Asymmetric Fe-N3C coordination in Fe single-atom sites boosts electrochemical activation of H2O2 for efficient •OH generation.

Harnessing NIR-II-responsive Rh single-atom nanozymes for photothermal-catalytic immunomodulation and eradication of drug-resistant biofilms in deep tissues.

In-situ monitoring of atomically dispersed Pt sites supported on OMS-2 during CO2 activation

Atomically precise single-atom catalysts (SACs) are essential for establishing reliable structure-activity relationships, yet synthetic routes that afford SACs with fully resolved coordination microenvironments remain a significant challenge. Here we report a secondary building unit (SBU) deconstruction-reorganization strategy that converts the dicopper Cu2(COO)4 cluster in Cu2(TCA)4/3 (H3TCA = 4,4',4″-tricarboxytriphenylamine) framework into a Y4(μ3-OH)4Cu2(COO)12 heterometallic cluster through the introduction of Y3+ and 2-fluorobenzoic acid modulator. Single-crystal X-ray diffraction unambiguously captures this reorganization, which expands the Cu···Cu distance from 2.6 to 10.3 Å, generates two isolated square CuO4 sites, and preserves the spatial arrangement of all TCA linkers with minimal lattice perturbation. The resulting framework, CCNUF-51, adopts a (3,8)-connected the topology arising from merging two adjacent 4-connected paddlewheel nodes of the parent pto net into a single 8-connected node. CCNUF-51 exhibits good chemical stability (pH 2-12), attributed to the synergistic coordination of hard Y3+ and soft Cu2+ within the heterometallic SBU. The atomically dispersed Cu sites are intimately coupled to photoactive TCA linkers, enabling highly efficient photocatalytic benzylic C(sp3)-H functionalization─including esterification, sulfonamidation, and methoxylation─that outperforms CuI, Cu(OAc)2, Cu2(TCA)4/3, and benchmark Cu/UiO-66 SAC. This work establishes SBU deconstruction-reorganization as an effective route for accessing SACs with atomically well-defined active sites.

Engineering direct electron transfer in single-atom-bridged nanozymes for enhanced oxidase-like activity at neutral pH.

Wide-temperature NOx removal via NH3-SCR enabled by synergistic atomically dispersed Ce-V dual sites: anti-sulfur performance and new insight on the role of NH4HSO4

Self-sacrificial template anchoring strategy for the preparation of highly dispersed metal site catalysts for efficient degradation of tetracycline hydrochloride.

Synergistic effect of hydroxyl and superoxide radicals-driven by highly dispersed FeCo-NC dual active sites in singlet oxygen generation in heterogeneous electro-Fenton systems

The photocatalytic oxidation of the inert C-H bond remains a paramount challenge, plagued by both rapid carrier recombination in kinetics and slow surface reactions in thermodynamics. Herein, we present a conceptually distinct strategy to simultaneously resolve both core challenges by tailoring surface polarons on photocatalysts via anchoring atomically dispersed Mn sites onto a low-crystallinity SnO2 support. These atomic sites induce localized lattice distortions via strong electron-phonon coupling, generating surface small polarons that serve a dual function. Kinetically, these polarons trap photogenerated electrons within picoseconds, suppressing bulk recombination and establishing a dominant, long-lived interfacial charge transfer channel (∼65 ps) directly to the reactants, as revealed by femtosecond transient absorption spectroscopy (fs-TAS). Thermodynamically, the polaronic field strengthens toluene adsorption (adsorption energy strengthened from -0.49 to -0.91 eV) and polarizes the C-H bond, significantly lowering the activation barrier, as confirmed by density functional theory (DFT) calculations and in situ DRIFTS. Consequently, the Mn1/SnO2 catalyst achieved about 100% efficiency in the challenging toluene oxidation with a high weight hourly space velocity (WHSV) of 60,000 mL·gcat-1·h-1 under a continuous flow system. Additionally, the Mn1/SnO2 catalyst exhibited exceptional stability over 600 min and resistance to relative humidity (RH) ranging from 5% to 90%. This work elucidated the fundamental role of surface polarons in harmonizing charge dynamics with surface catalysis, offering a powerful strategy for designing highly efficient and robust photocatalysts for challenging chemical transformations.

Despite the promise of fuel cells as sustainable energy conversion technologies, their widespread adoption is hindered by the high cost of platinum group metal (PGM) catalysts, particularly for catalyzing the oxygen reduction reaction (ORR) at the cathode. Here, we report copper-based single-atom catalysts (Cu-SACs) as cost-effective non-PGM alternatives for ORR. The catalysts were synthesized via simple pyrolysis of pyrene-derived amine-terminated graphene quantum dots (GQDs) in the presence of nitrogen and metal precursors. The abundant nitrogen functionality in GQDs effectively stabilized isolated Cu atoms during their conversion to porous carbon. A subsequent acid-washing step yielded a high density of atomically dispersed Cu active sites. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-resolution scanning transmission electron microscopy (HR-STEM) confirmed the effective incorporation of isolated Cu atoms into the carbon matrix through copper-nitrogen (Cu-N) coordination. Electrochemical measurements revealed excellent ORR activity with a dominant four-electron pathway. This synthetic strategy provides a practical route to developing economically viable, non-precious metal catalysts.

Atomically dispersed Fe-N-C catalysts with well-defined iron-nitrogen coordination exhibit fantastic promise for the oxygen reduction reaction (ORR). However, achieving their scalable synthesis while preventing iron aggregation and performance degradation remains a critical challenge. Here, we demonstrate a highly efficient confined flash Joule heating (CFJH) technique for the scalable and ultrafast synthesis of Fe-N-C catalysts. The coal-derived porous carbons are efficient in confining iron phthalocyanine (FePc) molecules, suppressing their migration and iron aggregation during ultrafast CFJH treatment. This process facilitates the conversion of FePc into atomically dispersed FeN4 sites embedded within a graphitization-enhanced carbon framework. Mechanistic studies reveal that, compared to an FePc precursor, these integrated FeN4 sites exhibit a shifted rate-determining step with optimized adsorption/desorption of oxygen intermediates, leading to a reduced energy barrier for efficient 4e- oxygen reduction. The resulting catalyst exhibits impressive ORR activity in alkaline media with a high half-wave potential (0.90 V vs RHE) and remarkable durability (94.5% retention over 100 h). The assembled zinc-air battery delivers a peak power density of 277.6 mW cm-2 and sustains stable operation for over 900 h, outperforming the Pt/C + IrO2 benchmark. Scalable production is achieved at a rate of 0.5 kg h-1, establishing a facile and industrially viable route for synthesizing high-performance atomically dispersed catalysts.

Mesoporous zeolite-anchored atomically dispersed metal (ADM) catalysts are capable of overcoming diffusion limitations, promoting mass transfer, and exposing more active sites. These features make them one of the most ideal heterogeneous catalysts. However, introducing both mesoporosity and ADM species into zeolite structures while avoiding metal clustering remains a significant challenge. Herein, we report the hierarchical MFI zeolite encapsulated atomically dispersed nickel species using a ligand-protected in situ synthesis strategy with a tri-functional template. This template incorporates quaternary ammonium hydrophilic head groups linked to central metal-coordinated porphyrins by alkyl chains, which guide the formation of mesoporous MFI zeolite structure while simultaneously suppressing nickel clustering. The resulting catalyst exhibits a hierarchical architecture comprising MFI nanosheets with enhanced 90° rotational intergrowth, and the dispersed Ni sites are evenly distributed within the zeolite framework. The catalyst exhibited a high activity and efficient utilization of Ni in probing CO2 hydrogenation reaction. The use of functionalized metal-coordinated porphyrins as a structure-directing agent to generate zeolite-supported metal catalysts is transferable, which opens new possibilities for controlling zeolite architecture.

Cobalt phthalocyanine encapsulation boosts oxidase-like activity of single-atom CoNC nanozyme for fluorescence sensing of tetracycline.

Sluggish sulfur reaction kinetics present a critical barrier to the practical application of sulfide-electrolyte (SE) based all-solid-state lithium-sulfur batteries (ASSLSBs). Achieving high performance requires both lowering the intrinsic energy barrier for sulfur conversion and engineering efficient transport pathways. Herein, we address these challenges by designing atomically dispersed cobalt sites on carbon nanotubes to directionally catalyze sulfur conversion at the triple phase interface. Strong orbital hybridization between Co 3d and S 3p states strengthens chemical bonding, effectively accelerating both sulfur reduction and lithium sulfide oxidation. The interfaces tailored for directional catalysis maximize highly ordered C/S/SE triple-phase interfaces and minimize SE/C interfaces, establishing hierarchical ionic/electronic transport networks while mitigating side reactions. Consequently, the engineered cathode delivers a high reversible capacity of 1108 mAh g- 1 at 0.5 C, retaining 97 % capacity over 500 cycles. The resulting batteries also demonstrate remarkable robustness under demanding conditions. This work offers a powerful catalysis-driven strategy for high-performance ASSLSBs.

Water flow-driven electrocatalytic system coupling redox processes for the deep mineralization of halogenated organic compounds.

Achieving long-term durability of oxygen reduction reaction (ORR) catalysts is a critical requirement for the practical deployment of electrochemical energy technologies, such as fuel cells and metal-air batteries. Platinum-based (Pt-based) catalysts remain the benchmark for ORR activity. However, their high cost, limited availability, and performance degradation caused by carbon corrosion, nanoparticle agglomeration, and Pt dissolution present significant barriers for sustained performance. In parallel, iron-nitrogen-carbon (Fe-N-C) catalysts have emerged as promising alternatives, delivering near-Pt activity through atomically dispersed Fe-Nx active sites. Yet, their insufficient stability, primarily due to Fe leaching and protonation-induced deactivation, continues to hinder their practical applications. This review comprehensively summarizes recent advances in improving the stability and durability of Pt-based and Fe-N-C catalysts. For Pt-based systems, strategies include electronic structure regulation, entropy-driven alloying, and support-interface engineering. For Fe-N-C catalysts, progress has been made in graphitization enhancement, heteroatom doping, defect engineering, and dual-metal site incorporation, all aiming to suppress degradation pathways. Furthermore, structure-stability correlations revealed by experimental and computational studies provide mechanistic insights into degradation processes and stability-limiting factors. Special attention is given to the interactions among catalyst structure, electronic configuration, and electrochemical microenvironment, offering guidance for robust catalyst design. Finally, we discuss ongoing challenges and future opportunities for developing highly stable ORR catalysts, providing a roadmap toward next-generation cost-effective and durable ORR catalysts, and accelerating the industrial realization of sustainable energy conversion technologies.

Redox-engineered gold single-atom nanozymes orchestrate mitochondria-driven PANoptosis for energy-independent cancer catalytic therapy.

Polyurethane-based heterogeneous catalysts with highly dispersed Rh single sites for reductive hydroformylation of olefins

Hollow-structured Fe-N-C catalysts with atomically dispersed Cu sites for enhanced oxygen reduction activity and stability

The widespread occurrence of pharmaceutical contaminants in aquatic environments poses significant risks to ecosystems and public health, necessitating the development of efficient and sustainable treatment technologies. Herein, a visible-light (VL)–active zinc single-atom catalyst supported on biochar (SAZn@BC) was synthesized via pyrolysis and applied for the degradation of ibuprofen (IBP), sulfamethoxazole (SMX), trimethoprim (TMP), and carbamazepine (CBZ) in water. Structural characterization confirmed the presence of g-C3N4 domains, abundant oxygen-containing functional groups, and atomically dispersed Zn sites with a Zn–N4 coordination environment. Under VL irradiation, SAZn@BC achieved degradation efficiencies of 43.9%, 64.4%, and 61.9% for IBP, SMX, and TMP, respectively, within 30 min, while CBZ exhibited limited removal. Mechanistic investigations combining quenching experiments, electrochemical analyses, and X-ray photoelectron spectroscopy revealed that superoxide and hydroperoxyl radicals were the dominant reactive oxygen species, with hydroxyl radicals and singlet oxygen contributing to a lesser extent. In addition, a nonradical pathway involving direct interfacial electron transfer between oxygen functional groups on the biochar support and pharmaceutical molecules played a critical role, mediated by single-atom Zn sites and enhanced under VL irradiation. These findings demonstrate that SAZn@BC enables synergistic radical and nonradical pathways for pharmaceutical degradation and represents a promising strategy for water treatment applications.