Journal of the American Chemical Society最新文献

{"title":"Optimizing the Mass Transport and Atomic Fe Intrinsic Activity to Achieve High-Performing Fuel Cells","authors":"Haiyang Fan, Yarong Liu, Jiaxin Li, Zunhang Lv, Changli Wang, Rui Liu, Feilong Dong, Chongao Tian, Xiao Feng, Wenxiu Yang, Bo Wang","doi":"10.1021/jacs.5c03499","DOIUrl":"https://doi.org/10.1021/jacs.5c03499","url":null,"abstract":"Due to the insufficient three-phase interfaces and high oxygen transport resistance, the high intrinsic activity cannot be sufficiently utilized in practical proton-exchange membrane fuel cells (PEMFCs). The efficient transport of protons and reactants within the catalyst layers (CL) is largely influenced by the pore structure of the carbon support, hosting both metal sites and ionomers. Herein, we constructed a porous nanosheet Pt-free catalyst (Fe_AC-N-SC) by selecting a highly nitrogen-rich GT-18 MOF via salt template to realize the improvement of PEMFC performance. The simulation and experimental results illustrate that the microstructure can benefit the homogeneous dispersion of ionomers and facilitate oxygen mass transport in the cathode CL, ultimately achieving efficient utilization of catalytic activities. The PEMFC assembled from the Fe_AC-N-SC catalyst exhibited an outstanding peak power density of 1.1 W cm^–2 and durability (61% power density retention after <i>AST</i>-30k cycles and 92% voltage retention after 100 h OCV test). DFT results demonstrated that the introduction of Fe atomic clusters can boost the intrinsic activity of ORR by regulating the electron distribution of single-atomic Fe–N₄ sites. This study reveals the relationship between CL design, mass transport, and electrode microstructure, which successfully exploits the intrinsic activity of cathode catalysts and enhances the power generation capacity.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"31 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering Spatial Interface in Supported Molecular Complexes for Ampere-Level Electrocatalytic Oxygen Evolution","authors":"Yun Gao, Chengdong Yang, Xiaobo Zheng, Zechao Zhuang, Jiarui Yang, Yuhai Dou, Jintao Zhang, Dingsheng Wang","doi":"10.1021/jacs.5c02247","DOIUrl":"https://doi.org/10.1021/jacs.5c02247","url":null,"abstract":"Homogenized molecular complexes with active single sites hold great promise for electrocatalytic conversion processes. However, the influence of the spatial gap between coordination complexes and the carbon support on electron shuttling remains poorly understood. Herein, we demonstrate a supramolecular architectural strategy that leverages oxygen sites to strengthen the complex-support interactions, thereby elucidating the oxygen evolution reaction (OER) catalytic mechanism effected by the spatial gap. Experimental results reveal that the narrow gap would benefit electron shuttling and stabilize the molecular complexes, enabling the ampere-level current densities. Typically, the optimized biphenyl-4,4′-dicarboxylic acid-coordinated Fe–Ni complexes exhibit superior electrocatalytic performance with a current density of 1.5 A cm^–2 and a mass activity of 41,206 A g_Fe/Ni^–1 at an overpotential of 0.33 V. Theoretical studies further demonstrate that the highly electrophilic oxygen bridging between iron and nickel sites would promote the formation of key intermediates on iron sites (Fe–OOH*). These findings demonstrate the significant roles of complex-support interactions in designing heterogeneous molecular complexes.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"56 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperpolarized 13C NMR by Dissolution DNP Enables Snapshot Detection of Degradation Products in Lithium-Ion Battery Electrolytes","authors":"Chloé Gioiosa, Ekaterina V. Pokochueva, Julien Dieterich, James Tolchard, Charlotte Bocquelet, Mohamed Ayman Ennachet, Nghia Le, Laurent Veyre, Damien Montarnal, Anne Lesage, Ségolène Laage, Simon Pondaven, Sami Jannin","doi":"10.1021/jacs.5c03773","DOIUrl":"https://doi.org/10.1021/jacs.5c03773","url":null,"abstract":"Dissolution Dynamic Nuclear Polarization (dDNP) is a powerful hyperpolarization technique enabling sensitivity gains beyond 4 orders of magnitude in solution nuclear magnetic resonance (NMR). Over the last decades, researchers’ efforts have led to an extension of dDNP applications in numerous research fields. Lithium-ion batteries are one of the most widespread types of rechargeable batteries, which calls for a deeper understanding of the various physicochemical mechanisms involved in making them more efficient, safe, and sustainable. One of the key challenges lies in better understanding the degradation of the battery electrolyte to mitigate it, as it can significantly impact the battery’s performance. While NMR has been used in attempts to understand these mechanisms, notably by investigating the degradation products, the intrinsic lack of sensitivity of this technique, combined with the limited accessible volume of such compounds, makes its application often challenging. In this work, we combine several state-of-the-art dDNP methodologies, including the use of recently introduced hyperpolarizing polymers (HYPOPs), to acquire hyperpolarized ¹³C NMR spectra of battery electrolytes. We show that we can successfully detect ¹³C signals on formulated battery electrolyte solutions in different degradation stages on a 600 MHz spectrometer, with sensitivity gains of up to 3 orders of magnitude. This work paves the way for studying lithium-ion battery electrolyte degradation under real usage conditions (cycling, thermal aging, air exposure, etc.) with a ¹³C detection limit below the micromolar range. This methodology has the potential to provide new insights into degradation mechanisms and the role and effectiveness of additives to mitigate electrolyte degradation.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"46 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144133539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stabilization of Condensate Interfaces Using Dynamic Protein Insertion","authors":"Yannick H. A. Leurs, Sanne N. Giezen, Yudong Li, Willem van den Hout, Jay Beeren, Linn J. M. van den Aker, Ilja K. Voets, Jan C. M. van Hest, Luc Brunsveld","doi":"10.1021/jacs.5c03740","DOIUrl":"https://doi.org/10.1021/jacs.5c03740","url":null,"abstract":"Coacervates have been widely used to mimic membraneless organelles (MLOs). However, coacervates without a membrane or stabilizing surface do not feature the same level of stability as MLOs. This study shows that specifically engineered surface-active proteins can interact with the interface of polypeptide coacervates, conferring resistance to coacervate dissolution and fusion. Modulating the molecular characteristics of these coacervate stabilizing proteins highlighted that their dimerization aids in achieving effective interface stabilizers. Cryo-TEM imaging showed a densely packed protein monolayer at the coacervate-liquid interface, while single-molecule super-resolution microscopy captured the dynamic nature of this protein layer, with the proteins rapidly (un)docking and moving across the coacervate interface within milliseconds. These findings suggest a dynamic form of coacervate stabilization driven by transient protein interactions at the condensate interface. This unique form of coacervate stabilization not only provides a new approach to developing stable and dynamically exchanging synthetic condensate systems but, as model systems, can also significantly contribute to our understanding of the mechanisms underlying the temporal stability of MLOs in nature.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"59 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Ice Splitting into H2 and O2 Enabled by High Ionic Conductivity.","authors":"Bohan Deng,Guangqiang Yu,Wei Zhao,Zhuting Zhang,Xiaoyan Li,Kai Huang,Lifen Wang,Hailin Peng,Huajian Gao,Xibo Li,Hui Wu","doi":"10.1021/jacs.5c01779","DOIUrl":"https://doi.org/10.1021/jacs.5c01779","url":null,"abstract":"The molecular splitting of H2O is fundamentally significant in energy conversion and storage. While liquid water splitting has achieved scientific and engineering success, the decomposition of solid-state ice has yet to be realized. Here we demonstrate that ice can be directly split at temperatures as low as -40 °C. We show that ice can serve as a high-performance solid electrolyte for proton and hydroxide conduction, with proton mobility estimated to be 1-2 orders of magnitude higher than in liquid water. As a result, ice splitting is achieved at a voltage of 2.18 V at 10 mA cm-2, with an energy efficiency of approximately 70% at -10 °C. By using ice as a solid electrolyte, ice splitting circumvents the issue of hydrogen crossover, which is inherent in water splitting. These findings introduce new pathways for energy conversion and storage through ice at sub-0 °C temperatures and further provide new insights for the understanding of the electrochemical process in ice.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"4 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing Dual-Interface Built-In Electric Fields within Janus Heterostructures for Cooperative Photoredox Catalysis.","authors":"Yi-Wen Han,Yu-Xin Zhang,Lei Ye,Tian-Jun Gong,Xue-Bin Lu,Ning Yan,Yao Fu","doi":"10.1021/jacs.5c01171","DOIUrl":"https://doi.org/10.1021/jacs.5c01171","url":null,"abstract":"Rationally designing nanostructures and comprehensively understanding the structure-property relationships are important for directional charge transfer. A general dual-interface built-in electric field (BIEF) regulation strategy is developed to synthesize the bifunctional ZnS/Sv-chalcogenide/Ti3C2 heterostructure photocatalysts (Sv represents sulfur vacancies; chalcogenides include ZnIn2S4, CdS, and CdIn2S4) consisting of a ZnS/chalcogenide S-scheme heterojunction and a Sv-chalcogenide/Ti3C2 Schottky heterojunction. The ternary-component photocatalyst construction involves hollow core-shell heterostructure establishment via lateral epitaxy and chalcogenide-surface Ti3C2 nanoparticle introduction via a defect-mediated heterocomponent anchorage. These nanoreactors integrate the strong intrinsic driving force and enhanced interfacial electronic coupling, leveraging resulting dual-interface BIEFs for precise carrier mobility control and robust redox performance feedback. The BIEF-induced ultrafast charge transfer features powerful photocarrier enrichment and feeble photocarrier recombination at the ZnS/ZnIn2S4 S-scheme heterointerface as well as continuous steering of photocarrier localization and delocalized electron transport at the Sv-ZnIn2S4/Ti3C2 Schottky heterointerface. Simultaneously, BIEF-induced targeted molecule catalysis is marked by complementary adsorption and selective activation of key intermediates. Representative ZnS/Sv-ZnIn2S4/Ti3C2 demonstrates broad substrate compatibility and superhigh reactivity in cooperative biomass valorization and hydrogen evolution. This study provides a programmable framework for manipulating BIEFs by multicomponent ordered-space integration and interface engineering, elucidating the substantial impact of dual-interface BIEFs on carrier transport behavior and molecular catalytic behavior.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"15 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bis-Allylic Deuterated Docosahexaenoic Acid-Esterified Phospholipids Resist In Vivo Peroxidation in Rat Brain","authors":"Secilia Garza, Genevieve James, Hui Gyu Park, Paul R. S. Baker, Martin-Paul Agbaga, Vicki Ea, Mikhail S. Shchepinov, J. Thomas Brenna","doi":"10.1021/jacs.4c17871","DOIUrl":"https://doi.org/10.1021/jacs.4c17871","url":null,"abstract":"The human central nervous system simultaneously has the most highly unsaturated fatty acids (HUFAs) and the highest metabolic rate among body tissue. Up to 1% of consumed O₂ is converted to reactive oxygen species (ROS) that cause unregulated damage to HUFA-rich membrane phospholipids (PLs). Docosahexaenoic acid (DHA) is the brain’s most unsaturated and abundant HUFA. Reinforcing the ROS-labile <i>bis</i>-allylic positions with deuterium (D-DHA) protects against oxidative damage in vitro and in vivo. We developed an LC–MS/MS method to detect ambient levels of nascent oxidation products of DHA and D-DHA containing PLs <i>in vivo</i> in rat brain lipid extracts. Multiple reaction monitoring (MRM)-triggered mass spectra confirmed D-DHA incorporation in D-DHA-fed rat brain PLs. DHA-PL nascent oxidation products add 2 O, consistent with known peroxidation reactions. In contrast, D-DHA oxidation is primarily detected as a single O addition, consistent with epoxidation. D-DHA-PL showed 20%–30% lower overall oxidation compared to DHA-PL. Our data are consistent with a mechanism of action whereby D-DHA blocks excess lipid peroxidation, leading to lower overall membrane damage. D-DHA is a unique therapeutic approach against neurodegenerative diseases where ROS-driven oxidation is implicated.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"14 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guanine Crystallization by Particle Attachment","authors":"Shashanka S. Indri, Florian M. Dietrich, Avital Wagner, Michal Hartstein, Einat Nativ-Roth, Mariela J. Pavan, Leeor Kronik, Matteo Salvalaglio, Benjamin A. Palmer","doi":"10.1021/jacs.5c04543","DOIUrl":"https://doi.org/10.1021/jacs.5c04543","url":null,"abstract":"Understanding how crystals nucleate is a key goal in materials, biomineralization, and chemistry. Many inorganic materials are known to crystallize “nonclassically” by particle attachment. However, a molecular-level understanding of small molecule crystallization is hampered by the complexity and time scales of nucleation events, which are often too large to simulate and too small to observe. Here, by combining unbiased molecular dynamics simulations and <i>in situ</i> experiments, we uncover this nucleation “blind spot” to elucidate the nonclassical crystallization mechanism of the nucleobase, guanine. The multi-step nucleation process begins with stacked guanine clusters, whose H-bonding and π-stacking arrangement progressively orders as they attach into nanoscopic fibers (observed by simulation and electron microscopy), partially ordered bundles, and finally, 3D periodic crystals. This work provides a foundation for understanding how organisms exquisitely control the formation of guanine and other molecular crystals, which are used ubiquitously in biology as optical and nitrogen-storage materials.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"33 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Responsive Organoselenium Dendritic Polymers: From Monodisperse Dendrimers to Self-Assembled Micelles for Advanced Therapeutic Applications.","authors":"Natalia Sanz Del Olmo,Jorge San Jacinto García,Yikai Yin,Ying Zhao,Moustapha Hassan,Michael Malkoch","doi":"10.1021/jacs.5c00811","DOIUrl":"https://doi.org/10.1021/jacs.5c00811","url":null,"abstract":"Selenium (Se) is a highly biologically active element, and its organic derivatives have attracted growing interest for their promising chemotherapeutic potential, largely due to their redox-modulating activity, which selectively affects cancer cells with high levels of reactive oxygen species (ROS). However, their high reactivity and susceptibility to spontaneous degradation limit their biomedical application. To harness their potential in the realm of nanomedicine, we present a new generation of therapeutically promising polymers that combine Se with 2,2-bis(methylol)propionic acid (bis-MPA)-based dendritic polymers, chosen for their high chemical versatility, low toxicity, and excellent biodegradability. Most examples in the literature about dendritic polymers feature dormant dendritic skeletons with active functional groups expressed only on their periphery, which severely limits their functional scope. In this work, monodisperse dendrimers and linear-dendritic (LD) polymers up to the third generation were developed, with the latter capable of self-assembling into dendritic micelles (∼20 nm). These systems feature Se at the dendritic core or peripheral branches in the form of monoselenide or diselenide bridges. Selenium incorporation demonstrated excellent compatibility with two key polyester synthetic approaches: anhydride chemistry and fluoride-promoted esterification (FPE). Both monoselenide and diselenide linkages introduced degradability and dynamic behavior in dendrimers and dendritic micelles. However, their biological activities differed significantly. Diselenide-containing dendrimers exhibited great anticancer potential against breast cancer cell lines, with IC50 values in the micromolar range. Among these, first-generation Se dendrimers stood out due to their promising selectivity toward cancer cells. In contrast, dendritic polymers incorporating monoselenides retained the high biocompatibility characteristics of bis-MPA dendritic constructs.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"130 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Basis for Medium-Chain Dehydrogenase/Reductase-Catalyzed Reductive Cyclization in Polycyclic Tetramate Macrolactam Biosynthesis.","authors":"Xiangqian Xie,Fan Li,Yanxin Mu,Mengyao Lu,Jie Luo,Haoxin Wang,Yuemao Shen,Liangcheng Du,Deyu Zhu,Yaoyao Li","doi":"10.1021/jacs.5c04971","DOIUrl":"https://doi.org/10.1021/jacs.5c04971","url":null,"abstract":"Few enzymes are known to catalyze reductive cyclizations via nucleophile-mediated C-C bond formation. Medium-chain dehydrogenases/reductases (MDRs) typically function as dehydrogenases or reductases. However, a distinct subclass of MDRs involved in polycyclic tetramate macrolactam (PoTeM) biosynthesis catalyzes reductive cyclizations via hydride-mediated C-C bond formation. Here, we present the apo and substrate-bound structures of OX4 and CftD, two enzymes responsible for the third ring formation in PoTeMs biosynthesis. Structural and mutational analysis reveal a catalytic mechanism wherein OX4 initiates a NADPH-dependent 1,6-reduction, followed by cyclization to form the C11-C22 bond, water-mediated protonation of the C7-carbonyl oxygen, and a final tautomerization to produce the cyclized product. Precise substrate positioning and stabilization of the enolate intermediate by the conserved residue W260 are critical for catalysis. These findings represent the first structural and mechanistic understanding of this newly identified cyclase subgroup and offer promising new avenues for enzyme engineering and natural product biosynthesis.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"13 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}