Pub Date : 2025-03-08DOI: 10.1021/acscatal.5c00014
Sun Seo Jeon, Hyeseong Jeon, Jaewon Lee, Robert Haaring, Wonjae Lee, Jeonghyun Nam, Sung June Cho, Hyunjoo Lee
Minimizing the use of iridium (Ir) in proton exchange membrane water electrolyzers (PEMWEs) is essential for hydrogen production without carbon emission. Herein, layered monoclinic iridium nickel oxide (IrNiOx) platelets were synthesized using the molten salt method and used for the oxygen evolution reaction (OER) in a PEMWE. The IrNiOx hexagonal platelets consist of the edge-sharing octahedral framework, in which Ni atoms replace Ir sites in the crystalline lattice. Thin IrNiOx platelets exhibited high OER activity with suppressed Ni dissolution from the bulk lattice in acidic media. When the platelets were applied in a membrane electrode assembly (MEA), they presented improved interconnectivity in the catalyst layer, facilitating electron transfer. Even at a low Ir loading of 0.2 mgIr cm–2, the platelets presented good performance with an initial cell voltage of 1.70 V at a current density of 1 A cm–2. Despite the use of a Ti porous transport layer (PTL) without Pt coating, the PEMWE operated stably for 150 h, exceeding the performance achievable by commercial Ir oxide and rutile IrO2. When a Pt-coated Ti PTL was used, the PEMWE could be operated stably for 500 h. Incorporating earth-abundant transition metals into the Ir oxide lattice can be an effective way to minimize the use of Ir in PEMWEs.
{"title":"Highly Active and Durable Iridium Nickel Oxide Platelets for a Proton Exchange Membrane Water Electrolyzer with Low Iridium Loading","authors":"Sun Seo Jeon, Hyeseong Jeon, Jaewon Lee, Robert Haaring, Wonjae Lee, Jeonghyun Nam, Sung June Cho, Hyunjoo Lee","doi":"10.1021/acscatal.5c00014","DOIUrl":"https://doi.org/10.1021/acscatal.5c00014","url":null,"abstract":"Minimizing the use of iridium (Ir) in proton exchange membrane water electrolyzers (PEMWEs) is essential for hydrogen production without carbon emission. Herein, layered monoclinic iridium nickel oxide (IrNiO<sub><i>x</i></sub>) platelets were synthesized using the molten salt method and used for the oxygen evolution reaction (OER) in a PEMWE. The IrNiO<sub><i>x</i></sub> hexagonal platelets consist of the edge-sharing octahedral framework, in which Ni atoms replace Ir sites in the crystalline lattice. Thin IrNiO<sub><i>x</i></sub> platelets exhibited high OER activity with suppressed Ni dissolution from the bulk lattice in acidic media. When the platelets were applied in a membrane electrode assembly (MEA), they presented improved interconnectivity in the catalyst layer, facilitating electron transfer. Even at a low Ir loading of 0.2 mg<sub>Ir</sub> cm<sup>–2</sup>, the platelets presented good performance with an initial cell voltage of 1.70 V at a current density of 1 A cm<sup>–2</sup>. Despite the use of a Ti porous transport layer (PTL) without Pt coating, the PEMWE operated stably for 150 h, exceeding the performance achievable by commercial Ir oxide and rutile IrO<sub>2</sub>. When a Pt-coated Ti PTL was used, the PEMWE could be operated stably for 500 h. Incorporating earth-abundant transition metals into the Ir oxide lattice can be an effective way to minimize the use of Ir in PEMWEs.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576258","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}
α-Sulfanyl carbonyl moieties are common structural features in bioactive molecules. Herein, a copper(I)-catalyzed enantioselective alkylation of α-sulfanyl acetamides is disclosed, affording a broad array of chiral α,α-disubstituted amides in high yields with high enantioselectivity. Benzyl bromides, allyl bromides, propargyl bromide, and non-activated alkyl iodides serve as suitable alkylation electrophiles. Furthermore, structurally diversified amides are well tolerated. Control experiments and NMR studies indicate that α-phenylthioacetamide coordinates to the copper(I) catalyst through chelation, leading to activation of the α-protons, facile deprotonation, and subsequent formation of stabilized copper(I)-enolate. Finally, various transformations based on the amide moiety, especially the Weinreb amide, demonstrate synthetic utilities of the present method, together with the formal synthesis of a presynaptic cholinergic modulator (11).
{"title":"Copper(I)-Catalyzed Asymmetric Alkylation of α-Sulfanyl Acetamides","authors":"Hong-Ming Zhang, Zong-Ci Liu, Jun-Zhao Xiao, Liang Yin","doi":"10.1021/acscatal.5c00651","DOIUrl":"https://doi.org/10.1021/acscatal.5c00651","url":null,"abstract":"α-Sulfanyl carbonyl moieties are common structural features in bioactive molecules. Herein, a copper(I)-catalyzed enantioselective alkylation of α-sulfanyl acetamides is disclosed, affording a broad array of chiral α,α-disubstituted amides in high yields with high enantioselectivity. Benzyl bromides, allyl bromides, propargyl bromide, and non-activated alkyl iodides serve as suitable alkylation electrophiles. Furthermore, structurally diversified amides are well tolerated. Control experiments and NMR studies indicate that α-phenylthioacetamide coordinates to the copper(I) catalyst through chelation, leading to activation of the α-protons, facile deprotonation, and subsequent formation of stabilized copper(I)-enolate. Finally, various transformations based on the amide moiety, especially the Weinreb amide, demonstrate synthetic utilities of the present method, together with the formal synthesis of a presynaptic cholinergic modulator (<b>11</b>).","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"68 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575498","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}
Pub Date : 2025-03-07DOI: 10.1021/acscatal.4c07186
Dominique E. Blackmun, Michael R. Gatazka, Pin-En L. Chiu, Marc R. Becker, Corinna S. Schindler
Azetidines and azetines, four-membered nitrogen-containing heterocycles, exhibit unique properties such as low lipophilicity and rigidity, making them promising scaffolds in pharmaceutical design and as synthetic building blocks. However, challenges in their synthesis, particularly azetines, have limited accessibility, hindering the exploration of their applications. Our innovative approach described herein involves a ruthenium-catalyzed oxidative elimination, utilizing a hydroxylamine substituent on the azetidine nitrogen. This method offers milder conditions, enabling the synthesis of 1-azetines from 22 azetidines in yields up to 99%.
{"title":"Ruthenium-Catalyzed Formation of 1-Azetines via Oxidative β-Elimination from Azetidine Benzoates","authors":"Dominique E. Blackmun, Michael R. Gatazka, Pin-En L. Chiu, Marc R. Becker, Corinna S. Schindler","doi":"10.1021/acscatal.4c07186","DOIUrl":"https://doi.org/10.1021/acscatal.4c07186","url":null,"abstract":"Azetidines and azetines, four-membered nitrogen-containing heterocycles, exhibit unique properties such as low lipophilicity and rigidity, making them promising scaffolds in pharmaceutical design and as synthetic building blocks. However, challenges in their synthesis, particularly azetines, have limited accessibility, hindering the exploration of their applications. Our innovative approach described herein involves a ruthenium-catalyzed oxidative elimination, utilizing a hydroxylamine substituent on the azetidine nitrogen. This method offers milder conditions, enabling the synthesis of 1-azetines from 22 azetidines in yields up to 99%.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"91 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575500","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}
The rational design and construction of metal–organic framework (MOF)-based photocatalytic composites with outstanding visible-light responsiveness, rapid photogenerated charge carrier separation and migration ability, and suitable band gaps for photocatalytic organic transformation have gained enormous attention, yet they are highly challenging. Herein, a series of hybrid materials, CdS-x/UiO-66-IPy(Co) (x represents the theoretical loading amount of CdS into the synthetic system), featuring CdS nanoparticles and molecular cobalt centers, have been constructed by a step-by-step assembly (SSA) strategy. Significantly, the resultant CdS-x/UiO-66-IPy(Co) composites present dramatically improved catalytic activity in the oxidative coupling of amines under ambient air and visible-light irradiation (λ > 400 nm) as compared with the parent UiO-66 and CdS. Specifically, CdS-20/UiO-66-IPy(Co) can efficiently convert benzylamine derivatives into the target imine products with conversion and selectivity both exceeding 95%, attributed to the formation of a heterostructure between the well-dispersed CdS nanoparticles, molecular Co catalyst, and UiO-66-NH2, which facilitated an extended range of light absorption, efficient separation and migration of photogenerated charge carriers, and abundant exposed reaction active sites. The recycling experiments confirm the good recyclability and durability of CdS-20/UiO-66-IPy(Co). Furthermore, the underlying catalytic mechanism has been well established by comprehensive experiments involving photocurrent, electrochemical impedance, photoluminescence, transient absorption, and electron paramagnetic resonance spectroscopy measurements.
{"title":"Integration of CdS Nanoparticles and Molecular Cobalt Catalysts into Metal–Organic Frameworks for Highly Efficient Photocatalytic Amine Oxidation","authors":"Lianfen Chen, Zijian Liu, Derui Kong, Qing Tang, Li-Lin Tan, Zhi-Min Liang, Yifan Chen, Cheng-Xia Chen, Shengqian Ma","doi":"10.1021/acscatal.4c07398","DOIUrl":"https://doi.org/10.1021/acscatal.4c07398","url":null,"abstract":"The rational design and construction of metal–organic framework (MOF)-based photocatalytic composites with outstanding visible-light responsiveness, rapid photogenerated charge carrier separation and migration ability, and suitable band gaps for photocatalytic organic transformation have gained enormous attention, yet they are highly challenging. Herein, a series of hybrid materials, CdS-<i>x</i>/UiO-66-IPy(Co) (<i>x</i> represents the theoretical loading amount of CdS into the synthetic system), featuring CdS nanoparticles and molecular cobalt centers, have been constructed by a step-by-step assembly (SSA) strategy. Significantly, the resultant CdS-<i>x</i>/UiO-66-IPy(Co) composites present dramatically improved catalytic activity in the oxidative coupling of amines under ambient air and visible-light irradiation (λ > 400 nm) as compared with the parent UiO-66 and CdS. Specifically, CdS-20/UiO-66-IPy(Co) can efficiently convert benzylamine derivatives into the target imine products with conversion and selectivity both exceeding 95%, attributed to the formation of a heterostructure between the well-dispersed CdS nanoparticles, molecular Co catalyst, and UiO-66-NH<sub>2</sub>, which facilitated an extended range of light absorption, efficient separation and migration of photogenerated charge carriers, and abundant exposed reaction active sites. The recycling experiments confirm the good recyclability and durability of CdS-20/UiO-66-IPy(Co). Furthermore, the underlying catalytic mechanism has been well established by comprehensive experiments involving photocurrent, electrochemical impedance, photoluminescence, transient absorption, and electron paramagnetic resonance spectroscopy measurements.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"30 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569863","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}
Pub Date : 2025-03-07DOI: 10.1021/acscatal.4c07524
Ze-Hui Li, Han Zhang, Ming-Yi Yang, Shuai-Bing Zhang, Mi Zhang, Yu-Fei Liu, Shun-Li Li, Meng Lu, Ya-Qian Lan
Electrocatalytic acetylene reduction (EAR) provides a promising pathway to achieve acetylene (C2H2) semihydrogenation to produce ethylene (C2H4). However, it remains a great challenge to make the electrocatalysts fulfill key factors including C2H2 enrichment, activation, electron transfer, and active sites simultaneously for efficient EAR. Covalent organic frameworks (COFs) have attracted much attention due to the advantages of the introduction of functional groups and efficient electron transfer by covalent linkage, which will be a promising electrocatalyst for EAR, while no studies have achieved EAR by using COFs. In this work, we rationally designed a series of multifunctional COF electrocatalysts encompassing the above functions and achieved efficient EAR by regulating the type of active sites. Among them, the EA-16FCuPc COF exhibits an ∼100% Faraday efficiency of C2H2-to-C2H4 in pure C2H2 flow. Significantly, for industrial crude C2H4 flow containing 1 × 104 ppm of C2H2, EA-16FCuPc COF could produce polymer-grade C2H4 containing only 2.1 ppm of C2H2 impurity and continuously produce pure C2H4 streams (C2H2 < 10 ppm) at large space velocity. This work explored the design of COFs to integrate multiple functions onto one catalyst and achieve efficient EAR, demonstrating the great potential of multifunctional COFs in the field of electrocatalysis.
{"title":"Multifunctional Engineering and Active Sites Regulation of Covalent Organic Frameworks for Efficient Electrocatalytic Acetylene Hydrogenation to Ethylene","authors":"Ze-Hui Li, Han Zhang, Ming-Yi Yang, Shuai-Bing Zhang, Mi Zhang, Yu-Fei Liu, Shun-Li Li, Meng Lu, Ya-Qian Lan","doi":"10.1021/acscatal.4c07524","DOIUrl":"https://doi.org/10.1021/acscatal.4c07524","url":null,"abstract":"Electrocatalytic acetylene reduction (EAR) provides a promising pathway to achieve acetylene (C<sub>2</sub>H<sub>2</sub>) semihydrogenation to produce ethylene (C<sub>2</sub>H<sub>4</sub>). However, it remains a great challenge to make the electrocatalysts fulfill key factors including C<sub>2</sub>H<sub>2</sub> enrichment, activation, electron transfer, and active sites simultaneously for efficient EAR. Covalent organic frameworks (COFs) have attracted much attention due to the advantages of the introduction of functional groups and efficient electron transfer by covalent linkage, which will be a promising electrocatalyst for EAR, while no studies have achieved EAR by using COFs. In this work, we rationally designed a series of multifunctional COF electrocatalysts encompassing the above functions and achieved efficient EAR by regulating the type of active sites. Among them, the <b>EA-16FCuPc COF</b> exhibits an ∼100% Faraday efficiency of C<sub>2</sub>H<sub>2</sub>-to-C<sub>2</sub>H<sub>4</sub> in pure C<sub>2</sub>H<sub>2</sub> flow. Significantly, for industrial crude C<sub>2</sub>H<sub>4</sub> flow containing 1 × 10<sup>4</sup> ppm of C<sub>2</sub>H<sub>2</sub>, <b>EA-16FCuPc COF</b> could produce polymer-grade C<sub>2</sub>H<sub>4</sub> containing only 2.1 ppm of C<sub>2</sub>H<sub>2</sub> impurity and continuously produce pure C<sub>2</sub>H<sub>4</sub> streams (C<sub>2</sub>H<sub>2</sub> < 10 ppm) at large space velocity. This work explored the design of COFs to integrate multiple functions onto one catalyst and achieve efficient EAR, demonstrating the great potential of multifunctional COFs in the field of electrocatalysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"21 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569864","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}
Pub Date : 2025-03-07DOI: 10.1021/acscatal.5c00065
Hanlin Yang, Lingfei Hu, Gang Lu, Xingwei Li, Songjie Yu
Three-dimensional C(sp3)-rich bicyclic scaffolds are vital saturated bioisosteres and versatile building blocks in medicinal and synthetic chemistry. Notwithstanding the importance and progress, the synthesis of bicyclo[4.1.1] and bicyclo[4.2.1] scaffolds remains challenging. Herein, we unveil a rare nickel-catalyzed strain-storage cyclobutanone-alkyne coupling to prepare various functionalized bicyclo[4.1.1]octanes. Moreover, downstream strain-release transformation of bicyclo[4.1.1] scaffolds via rhodium-catalyzed enantioselective sequential C–C activation and 1,4-rhodium shift was efficiently achieved to fuse a variety of enantioenriched bicyclo[4.2.1] scaffolds with high chemo-, diastereo-, and enantioselectivity. Mechanistic studies revealed the well-tailored spironickelabicyclic intermediate with a rigid endo-cyclic olefin favors the strain-storage cyclometalation over the common strain-release-driven β-carbon elimination.
{"title":"Bicyclo[4.1.1]octanes via Strain-Storage Cyclobutanone-Alkyne Coupling and Its Enantioselective Strain-Release Transformation to Bicyclo[4.2.1]nonanes","authors":"Hanlin Yang, Lingfei Hu, Gang Lu, Xingwei Li, Songjie Yu","doi":"10.1021/acscatal.5c00065","DOIUrl":"https://doi.org/10.1021/acscatal.5c00065","url":null,"abstract":"Three-dimensional C(sp<sup>3</sup>)-rich bicyclic scaffolds are vital saturated bioisosteres and versatile building blocks in medicinal and synthetic chemistry. Notwithstanding the importance and progress, the synthesis of bicyclo[4.1.1] and bicyclo[4.2.1] scaffolds remains challenging. Herein, we unveil a rare nickel-catalyzed strain-storage cyclobutanone-alkyne coupling to prepare various functionalized bicyclo[4.1.1]octanes. Moreover, downstream strain-release transformation of bicyclo[4.1.1] scaffolds via rhodium-catalyzed enantioselective sequential C–C activation and 1,4-rhodium shift was efficiently achieved to fuse a variety of enantioenriched bicyclo[4.2.1] scaffolds with high chemo-, diastereo-, and enantioselectivity. Mechanistic studies revealed the well-tailored spironickelabicyclic intermediate with a rigid endo-cyclic olefin favors the strain-storage cyclometalation over the common strain-release-driven β-carbon elimination.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"2 7 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569866","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}
Known for its tunable catalytic properties, high-entropy oxide (HEO) is a promising candidate to achieve stable catalytic performance in thermochemical reforming processes. However, the catalytic mechanism of the polymetallic components has not yet been revealed. This work reports the catalytic mechanism of HEO in H2-rich syngas production from glycerol steam reforming (GSR). A La2CaNiCoMn HEO was rationally designed based on the different functions of the metal components. It was interesting that self-reconstruction was discovered for HEO during the initial stage of the GSR, which was the key to efficient H2 production. NiCo nanoalloy emerged to form a supported-like NiCo/HEO structure with the induction of oxygen lattice consumption, leading to the increasing H2 production rate as the HEO reconstruction proceeded. Segregation energies and M-O bond energies were calculated to further understand the metal exsolution mechanism. The synergistic catalytic effect of the polymetallic components on HEO was analyzed in various aspects by multiscale characterization combined with DFT simulation calculation. The high-temperature-stable catalytic performance was due to the coke precursor formation being inhibited and the strong interaction between NiCo and the parent HEO.
{"title":"Self-Reconstruction Mechanism of High-Entropy Oxide in Glycerol Steam Reforming: The Key to H2-rich Syngas Production","authors":"Mingzheng Liao, Chao Wang, Ying Chen, Yanyu Chen, Chunrun Qin, Yingwei Li","doi":"10.1021/acscatal.4c05270","DOIUrl":"https://doi.org/10.1021/acscatal.4c05270","url":null,"abstract":"Known for its tunable catalytic properties, high-entropy oxide (HEO) is a promising candidate to achieve stable catalytic performance in thermochemical reforming processes. However, the catalytic mechanism of the polymetallic components has not yet been revealed. This work reports the catalytic mechanism of HEO in H<sub>2</sub>-rich syngas production from glycerol steam reforming (GSR). A La<sub>2</sub>CaNiCoMn HEO was rationally designed based on the different functions of the metal components. It was interesting that self-reconstruction was discovered for HEO during the initial stage of the GSR, which was the key to efficient H<sub>2</sub> production. NiCo nanoalloy emerged to form a supported-like NiCo/HEO structure with the induction of oxygen lattice consumption, leading to the increasing H<sub>2</sub> production rate as the HEO reconstruction proceeded. Segregation energies and M-O bond energies were calculated to further understand the metal exsolution mechanism. The synergistic catalytic effect of the polymetallic components on HEO was analyzed in various aspects by multiscale characterization combined with DFT simulation calculation. The high-temperature-stable catalytic performance was due to the coke precursor formation being inhibited and the strong interaction between NiCo and the parent HEO.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"86 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570282","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}
The direct conversion of methane to high-value liquid oxygenates under mild conditions holds considerable appeal. However, a significant dilemma is that target oxygenates are highly susceptible to overoxidation due to the uncontrollable chain dehydrogenation process. This study reveals that various MCrO4 (M = Bi, Pb, Ag2, Ba, Cu) compounds exhibit 100% selectivity for methane oxidation to oxygenates, with Bi8(CrO4)O11 showing the highest activity, producing 556.21 μmol g–1 and an apparent quantum efficiency of 1.54% at 350 nm. The [CrO4] moiety functions as dehydrogenation terminators in the photocatalytic reaction, capturing methane oxidation intermediates and preventing overoxidation. In situ DRIFTS, XPS, and calculations show methane is activated to form oxidation intermediates at the [BiOx] center, which then move to [CrO4]. [CrO4] exhibits an exceptionally high energy barrier (3.40 eV) for deep dehydrogenation, thereby halting the dehydrogenation of oxygenates. This work broadens the design and development of catalysts for inhibiting excessive oxidation of target products.
{"title":"[CrO4] Clusters as Dehydrogenation Terminators for Photocatalytic Oxidation of Methane to Achieve Nearly 100% Oxygenates Selectivity","authors":"Zhengfeng Shen, Jianxin Liu, Lijun Guo, Yawen Wang, Yunfang Wang, Xiao Zhang, Xuan Jian, Xiaoming Gao, Zhongde Wang, Caimei Fan, Rui Li, Jiancheng Wang","doi":"10.1021/acscatal.4c06790","DOIUrl":"https://doi.org/10.1021/acscatal.4c06790","url":null,"abstract":"The direct conversion of methane to high-value liquid oxygenates under mild conditions holds considerable appeal. However, a significant dilemma is that target oxygenates are highly susceptible to overoxidation due to the uncontrollable chain dehydrogenation process. This study reveals that various MCrO<sub>4</sub> (M = Bi, Pb, Ag<sub>2</sub>, Ba, Cu) compounds exhibit 100% selectivity for methane oxidation to oxygenates, with Bi<sub>8</sub>(CrO<sub>4</sub>)O<sub>11</sub> showing the highest activity, producing 556.21 μmol g<sup>–1</sup> and an apparent quantum efficiency of 1.54% at 350 nm. The [CrO<sub>4</sub>] moiety functions as dehydrogenation terminators in the photocatalytic reaction, capturing methane oxidation intermediates and preventing overoxidation. In situ DRIFTS, XPS, and calculations show methane is activated to form oxidation intermediates at the [BiO<sub><i>x</i></sub>] center, which then move to [CrO<sub>4</sub>]. [CrO<sub>4</sub>] exhibits an exceptionally high energy barrier (3.40 eV) for deep dehydrogenation, thereby halting the dehydrogenation of oxygenates. This work broadens the design and development of catalysts for inhibiting excessive oxidation of target products.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"53 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570283","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}
Pub Date : 2025-03-07DOI: 10.1021/acscatal.4c06489
Yihan Liu, Yongpeng Yao, Kiran Siddique, Linquan Bai, Gang Liu, Ting Shi
Indole prenyltransferases (IPTs) play vital roles in the biosynthesis of abundant natural products with diverse biological activities. However, the underlying mechanisms of specific members are not fully understood. Herein, we investigated the detailed reaction mechanism of FgaPT2, a C4 IPT involved in the biosynthesis of important pharmaceutical ergot alkaloids, by employing multiscale calculations and experimental validation. Our study indicates that the C4-prenylation process in FgaPT2 is an unconventional associative reaction accompanied by a short-lived carbocation intermediate rather than a dissociative reaction. The tyrosine shield in FgaPT2 facilitates the prenylation step mainly through hydrogen bond interactions with the dimethylallyl diphosphate. The conserved E89 residue significantly lowers the energy barrier of the prenylation step through the electrostatic interaction. We also confirmed the Cope rearrangement process in the K174A mutant, which results in a reverse-prenylated C3 tricyclic product. By analyzing the MD trajectories, we propose a C6-prenylation mechanism and a prenyl shift reaction from C6 to C5, and finally to the C4 site, which was identified by QM calculation and QCT-MD simulation. Based on our newly proposed mechanism, the C5-prenylated product 5-dimethylallyltryptophan was successfully obtained in the T102N mutant through rational engineering. Our study expands the current understanding of the catalytic mechanism of IPTs and provides insights into the rational modification of IPTs to synthesize a wide variety of high-value prenylated indole products.
{"title":"Understanding and Engineering of C4 Indole Prenyltransferase FgaPT2 by Theoretical Study and Mutation Experiments","authors":"Yihan Liu, Yongpeng Yao, Kiran Siddique, Linquan Bai, Gang Liu, Ting Shi","doi":"10.1021/acscatal.4c06489","DOIUrl":"https://doi.org/10.1021/acscatal.4c06489","url":null,"abstract":"Indole prenyltransferases (IPTs) play vital roles in the biosynthesis of abundant natural products with diverse biological activities. However, the underlying mechanisms of specific members are not fully understood. Herein, we investigated the detailed reaction mechanism of FgaPT2, a C4 IPT involved in the biosynthesis of important pharmaceutical ergot alkaloids, by employing multiscale calculations and experimental validation. Our study indicates that the C4-prenylation process in FgaPT2 is an unconventional associative reaction accompanied by a short-lived carbocation intermediate rather than a dissociative reaction. The tyrosine shield in FgaPT2 facilitates the prenylation step mainly through hydrogen bond interactions with the dimethylallyl diphosphate. The conserved E89 residue significantly lowers the energy barrier of the prenylation step through the electrostatic interaction. We also confirmed the Cope rearrangement process in the K174A mutant, which results in a reverse-prenylated C3 tricyclic product. By analyzing the MD trajectories, we propose a C6-prenylation mechanism and a prenyl shift reaction from C6 to C5, and finally to the C4 site, which was identified by QM calculation and QCT-MD simulation. Based on our newly proposed mechanism, the C5-prenylated product 5-dimethylallyltryptophan was successfully obtained in the T102N mutant through rational engineering. Our study expands the current understanding of the catalytic mechanism of IPTs and provides insights into the rational modification of IPTs to synthesize a wide variety of high-value prenylated indole products.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"23 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575499","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}
Pub Date : 2025-03-07DOI: 10.1021/acscatal.5c01249
Jun Zhu, Shuoqing Zhang, Yongtao Wang, Jia Yao, Xin Hong, Haoran Li
The carbonyl ligands that stabilize the Mn(I) center in the Mn(CO)5Br metal precursor are usually retained upon complexation with the tridentate ligand; however, their presence limits the hydrogenation performance of the Mn complex. Herein, we report the highly selective semihydrogenation of urea derivatives or carbamates, two of the most challenging carbonyl compounds, and polyurethanes to more active formamides using a catalyst system containing earth-abundant metal Mn under mild reaction conditions, which has been previously achieved using precious metal Ru or Ir catalysts. This catalytic activity stems from the fact that the Mn complex bears a noninnocent ligand, which facilitates the simultaneous transfer of both hydrogen atoms from a dihydrogen molecule, thereby avoiding the energetically demanding dihydrogen coordination step observed in systems with exclusively innocent ligands. Additionally, DFT calculations provide insights into the reason for the selective hydrogenation of urea or carbamates to more reactive formamides.
{"title":"Noninnocent Spectator Ligands Facilitate CO Ligand-Stabilized Mn(I) Metal-Catalyzed Hydrogenation of Urea Derivatives or Carbamates to the More Reactive Formamides","authors":"Jun Zhu, Shuoqing Zhang, Yongtao Wang, Jia Yao, Xin Hong, Haoran Li","doi":"10.1021/acscatal.5c01249","DOIUrl":"https://doi.org/10.1021/acscatal.5c01249","url":null,"abstract":"The carbonyl ligands that stabilize the Mn(I) center in the Mn(CO)<sub>5</sub>Br metal precursor are usually retained upon complexation with the tridentate ligand; however, their presence limits the hydrogenation performance of the Mn complex. Herein, we report the highly selective semihydrogenation of urea derivatives or carbamates, two of the most challenging carbonyl compounds, and polyurethanes to more active formamides using a catalyst system containing earth-abundant metal Mn under mild reaction conditions, which has been previously achieved using precious metal Ru or Ir catalysts. This catalytic activity stems from the fact that the Mn complex bears a noninnocent ligand, which facilitates the simultaneous transfer of both hydrogen atoms from a dihydrogen molecule, thereby avoiding the energetically demanding dihydrogen coordination step observed in systems with exclusively innocent ligands. Additionally, DFT calculations provide insights into the reason for the selective hydrogenation of urea or carbamates to more reactive formamides.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"53 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143569868","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：