Kepeng Song

The development of stable and selective electrocatalysts for hydrogen peroxide (H ₂ O ₂ ) synthesis via the two‐electron oxygen reduction reaction (2e ⁻ ORR) is critical for sustainable green chemistry. However, the performance of transition metal oxides (TMOs) is often severely limited by the thermodynamic tendency to expose crystal planes with sluggish kinetics. Herein, we present a doping‐mediated crystal‐plane‐engineering strategy to overcome these constraints, using Ti ₂ O ₃ as a model system. Guided by a d ‐orbital morphology descriptor, we identified specific crystal planes, including (012) and (113)/(104), as theoretically active sites. Experimentally, Ni doping acted as an effective crystal‐plane‐directing agent, successfully modulating surface energies to induce the synergistic exposure of these target planes. Consequently, the optimized Ni‐Ti ₂ O ₃ electrocatalyst delivered an H ₂ O ₂ selectivity (94.4%) and yield of 2.56 mol g _cat ⁻¹ h ⁻¹ at 0.4 V vs. RHE. This work demonstrates the efficacy of orbital‐driven plane control, providing a generic paradigm for the rational design of high‐performance TMO electrocatalysts for advanced energy applications.

Efficient electrocatalytic ammonia synthesis has been achieved by a doped correlated oxide (Mo-Ti ₂ O ₃ ) at ambient conditions.

Recently, high‐endurance ferroelectric HfO ₂ is highly desirable since the emerging of in‐memory computing requires non‐volatile memories not only to store data but also to execute computation, challenging writing/erasure switching reliability. Understanding and exploitation of the polarization fatigue diagram are crucial for improving endurance performances. Here, we show fatigue‐resistant Sm:HfO ₂ thin films by modulating grain boundaries (GBs) in orientation‐controllable orthorhombic phase. On GBs, orientation discontinuity raises energy levels of O 2 p orbitals due to lattice distortion, which promote electron accumulation and yield a high‐symmetry structural transform at the boundary, facilitating 90° switching of out‐of‐plane domains because of lowered switching barrier. Then the domains are frozen in plane by the charged GBs and polarization fatigue takes place. By eliminating GBs associated with phase transform, remarkably‐improved fatigue resistance is achieved in uniform 180° switching, which exhibits the increase of fatigue‐free endurance by 200 times to 2.0 × 10 ⁹ cycles with, more importantly, a large field‐cycling non‐volatile polarization of ∼60 µC/cm ² , showing the state‐of‐the‐art endurance performances in hafnium oxides. Roadmaps of the fatigue scenarios are given based on key roles of GBs in domain configurations and switching pathways. Our findings open a new perspective for fatigue studying and guide the material design of high‐reliability hafnium oxide memories.

La _{3‐ x} Te ₄ materials are ideal candidates for next‐generation radioisotope thermoelectric generators due to their excellent thermoelectric performance and high‐temperature stability. For decades, researchers have used substitutional doping or vacancy modulation to tune carrier concentration, but these methods can only tune it without optimizing the conduction band structure or suppressing lattice thermal conductivity. Interstitial doping strategy breaks this deadlock by enabling simultaneous electronic and thermal regulation without mutual interference. Herein, a series of Cu‐doped La _2.74 Cu _x Te ₄ ( x = 0, 0.01, 0.05, 0.1, 0.15) samples were synthesized. Cu incorporation elevates the Seebeck coefficient without degrading significantly the power factor, while simultaneously suppressing lattice thermal conductivity via anharmonic vibrational behavior that strengthens low‐frequency acoustic phonon modes and intensifies phonon‐phonon scattering. Among the synthesized compositions, La _2.74 Cu _0.05 Te ₄ achieves a peak thermoelectric figure of merit of 1.58 at 1073 K, representing a 34% improvement over the undoped La _2.74 Te ₄ . Furthermore, the material exhibits a notable average zT value of 1.5 within the operational temperature range of 873–1073 K. When compared to the previously reported state‐of‐the‐art lanthanum telluride‐based thermoelectrics, this represents a significant improvement of 71.3% in the average zT value.

La _{3‐ x} Te ₄ materials are ideal candidates for next‐generation radioisotope thermoelectric generators due to their excellent thermoelectric performance and high‐temperature stability. For decades, researchers have used substitutional doping or vacancy modulation to tune carrier concentration, but these methods can only tune it without optimizing the conduction band structure or suppressing lattice thermal conductivity. Interstitial doping strategy breaks this deadlock by enabling simultaneous electronic and thermal regulation without mutual interference. Herein, a series of Cu‐doped La _2.74 Cu _x Te ₄ ( x = 0, 0.01, 0.05, 0.1, 0.15) samples were synthesized. Cu incorporation elevates the Seebeck coefficient without degrading significantly the power factor, while simultaneously suppressing lattice thermal conductivity via anharmonic vibrational behavior that strengthens low‐frequency acoustic phonon modes and intensifies phonon‐phonon scattering. Among the synthesized compositions, La _2.74 Cu _0.05 Te ₄ achieves a peak thermoelectric figure of merit of 1.58 at 1073 K, representing a 34% improvement over the undoped La _2.74 Te ₄ . Furthermore, the material exhibits a notable average zT value of 1.5 within the operational temperature range of 873–1073 K. When compared to the previously reported state‐of‐the‐art lanthanum telluride‐based thermoelectrics, this represents a significant improvement of 71.3% in the average zT value.

Electrocatalytic reduction of CO₂ to CH₄ is a promising strategy for converting renewable energy into a desirable high-energy-density fuel with significant compatibility with the existing natural gas infrastructure. However, conventional alkaline and neutral CO₂-to-CH₄ systems exhibit low carbon utilization due to the loss of CO₂ into (bi)carbonate. Conducting CO₂ electroreduction in acid can alleviate carbonation issues but suffers from moderate CH₄ selectivity owing to competing hydrogen evolution. Herein, we report that thiocyanate (SCN^-), a well-known poison in electrocatalysis, can remarkably enhance acidic electrocatalytic CO₂-to-CH₄ performance, specifically resulting in a record-high CH₄ Faradaic efficiency of 81.8% (accompanied by a CH₄ partial current density of 213.3 mA cm^-2) and a single-pass carbon efficiency of 65.2% when using a CeO₂-supported Cu single-atom material as the model catalyst. We demonstrate that SCN^- enables the coordination with Cu single sites, forming the SCN^--stabilized Cu^(I) species, which effectively suppresses the competing hydrogen evolution reaction and, more importantly, manipulates the binding of *CHO to promote its protonation to *CHOH, thereby leading to selective and efficient CH₄ production. This work highlights the unique role of thiocyanate in promoting the selective reduction of CO₂ to CH₄ and offers insights into the design of surface chemistry for precise regulation of catalytic processes to achieve targeted product production.

The production of monophenols from lignocellulose with cellulose intact without exogenous hydrogen via self-hydrogen supplied fractionation is promising, yet requires high metal loadings and yields saturated products. Herein, we report a single-atom alloyed Pt₁Ni catalyst that achieves 50.9 wt% yield of phenolic monomers from birch sawdust with about 50% selectivity to valuable propenyl side-chained products under mild conditions (140 °C, 1 atm N₂), while preserving cellulose intact. Reaction pathway studies and density functional theory calculations based on a β-O-4 model compound reveal three coexisting pathways. The Pt₁Ni alloy preferentially promotes the dehydroxylation of C_α-OH and forms a key C_α = C_β intermediate due to the oxygen affinity of Ni sites, and ultimately, enhance the production of valuable propenyl products via the synergistic effect of Pt and Ni. This work provides a strategy for maximizing Pt utilization and producing unsaturated chemicals from biomass under hydrogen-free conditions, advancing sustainable biorefining.

Photoelectrochemical (PEC) solar-driven conversion of waste biomass into value-added chemicals offers a promising route toward sustainable development but remains limited by inefficient charge carrier utilization. Here, we rationally construct a spatially engineered NiAu heterodimer via a two-step deposition strategy guided by bond energy compatibility and lattice mismatch principles. The NiAu layer effectively modulates the interfacial barrier height, promoting carrier separation and transport while suppressing bulk recombination, while the introduction of glucose into the electrolyte facilitates hole injection at the photoanode/electrolyte interface. The synergistic optimization of the heterointerface architecture and electrolyte composition enables a record-low PEC oxidation onset potential of −0.20 V versus RHE. Further coupling with nitrite reduction on a Ru-doped Cu nanowire cathode achieves unbiased solar-driven synthesis of fructose and ammonia. This work establishes a generalizable interfacial–electrolyte coengineering framework to overcome carrier utilization bottlenecks, offering new opportunities for advancing high-efficiency, unbiased PEC platforms for solar chemical manufacturing.