Hongfang Du

Electrochemical nitrate reduction reaction (NO ₃ ⁻ RR) enables sustainable ammonia (NH ₃ ) production but is constrained by sluggish kinetics due to the high stability of NO ₃ ⁻ and insufficient hydrogenation of nitrogenous intermediates, where the initial NO ₃ ⁻ → NO ₂ ⁻ conversion is the rate‐determining step (RDS). Herein, we report a CuSn(OH) ₆ /Co heterostructure designed via an interfacial tandem‐catalysis strategy to address both the kinetic bottleneck and downstream hydrogenation steps in a coordinated manner. In this architecture, CuSn(OH) ₆ activates NO ₃ ⁻ and then selectively catalyzes its conversion into *NO ₂ , thereby overcoming the RDS limitation. Meanwhile, Co nanoparticles promote rapid H ₂ O dissociation to generate abundant *H for subsequent hydrogenation reactions. Further investigations reveal that the heterointerface enables efficient directional transfer of *NO ₂ intermediate from CuSn(OH) ₆ to the Co component, promoting its complete reduction to NH ₃ . Benefiting from this spatially and functionally integrated division of catalytic roles, the CuSn(OH) ₆ /Co heterostructure exhibits a high NH ₃ yield of 64.51 µmol h ^{− 1} mg _Cat ^{− 1} and a selectivity of 92.28% at −0.7 V in 0.1 M NaSO ₄ containing 10 mM NaNO ₃ , outperforming most reported catalysts. This work highlights a tandem‐catalysis strategy that synchronously regulates RDS and hydrogenation pathways for sustainable NH ₃ production via NO ₃ ⁻ RR.

A molten-salt-mediated quenching strategy is reported for composition-invariant tuning of lattice strain in transition-metal sulfides. RuS ₂ catalysts with tunable tensile strain are synthesized to investigate the strain and HER activity relationship.

The formation of metal–hydrogen intermediates (M─H*) is critical for the alkaline hydrogen evolution reaction (HER), but is kinetically hindered by the energy‐intensive water dissociation. Here, we report a distinct pathway in the model catalyst of Pt nanoparticles loaded on TiH _1.924 (Pt/TiH _1.924 ), which directly generates Pt─H* by transferring lattice hydrogen from TiH _1.924 to Pt catalytic sites, while the lattice hydrogen can be dynamically replenished by the electrolyte spontaneously. This pathway decouples Pt─H* formation from water dissociation at a significantly lower energy barrier, as evidenced by operando differential electrochemical mass spectrometry and in situ Raman spectroscopy. The continuous hydrogen supply from the hydride support enables the Pt/TiH _1.924 catalyst to achieve a 35.6‐fold higher mass activity than Pt/C at 100 mV overpotential. Moreover, in an anion exchange membrane water electrolyzer with Pt/TiH _1.924 as the cathode, the cell voltage only requires 1.76 V at a current density of 1 A cm ⁻² , and the device can operate stably for over 1000 h under this current density. This work proposes a lattice hydrogen‐mediated mechanism to boost alkaline HER and other electrochemical processes constrained by slow M─H* formation, by decoupling Pt─H* production from water dissociation using metal hydride supports.

The formation of metal–hydrogen intermediates (M─H*) is critical for the alkaline hydrogen evolution reaction (HER), but is kinetically hindered by the energy‐intensive water dissociation. Here, we report a distinct pathway in the model catalyst of Pt nanoparticles loaded on TiH _1.924 (Pt/TiH _1.924 ), which directly generates Pt─H* by transferring lattice hydrogen from TiH _1.924 to Pt catalytic sites, while the lattice hydrogen can be dynamically replenished by the electrolyte spontaneously. This pathway decouples Pt─H* formation from water dissociation at a significantly lower energy barrier, as evidenced by operando differential electrochemical mass spectrometry and in situ Raman spectroscopy. The continuous hydrogen supply from the hydride support enables the Pt/TiH _1.924 catalyst to achieve a 35.6‐fold higher mass activity than Pt/C at 100 mV overpotential. Moreover, in an anion exchange membrane water electrolyzer with Pt/TiH _1.924 as the cathode, the cell voltage only requires 1.76 V at a current density of 1 A cm ⁻² , and the device can operate stably for over 1000 h under this current density. This work proposes a lattice hydrogen‐mediated mechanism to boost alkaline HER and other electrochemical processes constrained by slow M─H* formation, by decoupling Pt─H* production from water dissociation using metal hydride supports.

Tunable cation vacancy engineering of FeP leads to a volcano-type HER activity trend. An optimal vacancy level of 16.2% maximizes active sites and *H adsorption for efficient HER, while excessive vacancies induce severe oxidation to impede the HER.

A series of asymmetrical spiro-type hole transporting materials (HTMs) was developed by precisely regulating the peripheral flexible diphenylamine and rigid carbazole fragments, which enabled a high efficiency of 25.21% in perovskite solar cells.