Bernt Johannessen

Electrochemical C─N coupling of CO ₂ with nitrogen species offers a sustainable route to urea and related chemicals but is constrained under steady‐state electrolysis by mismatched reaction kinetics. Here, pulsed oxidative–reductive electrolysis temporally coordinates CO ₂ reduction and NH ₃ oxidation, regulating the generation and coexistence of carbon‐ and nitrogen‐derived intermediates. Co/CuNC, containing atomically dispersed Co and Cu sites within a nitrogen‐doped carbon (NC), achieves a total C─N faradaic efficiency of 42 ± 4%, dominated by urea (20 ± 2%) and ethyl urea (16 ± 2%), with respective yield rates (YR) of 295 ± 25 and 50 ± 5 mmol h ⁻¹ g _cat ⁻¹ . In situ synchrotron x‐ray absorption spectroscopy (XAS) reveals potential‐dependent changes in Cu and Co oxidation states and coordination environments, while in situ infrared spectroscopy identifies pulse‐regulated *CO and *NH _x intermediates and suggests concurrent electrochemical and Wöhler‐type pathways. Density functional theory calculations reveal complementary site functions: Cu favors *NH ₂ formation, whereas Co more strongly stabilizes *NH _x and *CO intermediates, with *CO also accessible at Cu sites. These findings establish temporal coordination of reactant activation, intermediate populations, and active‐site states as a mode‐enabled strategy for accessing higher‐order C─N products.

Aqueous Zn‐ion batteries (AZIBs) suffer severe degradation at subzero temperatures due to electrolyte freezing, sluggish Zn ²⁺ kinetics, and dendrite‐induced interfacial instability. Herein, a triple‐coupling regulation strategy integrating solvation structure, interfacial chemistry, and crystallographic orientation through a formamide‐ethanol deep eutectic electrolyte (ZEFW2) was developed. Molecular dynamics simulations and spectroscopic analyses reveal that ZEFW2 redistributes the primary Zn ²⁺ solvation environment, reducing H ₂ O and acetate coordination while introducing formamide coordination and maintaining favorable Zn ²⁺ transport. Depth‐resolved XPS further reveals a chemically reconstructed Zn interphase containing Zn‐O‐related inorganic species and persistent N‐ and C‐containing electrolyte‐derived species. The modified solvation and interfacial environments regulate Zn nucleation and promote preferential Zn deposition along the (101) facet, enabling more homogeneous Zn growth and suppressing dendritic morphology. Consequently, Zn||Zn symmetric cells achieve 1400 h of cycling at −20°C under 1 mA cm ⁻² and 10 mAh cm ⁻² , with a Coulombic efficiency of 99.78% over 1200 cycles. Zn||NVO full cells retain 74% of their initial capacity after 1600 cycles at −20°C, while pouch cells demonstrate stable operation at both room and subzero temperatures. This work establishes a molecular‐to‐interfacial triple‐coupling strategy for temperature‐resilient AZIBs.

The electrochemical reduction of carbon dioxide (CO2) to multi-carbon (C2+) products is a vital pathway for decarbonization. While copper (Cu) is uniquely capable of catalyzing the formation of C2+ products, controlling the crucial C-C coupling step remains challenging. This step is governed by two critical surface factors, local *CO coverage and *CO binding strength, which are typically addressed through physical confinement of *CO intermediates and electronic modulation of the active sites, respectively. Herein, a series of CuO catalysts are synthesized via cellulose-template-induced thermal coalescence, successfully integrating both factors in a single structural motif. This dual-featured architecture provides a confined geometry with an abundance of under-coordinated Cu active sites localized at the particle interfaces. As a results, the increased *CO coverage and enhanced *CO polarization at under-coordinated sites enable the C-C coupling step to proceed via direct *CO dimerization alongside the asymmetric pathway, which are evidenced by combined experimental and theoretical studies. The optimized catalyst achieves a Faradaic efficiency of 70.6% for C2+ products and an industrially relevant partial current density of 211 mA cm-2. This work not only introduces a facile route for preparing dual-feature catalysts but also offers valuable insights into catalyst design for CO2RR and beyond.

Single‐atom catalysts (SACs) enable high metal utilization and offer well‐defined catalytic sites, yet their rational design is hampered by the instability of isolated atoms and an incomplete understanding of how structure governs performance. Early studies focused mainly on the first coordination sphere; however, catalytic behavior is also shaped by second‐sphere interactions, support environments, extended spatial architectures, and their dynamic evolution. In this Review, we establish a cross‐scale framework for the rational design of SACs across interconnected design dimensions: from in‐plane to out‐of‐plane coordination; from primary coordination to through‐bond secondary‐sphere interactions, through‐space microenvironments and metal–support interfaces; and from individual sites to macroscopic architectures governed by site density, intersite distance and topology. We further highlight directed dynamic reconstruction as an active design strategy that links as‐synthesized structures with catalytically relevant working states. By integrating static structure, working‐state evolution, and device operation, this Review provides insights into environment‐dependent performance and guides the rational design of SACs across scales.

Layered oxide cathodes have attracted worldwide attention due to environmentally friendliness, structural diversity, and economic benefits. However, poor long-term cycling and unsatisfactory rate performance hinder the practical application. Hence, an oxide cathode with self-adaptive volume has been designed, achieving stable capacity retention of 82% after 1000 cycles at 2 C. The enhanced long-term performance is attributed to its dynamically adjustable volume reducing the acceleration of stress, enabled by a tunable interlayer distance that expands at the beginning of the charging process and then compresses at the highest voltage. Uniform electric field distribution is depicted by 4-dimensional scanning transmission electron microscopy showing even Coulombic interactions between the oxide layers leading to high mechanical integrity. Such self-adaptable behavior originates from the reduced repulsive force between interlayered oxygen due to the charge reconfiguration of intralayer oxygen and transition metal ions. Additionally, the charge compensation behavior is detected by in situ X-ray absorption spectra, which would be beneficial to high-rate performance. The self-adaptive volume change driven by charge reconfiguration provides a pathway toward durable materials for sustainable sodium-ion energy storage.

Solar‐driven depolymerization of poly(lactic acid) (PLA) into its lactic acid monomer offers an attractive route to plastic recycling coupled with green hydrogen (H ₂ ) production. However, simultaneously achieving high activity and product selectivity remains difficult because of inefficient charge utilization and uncontrolled oxidation pathways. Here, we fabricated cadmium sulfide (CdS) nanorods decorated with atomically dispersed Ni─S ₄ sites that drive selective photocatalytic PLA depolymerization coupled with efficient H ₂ evolution without any sacrificial reagent. The Ni─S ₄ coordination reconstructs the surface electronic structure of CdS, generating interfacial polarization and directing charge separation with markedly prolonged lifetimes for surface redox reactions. Specifically, this redistribution directs photogenerated electrons to proton reduction and localizes holes at the Ni─S ₄ sites, which selectively activate the ester carbonyl for hydroxide‐assisted cleavage while suppressing deeper oxidation. As a result, NiSAs/CdS delivers a H ₂ production rate of 41.74 mmol g ⁻¹ h ⁻¹ while selectively converting PLA into lactic acid, with no detectable accumulation of common over‐oxidation byproducts such as pyruvate or acetate. These findings establish a charge‐coupled pathway that couples selective plastic depolymerization with solar‐driven H ₂ generation and point to a viable strategy for sustainable plastic upcycling.

Understanding the local electronic and atomic structure of materials is central to modern physics, chemistry, materials science, and nanotechnology. X-ray absorption spectroscopy (XAS) provides element-specific insight into these local environments through core-level X-ray absorption processes, making it an irreplaceable technique for studying complex and heterogeneous materials, particularly at the nanoscale. Despite its broad applicability, XAS measurements and data interpretation often remain technically complex and strongly dependent on synchrotron facilities, underscoring the need for clear, accessible, and standardized guidance, particularly for new and occasional users. In this work, we present a set of foundational yet practical protocols for performing XAS measurements and interpretation, covering experimental principles, beamline setup, sample preparation, energy and mode selection, as well as data processing and analysis. We also introduce common tools, methods, and typical practices alongside training modules. These protocols aim to facilitate researchers across disciplines to perform XAS measurements, navigate existing resources, and interpret results for their specific research objectives with greater accuracy, efficiency, and reproducibility.

Developing cost-effective and durable oxygen evolution reaction (OER) catalysts is pivotal for advancing proton exchange membrane water electrolyzers toward large-scale hydrogen production. Cobalt manganese spinel oxides (i.e., Co2MnO4) have emerged as promising nonprecious alternatives owing to their tunable composition and intrinsic OER activity. However, their deployment in acidic media is severely constrained by Mn dissolution and sluggish reaction kinetics governed by adsorbate evolution mechanism (AEM). Herein, we demonstrate that introducing Ir into Co2MnO4 spinels serves a dual function of stabilizing the lattice and enabling a controlled shift toward oxide pathway mechanism (OPM) alongside AEM without lattice oxygen involvement. Density functional theory and spectroscopic analyses reveal that Ir preferentially substitutes Co at octahedral sites, increasing the Mn4+ population and enhancing Mn–O covalency, while facilitating *O–O formation via the OPM pathway. The optimized Ir-Co2MnO4 achieves an overpotential of 222 mV at 10 mA cm–2 and delivers high durability over 416 h at 100 mA cm–2 in 0.5 M H2SO4, including 1000 h of sustained industrial-level operation, surpassing both pristine Co2MnO4 and commercial IrO2. This work provides fundamental insights into Ir-mediated modulation of active sites and establishes a design strategy for high-performance, low-Ir OER catalysts in acidic water electrolysis.

Understanding elemental cooperation in high/medium‐entropy electrocatalysts is essential for rational design but remains challenging due to their compositional complexity. Herein, an amorphous medium‐entropy catalyst, FeCoNiMo‐a, with a nanoring architecture, is developed as a highly active and durable oxygen evolution catalyst. Operando spectroscopic investigations uncover a clear division of elemental functions within the disordered framework. Cobalt is identified as the dominant active centre, forming high‐valence oxyhydroxide species during operation, while iron and molybdenum synergistically regulate the electronic structure and stabilize these oxidized intermediates. In contrast, nickel remains largely metallic, ensuring efficient charge transport and structural robustness. Through these cooperative effects, FeCoNiMo‐a achieves only 190 mV overpotential at 10 mA cm ⁻² in 1 m KOH. When integrated into an anion exchange membrane (AEM) water electrolyser, FeCoNiMo‐a delivers current densities of 1 and 5 A cm ⁻² at 1.6 and 1.9 V, respectively, and operates stably for over 600 h at 1 A cm ⁻² . Further theoretical investigations confirm that Mo incorporation optimizes *OH adsorption and deprotonation, while the amorphous configuration enhances orbital hybridization, facilitating O─O bond cleavage and lattice oxygen participation. This study reveals element‐specific cooperation in medium‐entropy catalysts, guiding the design of non‐precious OER catalysts for practical alkaline water electrolysis.