.39 eV. The optimized catalyst exhibits a mass activity of 1.30 A mg _Pt ⁻¹ with 86.0% retention after 60 000 cycles, and a peak power density of 1014.5 mW cm ⁻² in membrane electrode assemblies. This work identifies tunable ordering‐induced biaxial strain as a critical structural parameter for designing high‐performance Pt‐based ORR catalysts.

Precise regulation of lattice strain in platinum (Pt)-based intermetallic catalysts is essential for optimizing oxygen reduction reaction (ORR) performance, yet strain evolution during atomic ordering is often simplified as isotropic compression, masking its structural complexity. Herein, we address this critical gap by systematically modulating the ordering degree of PtNi nanowires by hydrogen-mediated annealing, obtaining continuously tunable ordering from 4.5% to 65.8% without structural coarsening. A key finding that breaks with long-standing paradigms is the emergence of characteristic biaxial strain during the disorder-to-order transition, distinct from the universally assumed isotropic compression. Specifically, this transition induces in-plane lattice expansion coupled with out-of-plane lattice contraction; as ordering degree increases, this biaxial strain progressively relaxes the compressive stress on the catalytically active (111) surface, rather than amplifying it as traditional models predict. This anomalous strain evolution modulates the electronic structure of Pt, optimizing the Pt d-band center, resolving the core issue of disordered PtNi alloys with excessive compression, and weakening oxygen intermediate binding. The highly ordered PtNi nanowires deliver a mass activity of 1.30 A mg _Pt ^-1 and maintain nearly unchanged activity after 30,000 cycles for ORR, while achieving a peak power density of 1014.5 mW cm ^-2 in the membrane electrode assembly. This work identifies tunable ordering-induced biaxial strain as a critical structural parameter for designing high-performance Pt-based ORR catalysts.