118 Search Results

Lithium and manganese-rich (LMR) layered oxides represent a leading class of high-energy cathode materials, but their practical realization is fundamentally limited by severe manganese (Mn) dissolution, a process that triggers structural degradation and rapid capacity fade. While mitigation efforts have predominantly focused on interfacial engineering, the intrinsic contribution of bulk electrolyte solvation to this degradation pathway remains largely unexplored, primarily due to the difficulty of deconvolving its effects from concurrent cathode-electrolyte interphase (CEI) formation. Here, we report an experimental design to isolate the role of solvation. We systematically varied the electrolyte solvent solvation power by substituting the strongly coordinating ethylenemore » carbonate (EC) with its weaker coordinating fluorinated derivatives, fluoroethylene carbonate (FEC) and trans-4,5-Difluoro-1,3-dioxolan-2-one (DFEC), while maintaining a consistent interfacial chemistry. Remarkably, the electrolyte formulated with the weakest solvent, DFEC, exhibits superior cycling stability, suppressing Mn dissolution by up to 63% relative to the conventional EC-based system. Post-mortem analysis unequivocally attributes this performance enhancement to the preservation of the LMR cathode's structural integrity, a direct consequence of mitigated Mn dissolution. This work provides conclusive evidence that modulating bulk electrolyte solvation is a potent and direct strategy for stabilizing LMR cathodes, establishing a vital design principle for next-generation battery systems.« less

Single-site heterogeneous catalysts offer an attractive route to unite the molecular precision of homogeneous catalysis with the durability and practical advantages of solids. Surface organometallic chemistry (SOMC) provides a particularly powerful strategy for this purpose by grafting molecular precursors onto tailored surfaces and converting support functionalities into ligand environments for isolated metal centers. As a result, SOMC brings the language and logic of coordination chemistry to heterogeneous catalysis, where the support becomes an integral part of the active site coordination sphere. This Review surveys recent progress in the rational design of SOMC-derived single-site catalysts, with emphasis on synthetic routes, postmore » synthetic transformations, and the deliberate tuning of catalytic behavior through metal-support interactions. Discussions are made on how support identity, hydroxyl topology, acidity, and redox activity shape the geometry, electronic structure, and oxidation state of supported metal sites, as well as how these factors determine activity, selectivity, and stability. We also examine a central limitation of these systems: despite their molecularly informed design, supported single sites often exist as structurally distributed ensembles rather than uniform species, particularly on amorphous supports. This site heterogeneity, along with catalyst dynamics under operating conditions, remains a major barrier to definitive structure-activity relationships. Therefore, emerging approaches that combine advanced characterization, first-principles modeling, ensemble kinetics, and machine learning to resolve active-site structure and guide catalyst development are highlighted. Together, these advances position SOMC as a versatile coordination chemistry framework for the predictive design of heterogeneous catalysts with well-defined molecularly tailored active sites.« less

Magic-size metal chalcogenide clusters of molecular size exhibit well-defined structure and unique properties that might be further expanded with the incorporation or substitution of a second metal. We report the postmodification of magic-size clusters synthesized in polymer thin films via exposure to volatile metal organic precursors commonly utilized for atomic layer deposition. Exposure of In6S6(CH3)6 clusters to dimethylcadmium results in exposure-dependent incorporation of Cd2+, which extends the optical absorbance of the clusters into the visible spectrum. The mechanism for Cd2+ incorporation is consistent with Cd2+ replacement of In3+ that includes methyl ligand removal to maintain charge neutrality. Even for clustersmore » embedded in a polymer matrix, ligand loss leads to sintering and transformation into larger nanoscale aggregates with zinc blende-type structure. The extent of Cd incorporation can be modulated by varying the process temperature and volatile metal organic exposure as well as the choice of volatile metal organic precursor. A computational thermodynamic analysis of heteroatom incorporation for several metals and chemistries reveals that both the stability of the substituted cluster and the favorability of reaction byproducts jointly determine the favorability of cation incorporation.« less

Artificial intelligence (AI) is increasingly integrated into catalysis science, enabling agentic workflows in which AI systems perceive inputs, reason under constraints, plan, and autonomously execute in silico or physical experiments with minimal human intervention. While these closed-loop capabilities hold promise for accelerating catalysis research, they introduce new sources of variability that can undermine rigor and reproducibility (R&R). These risks are particularly pronounced in heterogeneous catalysis, where subtleties in catalyst synthesis, activation, and testing can strongly influence catalytic outcomes. To address these challenges, we introduce TRACE-AI (transparent reporting for agentic catalysis enabled by artificial intelligence) as a set of community guidelinesmore » with a publication checklist. TRACE-AI emphasizes end-to-end traceability of catalysis campaigns, linking scientific queries to data and models, reasoning and actions, and the knowledge acquired. Here, by promoting standardized reporting, TRACE-AI aims to cultivate a foundation for accelerating scientific discovery while reinforcing R&R as autonomous catalysis laboratories continue to emerge.« less

Few-atom metal chalcogenide clusters may be realized through the sequential infiltration of metal-organic precursors in polymer films. However, the underlying nucleation and growth mechanisms that allow for cluster synthesis with near atomic-scale precision are not fully resolved. The kinetics of the sequential infiltration synthesis (SIS) method that control the nucleation and growth mechanisms of primarily Cd4S4-core clusters within a poly(4-vinylpyridine) (P4VP) matrix are probed with in situ UV-visible absorbance spectroscopy. Density functional theory (DFT) calculations that allow simulation of the optical properties of cluster fragments further reveal the thermodynamics that guide cluster growth within the P4VP matrix. We conclude thatmore » a reactive capture mechanism for cluster nucleation and growth is dominant, although transient dimethyl cadmium adduction to the polymer backbone may contribute to cluster nucleation under shorter metal-organic purge process conditions. Grazing incidence X-ray diffraction (GI-XRD) and X-ray absorption spectroscopy (XAS) analyses further corroborate the cluster size and atom connectivity throughout the stepwise synthesis.« less

Recent studies have demonstrated the relative stability of undercoordinated hexanuclear cobalt sulfide nanoclusters (NCs) with different charge states. Considering that these small metal NCs have atomically precise structures and high reactivity due to the open shell of the transition metals, and provide selectivity toward ligand loss, they are a vital model for catalysis. In this paper, the electronic structures of these NCs are investigated. These NCs are then used as the reference state to analyze the catalytic properties with respect to hydrogen evolution reaction (HER) and CO2 reduction (CO2R). Further, to understand the effect of heteroatom incorporation, the geometry andmore » reactivity of ten different metal dopants are analyzed. This work shows that the type of metal incorporation greatly affects the electronic structure and formation energies for ligand binding and catalysis. Particularly, the d-orbital occupancy in the cobalt atoms remains largely unchanged, while the heteroatom greatly influences the reactivity of the undercoordinated NCs. Most notably, this work highlights that transition metals in [Co5MS8(PEt3)5]1+ NCs would competitively prefer electrochemical adsorption of H over COOH, while the main group metals prefer COOH adsorption.« less

Mesoporous silicon nitride (Si3N4) enables access to chemisorbed group IV organometallics catalysts active for propane dehydrogenation (PDH) compared to the organometallic analogues on mesoporous silica under the same reaction conditions. The series of Si3N4-supported materials are active catalysts, (Zr > Hf > Ti k f = 290, 232, and 162 mol mol(Metal)(-1) h(-1) at 450 degrees C with 2% C3H8 in Ar, respectively) with selectivity above 95%, demonstrating additional examples of Ti and Hf systems for PDH. However, the underlying mechanism of the improved performance relative to oxide supported homologues is not well-understood. Characterization of thermally treated samples (DRIFTS, XASmore » and SSNMR) and computational modeling of this catalyst series was utilized to differentiate between potential amido- (C-H activation along the M-N bond) and imido- (C-H activation along the M=N bond) mechanisms. Due to remaining mechanistic ambiguity, a Ga analogue was synthesized and evaluated for PDH activity as an indirect probe to experimentally differentiate pathways. An inversion of the oxide/nitride performance trend is observed for the Ga congener which does not form a Ga=N bond, most consistent with different mechanisms dictating the performance of the group IV/Si3N4 catalysts vs Ga/Si3N4.« less

We report an electrochemical CO₂ reduction reaction catalyzed by a paramagnetic and conductive CuO/Cu interface with spins polarized by a moderate external magnetic field (MF) of similar to 800 gauss, achieving a similar to 30% increase in CO₂-to-C₂₊ Faradaic efficiency (FE) compared to that in the absence of the MF in a flow cell electrolyzer. At a current density of 400 mA/cm², the CO₂-to-C₂₊ FE reached 86.7 ± 2.7% with 47.9 ± 1.4% cathodic energy efficiency (EE) in contrast to the CO₂-to-C₂₊ FE of 67.6% with 36.4% of EE in the absence of MF. Notably, ethanol production exhibits a muchmore » higher response to the MF (similar to 55.6% increase in FE) than ethylene (similar to 6.4% increase in FE) at 400 mA/cm². In situ surface-enhanced Raman spectroscopy (SERS) captured magnetic-field-enhanced *CO coverage and ethanol-forming C₂ intermediates on CuO/Cu, providing direct spectroscopic evidence of spin-modulated pathway selection. Here, computational study suggests that the enhancement of ethanol selectivity is due to the reduced reaction kinetic barrier under MF, while the ethylene selectivity is less affected, mainly due to the insensitivity of the kinetic barriers under MF.« less

Atomic layer deposition (ALD) is a powerful technique for thin film synthesis, offering atomic-scale precision and conformality. While ALD of MgO has been widely studied for applications in energy storage and microelectronics, its potential as surface on which deposition may be selective and defects repaired remains underexplored. In this work, we present a combined theoretical and experimental investigation of MgO surface hydration and its implications for targeted ALD growth using water and dimethyl aluminum isopropoxide (DMAI) as reactants. We perform density functional theory (DFT) calculations to examine molecular and dissociative H2O adsorption on MgO (100) terraces and step-edge sites, includingmore » pristine surfaces and those with Mg/O vacancies. Reaction Gibbs free energies are calculated under various conditions to quantify surface reactivity. Our findings reveal facet- and defect-dependent hydration behaviors that align with experimental ALD growth trends on MgO (100). This study provides a molecular-level understanding of MgO surface chemistry critical for optimizing ALD processes for thin film growth and defect repair.« less

Enabling higher yield and better selectivity for fine-chemical synthesis through heterogeneous catalysis is intricately linked to the interplay of active sites, reaction conditions, and mass transfer influence provided by the catalyst. Alkyne semihydrogenation is ubiquitous in the production of bulk chemicals in the pharmaceutical, polymer, or fine-chemical industries, but product selectivity remains a major challenge. Here, we demonstrate that the design of catalysts encompassing nickel (Ni) foams as contiguous monolith supports, decorated with ultralow loading of Pd/PdOx nanoparticles on a carbonized polydopamine interface and tuned with a thin layer of Al2O3, in conjunction with an optimized reaction environment leads tomore » highly selective alkyne semihydrogenation. The reactions demonstrate good functional group tolerance and applicability to flow reactor systems. Combined computational and experimental studies are presented to describe the synergistic effect between the solvent-surface interaction and the degree of Pd surface reduction that are necessary to promote this selectivity. The system highlights the opportunity for catalyst-solvent codesign as a benign alternative to more complex reactants featuring extrinsic poisons or less-favored dopants.« less