Yifan Ye

Renewable‐powered water electrolysis is pivotal to sustainable hydrogen production, yet the alkaline hydrogen evolution reaction (HER) remains kinetically sluggish at high current densities. This limitation stems not only from the extra water‐dissociation step, but also from an unfavorable interfacial water microenvironment that hampers charge transport—challenges that become even more pronounced at ultralow noble‐metal loadings. Herein, an ultralow‐loading PtRu alloy nanocluster catalyst on heterophase MoO _x (PtRu/MoO _x ) synthesized by ultrafast flash Joule heating (FJH) is reported. This nonequilibrium thermal shock drives PtRu alloying, preserves a defect‐rich interface, and establishes a pronounced electronic metal‐support interaction (EMSI) that renders the alloy surface electron‐deficient. Operando spectroscopy and density functional theory (DFT) calculations reveal that this electron‐deficient surface strengthens water adsorption, balances water dissociation with intermediate conversion, and promotes the evolution of interfacial water from isolated, cation‐dominated motifs into a surface‐coupled, hydrogen‐bond‐connected network. Consequently, PtRu/MoO _x requires only 56.15 mV to reach 100 mA cm ⁻² in 1 M KOH; as the cathode in an anion exchange membrane water electrolyzer, it achieves 1.836 V at 1.0 A cm ⁻² and operates stably for over 2000 h at 0.5 A cm ⁻² . This work provides a viable strategy for ultralow‐loading cathodes by synergistically coupling alloying‐governed reaction energetics with interfacial‐water microenvironment engineering.

The Hefei Advanced Light Facility, as a cutting-edge fourth-generation synchrotron radiation light source in the low-energy region, is scheduled for completion in 2028. Among the 10 beamlines of Phase I, the high-flux tender X-ray in situ/operando X-ray spectroscopy (BL 08) has been conceived as a wide-energy-coverage spectroscopy beamline. This beamline covers an energy range of 0.7–10 keV and integrates multiple X-ray spectroscopic techniques, including X-ray photoelectron spectroscopy (XPS), ambient-pressure X-ray photoelectron spectroscopy (APXPS), and X-ray absorption/emission spectroscopy (XAS/XES). BL 08 is designed to advance experimental capabilities, including resolution in the spatial, temporal, and energy dimensions, as well as in situ/operando measurements under relevant operating conditions. It enables chemical- and electronic-state characterization of complex multiphase interfaces relevant to batteries, catalysis, environmental science, semiconductors, etc. BL 08 provides a powerful complement to established X-ray spectroscopic methods, meeting the growing demand for advanced characterization with expanded energy, temporal, and spatial domains.

All-solid-state lithium–sulfur batteries (ASSLSBs) can overcome polysulfide shuttle problem and offer an economic, high-energy-density solution for next-generation energy storage. However, its solid-phase reaction mechanism remains unclear due to complex multiphase evolution, which is difficult to analyze using existing operando methods. Here, we design an in-situ cell enabling real-time sulfur K-edge X-ray absorption spectroscopy under practical conditions. Meanwhile, to address the complexity in spectra analysis, we introduce a hybrid method combining principal component analysis and constrained optimization, allowing robust quantitative spectral deconvolution despite severe peak overlap. Our results reveal a two-step discharge pathway: sulfur directly reduces to Li2S2 and then to Li2S. Additionally, we found that a P2S5 additive can react in-situ with Li2S to form the solid electrolyte Li3PS4, enhancing ionic conduction and promoting more complete discharge. This work establishes a general framework for real-time analysis of multiphase evolution during an electrochemical process and elucidates sulfur redox mechanisms in ASSLSBs.

The intermediate adsorption on single‐atom sites critically governs the catalytic performance of single‐atom catalysts. Site‐specific single atoms exhibit distinct intrinsic properties that modulate their intermediate adsorption behaviors. Herein, we elucidate the site‐dependent hydrogen adsorption of Pt single atoms by anchoring them at oxygen vacancies (Pt _V /CoOOH), three‐fold hollow sites (Pt _T /CoOOH), and lattice sites (Pt _L /CoOOH), respectively. Electrochemical measurements demonstrate Pt _T /CoOOH achieves an overpotential of 8 mV at a current density of 10 mA cm ⁻² and long‐term stability for 1000 h. Anion exchange membrane water electrolyzer (AEMWE) integrated Pt _T /CoOOH just required 1.90 V to reach the industrial current density of 1.0 A cm ⁻² with 1000 h stability time. In situ/operando x‐ray absorption fine structure (XAFS), ambient pressure x‐ray photoelectron spectroscopy (AP‐XPS), attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS), and theoretical calculations collectively demonstrate that Pt _T /CoOOH exhibits moderate H ₂ O dissociation kinetics and near‐thermoneutral hydrogen binding energy. The optimal hydrogen adsorption facilitated a balanced H adsorption‐H ₂ desorption kinetics, thereby contributing to a superior alkaline hydrogen evolution reaction (HER) activity compared to Pt _V /CoOOH with weaker hydrogen adsorption and Pt _L /CoOOH with stronger hydrogen adsorption. This work proposes a precise synthesis strategy to anchor single atoms at diverse sites and elucidates the influence of site‐dependent intermediate adsorption on catalytic performance.

The intermediate adsorption on single‐atom sites critically governs the catalytic performance of single‐atom catalysts. Site‐specific single atoms exhibit distinct intrinsic properties that modulate their intermediate adsorption behaviors. Herein, we elucidate the site‐dependent hydrogen adsorption of Pt single atoms by anchoring them at oxygen vacancies (Pt _V /CoOOH), three‐fold hollow sites (Pt _T /CoOOH), and lattice sites (Pt _L /CoOOH), respectively. Electrochemical measurements demonstrate Pt _T /CoOOH achieves an overpotential of 8 mV at a current density of 10 mA cm ⁻² and long‐term stability for 1000 h. Anion exchange membrane water electrolyzer (AEMWE) integrated Pt _T /CoOOH just required 1.90 V to reach the industrial current density of 1.0 A cm ⁻² with 1000 h stability time. In situ/operando x‐ray absorption fine structure (XAFS), ambient pressure x‐ray photoelectron spectroscopy (AP‐XPS), attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS), and theoretical calculations collectively demonstrate that Pt _T /CoOOH exhibits moderate H ₂ O dissociation kinetics and near‐thermoneutral hydrogen binding energy. The optimal hydrogen adsorption facilitated a balanced H adsorption‐H ₂ desorption kinetics, thereby contributing to a superior alkaline hydrogen evolution reaction (HER) activity compared to Pt _V /CoOOH with weaker hydrogen adsorption and Pt _L /CoOOH with stronger hydrogen adsorption. This work proposes a precise synthesis strategy to anchor single atoms at diverse sites and elucidates the influence of site‐dependent intermediate adsorption on catalytic performance.

Grain boundary induced tensile strain tunes catalyst oxophilicity, thereby reorganizing interfacial water and accelerating proton and water transfer to break the kinetic pH effect in HER.

Driving the oxygen evolution reaction (OER) through an oxide‑path mechanism (OPM) offers an appealing route to achieve simultaneously high activity and durability, yet rational modulation of dual‑metal active sites remain elusive. Here, we realize an unprecedented switch from the conventional adsorbate evolution mechanism (AEM) to OPM in 6H‐SrIrO ₃ via partial La substitution. Electronic structure analysis reveals that La incorporation strengthens electronic coupling across face‐sharing IrO ₆ dimers via Ir–O–Ir bridge. Consequently, these dimers, characterized by short Ir–Ir interatomic distances, are activated as dual‐metal centers that enable oxygen radical coupling via the OPM pathway. Benefiting from this mechanistic transition, the optimized 2%La–SrIrO ₃ catalyst surpasses the activity–stability trade‑off, exhibiting a low overpotential and exceptional durability over 1900 h at 1 A cm ⁻² in a proton exchange membrane (PEM) electrolyzer. This work unveils a mechanistic design paradigm for robust OER electrocatalysts operating under acidic conditions.

Single-atom catalysts (SACs) have emerged as transformative materials in heterogeneous electrocatalysis, yet their conventional symmetric coordination environments often yield suboptimal catalytic efficacy. This review systematically examines the deliberate disruption of local symmetry as a powerful design strategy to precisely tailor the electronic properties of SACs. We categorize and analyze atomic-level modulation approaches, including strain-induced lattice distortion, defect-engineered coordination tailoring, and curvature-derived interfacial fields, demonstrating how these strategies effectively break the intrinsic symmetry of motifs such as M–N₄. Our analysis reveals that such symmetry breaking redistributes electron density around the metal center, lifts orbital degeneracy, and optimizes the d-band center, leading to enhanced intermediate adsorption, accelerated reaction kinetics, and broken scaling relationships. Furthermore, these asymmetrically configured SACs exhibit improved stability through strengthened metal–support interactions. While significant progress has been made, we conclude that future efforts must address the challenges of atomic-level precision, stability under operation, and scalable synthesis to fully realize the potential of symmetry-broken SACs across various electrocatalytic applications, thereby establishing a new paradigm for the rational design of advanced electrocatalytic materials.

Optimizing the microenvironment of active sites is crucial for enhancing the catalytic activity of the hydrogen evolution reaction (HER) across various pH conditions. Here, guided by theoretical predictions of boron (B)-doping's electronic buffering effect on ruthenium (Ru) at the atomic scale, a highly efficient and universal-pH Ru-based HER electrocatalyst (Ru-NBC) by introducing B and nitrogen (N) into a carbon (C) matrix was designed. The Ru-NBC catalyst demonstrated exceptional HER activity, requiring overpotentials of 27, 40, and 68 mV in 1 M KOH, 0.5 M H₂SO₄, and 1 M phosphate buffer solution (PBS), respectively, to achieve a current density of 10 mA cm^-2. In situ Raman spectroscopy, ambient-pressure X-ray photoelectron spectroscopy, and potential of zero charge measurements revealed that B-doping modulates the local Ru microenvironment, restructuring the distribution balance of the interfacial water hydrogen-bond network within the electrochemical double layer and thereby facilitating water adsorption and dissociation. Density functional theory calculations further verified that the electronic buffering effect of B optimizes hydrogen adsorption in acidic media and water activation in alkaline conditions, resultantly contributing to the universal-pH HER performance. This study could provide guidance for the design of advanced electrocatalysts through modulation of the local microenvironment of active sites for energy storage and conversion.

The electrochemical reduction of carbon dioxide (CO₂) to methane (CH₄) presents a promising solution for mitigating CO₂ emissions while producing valuable chemical feedstocks. Although single‐atom catalysts have shown potential in selectively converting CO₂ to CH₄, their limited active sites often hinder the realization of high current densities, posing a selectivity‐activity dilemma. In this study, we developed a single‐atom cobalt (Co) doped copper catalyst (Co₁Cu) that achieved a CH₄ Faradaic efficiency exceeding 60 % with a partial current density of −482.7 mA cm⁻². Mechanistic investigations revealed that the incorporation of single Co atoms enhances the activation and dissociation of H₂O molecules, thereby lowering the energy barrier for the hydrogenation of *CO intermediates. In situ spectroscopic experiments and density functional theory simulations further demonstrated that the modulation of the *CO adsorption configuration, with stronger bridge‐binding, favours deep reduction to CH₄ over the C−C coupling or CO desorption pathways. Our findings underscore the potential of Co₁Cu catalysts in overcoming the selectivity‐activity trade‐off, paving the way for efficient and scalable CO₂‐to‐CH₄ conversion technologies.