ChemCatChem最新文献_第7页

Enantioselective Construction of Planar‐Chiral Molecules by Catalytic Asymmetric Late‐Stage Functionalizations 通过催化不对称后期官能化对平面手性分子进行对映选择性构建

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-03 DOI: 10.1002/cctc.202401312

Yu-Hang Zhao, Deng Zhu, Zhi-Min Chen

引用次数: 0

Enhanced Catalytic Stability of Laccase Immobilized on Copper Oxide Nanoparticles 增强固定在纳米氧化铜颗粒上的漆酶的催化稳定性

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401232

F. Javier Suarez, Sergio Ojeda Santillán, Rafael Vazquez-Duhalt, Olivia A. Graeve

{"title":"Enhanced Catalytic Stability of Laccase Immobilized on Copper Oxide Nanoparticles","authors":"F. Javier Suarez, Sergio Ojeda Santillán, Rafael Vazquez-Duhalt, Olivia A. Graeve","doi":"10.1002/cctc.202401232","DOIUrl":"https://doi.org/10.1002/cctc.202401232","url":null,"abstract":"We describe the design and catalytic activity of enzymatic nanoreactors based on copper oxide nanoparticles surface‐functionalized with laccase (CuO‐Lac) from Coriolopsis gallica. Transmission electron micrographs show complete laccase coverage on the nanoparticle surfaces. In addition, the catalytic rate (kcat) of the immobilized laccase is two‐fold higher at an optimized pH, when compared with free laccase, while the affinity constant (KM) is not significantly affected. Importantly, the total turnover number (TNN) of the CuO‐Lac nanoreactors reaches 358 ± 9 × 106 mol ABTS/mol laccase, which is four times higher than the TTN obtained for the free enzyme (88 ± 3 × 106). Thus, our nanoreactors exhibit a significant improvement in laccase catalytic performance. Inductively coupled plasma mass spectrometry was used to confirm the loss of copper ions from free laccase during the catalytic cycle, suggesting that the CuO nanoparticles act as a copper ion source that prevents enzyme inactivation. This work contributes to an improved understanding of the CuO‐laccase interface and confirms that CuO nanoparticles serve as copper sources for laccase during catalysis.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"38 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

TEMPO‐Catalyzed Continuous‐flow Aerobic Oxidations of Alcohols on Silica 二氧化硅上 TEMPO 催化的酒精连续流有氧氧化反应

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401152

Kai Takizawa, Takuma Ishihara, Shinki Tani, Yusuke Hamada, Koichiro Masuda, Shun-ya Onozawa, Kazuhiko Sato, Shū Kobayashi

{"title":"TEMPO‐Catalyzed Continuous‐flow Aerobic Oxidations of Alcohols on Silica","authors":"Kai Takizawa, Takuma Ishihara, Shinki Tani, Yusuke Hamada, Koichiro Masuda, Shun-ya Onozawa, Kazuhiko Sato, Shū Kobayashi","doi":"10.1002/cctc.202401152","DOIUrl":"https://doi.org/10.1002/cctc.202401152","url":null,"abstract":"2,2,6,6'‐Tetramethylpiperidine‐N‐oxyl (TEMPO) is a highly efficient oxidation catalyst, valued for its environmentally benign nature, particularly in comparison to transition‐metal catalysts. Despite their merits, TEMPO‐based catalysts are not notably cost‐effective. Immobilization of TEMPO onto supports offers a promising strategy to overcome this limitation. In this work, we present the synthesis and application of immobilized TEMPO catalysts 2–5, prepared via a straightforward condensation reaction, for the aerobic oxidation of alcohols. These catalysts demonstrate remarkable activity for alcohol oxidations under continuous‐flow conditions, employing nitric acid as the co‐catalyst. Notably, catalyst 2 immobilized by COOH silica gel exhibits outstanding performance for the oxidation of benzyl alcohol by oxygen gas, achieving a turnover frequency (TOF) of 15 h−1 and a turnover number (TON) exceeding 300. Catalyst 2 further demonstrates broad substrate scope, effectively oxidizing primary, secondary, and benzylic alcohols. Post‐reaction analysis of spent catalyst 2 reveals that deactivation primarily stems from nitrosation of the N‐O bond. Interestingly, the amide moiety remains intact despite the harsh acidic reaction conditions.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"7 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Revisiting the Reviewed: A Meta‐Analysis of Computational Studies on Transition Metal‐Catalysed Hydrogenation Reactions 重温回顾：过渡金属催化加氢反应计算研究的元分析

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401053

Michael Bühl, Shahbaz Ahmad

引用次数: 0

Construction of Mesoporous Aluminosilicate Thin Films on ITO Electrodes for Immobilizing a Cationic Ru(II) Water Oxidation Catalyst 在 ITO 电极上构建用于固定阳离子 Ru(II) 水氧化催化剂的介孔硅酸铝薄膜

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401199

Masaya Okamura, Shunpei Harada, Ayano Yamada, Narumi Nakano, Shiro Hikichi

{"title":"Construction of Mesoporous Aluminosilicate Thin Films on ITO Electrodes for Immobilizing a Cationic Ru(II) Water Oxidation Catalyst","authors":"Masaya Okamura, Shunpei Harada, Ayano Yamada, Narumi Nakano, Shiro Hikichi","doi":"10.1002/cctc.202401199","DOIUrl":"https://doi.org/10.1002/cctc.202401199","url":null,"abstract":"Aluminosilicate (Al‐SiO2) thin films with vertically aligned mesochannels were successfully synthesized on ITO electrodes and employed for the immobilization of a cationic Ru(II) water oxidation catalyst without requiring linker groups. Optimal synthesis conditions yielded uniform mesoporous Al‐SiO2 films with tunable Al content, high surface area (568 m2/g), 3.94 nm pore size, and 155 nm thickness. Electrochemical studies confirmed the presence of the immobilized Ru complex undergoing diffusion‐controlled Ru(III/II) and Ru(IV/III) electron transfer. The Ru loading reached 4.71 nmol/cm2 at Si/Al = 9.6, with higher Al content enhancing loading amounts via cation exchange. The Ru‐modified electrode exhibited high electrocatalytic water oxidation activity, achieving 75.3% Faradaic efficiency and a turnover number of 298.6 for O2 evolution for 1 hour. This work provides a new approach to construct porous environments on an electrode surface to immobilize positively charged transition‐metal complexes as catalysts, offering potential applications in the development of electrocatalytic systems for energy conversion.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"469 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Non‐Oxidative Dehydroaromatization of Linear Alkanes on Intermetallic Nanoparticles 线性烷烃在金属间纳米颗粒上的非氧化脱氢芳香化反应

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401263

Ranjan K. Behera, Andrew R. Lamkins, Minda Chen, Raghu V. Maligal-Ganesh, Jiaqi Yu, Wenyu Huang

{"title":"Non‐Oxidative Dehydroaromatization of Linear Alkanes on Intermetallic Nanoparticles","authors":"Ranjan K. Behera, Andrew R. Lamkins, Minda Chen, Raghu V. Maligal-Ganesh, Jiaqi Yu, Wenyu Huang","doi":"10.1002/cctc.202401263","DOIUrl":"https://doi.org/10.1002/cctc.202401263","url":null,"abstract":"There has been significant interest in developing new catalytic systems to convert linear chain alkanes into olefins and aromatics. In the case of higher alkanes (≥ C6), the production of aromatic compounds such as benzene‐toluene‐xylenes is highly desirable. However, as the length of the carbon chain increases, the dehydrogenation process becomes more complex, not only due to the challenges of C‐H activation but also the need for selectivity towards the desired products by the possibility of side reactions such as isomerization and cracking. Here, we present a detailed analysis of the dehydroaromatization of n‐hexane, n‐heptane, and n‐octane, using PtSn intermetallic nanoparticles supported on SBA‐15 as the catalyst. Through in‐situ spectroscopic and kinetic analysis, we have probed into the reaction kinetics, catalyst deactivation, and a mechanistic understanding of the dehydroaromatization process on the surface of the PtSn intermetallic nanoparticles. Introducing Sn has been shown to be crucial not only for enhancement of catalytic activity, but also for higher aromatics selectivity and stability on stream. Furthermore, the analysis of dehydroaromatization reaction rates of reactant and possible intermediates indicates that the dehydroaromatization of n‐hexane to benzene likely proceeds through initial dehydrogenation steps followed by ring closing.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"18 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative Study of Si‐O‐Al and Si‐O‐Si Bond Stability in HZSM‐5 Zeolite Under Steam and Hot Liquid Water Environments 蒸汽和热液态水环境下 HZSM-5 沸石中 Si-O-Al 和 Si-O-Si 键稳定性的比较研究

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401270

Linhai He, Jing Niu, Songyue Han, Dong Fan, Wenna Zhang, Shutao Xu, Yingxu Wei, Zhongmin Liu

{"title":"Comparative Study of Si‐O‐Al and Si‐O‐Si Bond Stability in HZSM‐5 Zeolite Under Steam and Hot Liquid Water Environments","authors":"Linhai He, Jing Niu, Songyue Han, Dong Fan, Wenna Zhang, Shutao Xu, Yingxu Wei, Zhongmin Liu","doi":"10.1002/cctc.202401270","DOIUrl":"https://doi.org/10.1002/cctc.202401270","url":null,"abstract":"Understanding the changes in the zeolite framework and catalytic active sites in zeolite‐based vapor‐phase and aqueous catalytic processes is crucial. Herein, the evolution of framework T atoms (Si and Al) in ammonium hexafluorosilicate (AHFS)‐treated HZSM‐5 zeolite under steam and hot liquid water (HLW) environments was inverstigated using various characterization techniques. In the HLW environment, Si‐O‐Si bonds exhibit poorer hydrothermal stability than Si‐O‐Al bonds, in contrast to the steam environment. Significant Si atom leaching occurs without or with the removal of framework tetrahedral Al atoms (Al(IV)‐1). Similar to steam, Al(IV)‐1 species in the HLW environment sequentially evolve into partially coordinated framework Al species and then into extra‐framework Al (EFAL) species through partial and complete hydrolysis. The generated EFAL species act as Lewis acid sites, but their local structures or chemical environments may differ. These findings reveal the difference in the T‐O‐T bonds attacked by water molecules: the Si‐O‐Al bonds is primarily attacked in steam, whereas the Si‐O‐Si bond is primarily attacked in HLW.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"262 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Atomic‐level synergistic catalysts: single‐atom site integrated with atom, cluster and nanoparticle 原子级协同催化剂：单原子位点与原子、团簇和纳米粒子的整合

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-09-02 DOI: 10.1002/cctc.202401331

Pan Zhu, Wuyi Feng, Jing Liu, Ting Liu, jiatao zhang, di zhao

{"title":"Atomic‐level synergistic catalysts: single‐atom site integrated with atom, cluster and nanoparticle","authors":"Pan Zhu, Wuyi Feng, Jing Liu, Ting Liu, jiatao zhang, di zhao","doi":"10.1002/cctc.202401331","DOIUrl":"https://doi.org/10.1002/cctc.202401331","url":null,"abstract":"The emerging atomic‐level synergistic catalysts based on the single‐atom sites and other valuable components, such as atom, cluster, nanoparticle and other nano‐matter, shine in various catalytic fields. They can integrate the advantages of individual catalytic sites and other valuable components to enhance the activity, selectivity and stability of many chemical reactions via activating their key rate‐determining steps and multistep transformations. In addition, because of the ultrahigh atom utilization (~100%) and adjustable microenvironment of metal centers, the single‐atom sites can intelligently construct with other useful large size sites to strengthening in tandem a typical catalytic process. Herein, the structure and mechanism of atomic‐level synergistic catalysts with controllable electronic structures and regulatory reaction processes are presented. We particularly emphasize the interactions between active components of atomic‐level synergistic catalysts and catalytic reaction processes, which are essential for understanding how these catalysts are cooperatively working. It is anticipated that this minireview can make the promotion of advanced atomic‐level synergistic catalysts based on single‐atom sites.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"58 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regulating the Electronic Structure of Pd Nanoparticles on NH3‐pretreated Nano‐flake TiO2 for Efficient Hydrogenation of Nitrile Butadiene Rubber 调节 NH3 预处理纳米片 TiO2 上钯纳米粒子的电子结构以实现丁腈橡胶的高效氢化

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-08-31 DOI: 10.1002/cctc.202401226

Shidong Wang, Benwei Fan, Bingqing Ge, Hongwei Zhang, Cejun Hu, Qinyan Cui, Xiaojun Bao, Pei Yuan

{"title":"Regulating the Electronic Structure of Pd Nanoparticles on NH3‐pretreated Nano‐flake TiO2 for Efficient Hydrogenation of Nitrile Butadiene Rubber","authors":"Shidong Wang, Benwei Fan, Bingqing Ge, Hongwei Zhang, Cejun Hu, Qinyan Cui, Xiaojun Bao, Pei Yuan","doi":"10.1002/cctc.202401226","DOIUrl":"https://doi.org/10.1002/cctc.202401226","url":null,"abstract":"The heterogeneous selective hydrogenation of nitrile butadiene rubber (NBR) is an efficient method to generate high value‐added hydrogenated NBR. Nevertheless, the inherent large molecular size and high spatial hindrance of polymers lead to poor activity and metal loss. Herein, we report a simple support ammonia pretreatment strategy for the synthesis of efficient N‐doped Pd catalyst and applied for the NBR hydrogenation. The results reveal that N doping enhances electrons transfer from the support to Pd more effectively than oxygen‐rich vacancy carrier, thereby substantially enhancing the electron cloud density and stability of the Pd sites. The formation of more electron‐rich Pd sites not only significantly enhances the adsorption‐activation ability of C=C and H2, but also lowers the apparent activation energy of the reaction. As a result, the Pd/N‐TiO2‐R demonstrates best activity with a hydrogenation degree (HD) of 98% and a TOF value of 335 h‐1, significantly higher than that of Pd/TiO2‐R (HD=83%, 282 h‐1) and Pd/TiO2 (HD=74%, 204 h‐1). This strategy will provide new inspiration to improve the activity and stability of Pd/TiO2 catalysts for the hydrogenation of unsaturated polymers.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"60 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modified H‐BEA Zeolites from Fluorinated Silica Slag Waste by Dry Gel Conversion Method for Shape‐Selective Acylation of 2‐Methoxynaphthalene 利用干凝胶转化法从含氟硅渣废料中提取改性 H-BEA 沸石，用于 2-甲氧基萘的形状选择性酰化反应

IF 4.5 3区化学

ChemCatChem Pub Date : 2024-08-30 DOI: 10.1002/cctc.202401381

Xiao Wang, Zhongkui Zhao

{"title":"Modified H‐BEA Zeolites from Fluorinated Silica Slag Waste by Dry Gel Conversion Method for Shape‐Selective Acylation of 2‐Methoxynaphthalene","authors":"Xiao Wang, Zhongkui Zhao","doi":"10.1002/cctc.202401381","DOIUrl":"https://doi.org/10.1002/cctc.202401381","url":null,"abstract":"The high value‐added utilization of the fluorinated silica slag (FSS) waste, an associated by‐product of the anhydrous HF production from the accompanying fluorine resources in phosphate ore, is of great importance, but it remains a challenge. In this work, the Mg modified and unmodified Hβ zeolites from FSS waste were successfully prepared by a green dry gel conversion crystallization method with tetraethylammonium hydroxide (TEAOH) as a structure‐directing agent (SDA). The in situ Mg modified Hβ zeolite (Mg‐Hβ) shows much superior catalytic performance to unmodified (Hβ) and post Mg‐modified Hβ (Mg/Hβ) zeolites for acetylation of 2‐methoxynaphthalene (2‐MN) to 6‐acetyl‐2‐methoxynaphthalene (2,6‐AcMN), and the 40.2% of conversion for 2‐MN with 66.3% of selectivity for 2,6‐AcMN were achieved, ascribed to the high amount of B acidic sites and the promoted shape‐selective catalysis effect by higher surface area and volume of micropores. This work not only opens a new avenue for the high value‐added utilization of fluorinated silica slag waste, but also generates an efficient solid acid catalyst for the clean production of 2,6‐AcMN through the acetylation of 2‐MN with acetic anhydride.","PeriodicalId":141,"journal":{"name":"ChemCatChem","volume":"25 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0