Journal of Catalysis最新文献_第7页

Elucidating the correlation between active species and branch distribution of polyethylene in Ziegler-Natta catalysis 阐明Ziegler-Natta催化反应中活性物质与聚乙烯分支分布的关系

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-25 DOI: 10.1016/j.jcat.2025.116092

Tao Guo , Chuanding Dong , Xiaokai Cheng , Jingdai Wang , Yongrong Yang , Wei Li

{"title":"Elucidating the correlation between active species and branch distribution of polyethylene in Ziegler-Natta catalysis","authors":"Tao Guo , Chuanding Dong , Xiaokai Cheng , Jingdai Wang , Yongrong Yang , Wei Li","doi":"10.1016/j.jcat.2025.116092","DOIUrl":"10.1016/j.jcat.2025.116092","url":null,"abstract":"<div><div>The ethylene/α-olefin copolymers synthesized by Ziegler-Natta catalysts generally exhibit much higher Short-Chain Branch (SCB) concentration in the low-molecular-weight fraction, which hampers the mechanical properties of the final products. Herein, we investigate the mechanism underlying the origin of SCB distribution at a molecular level. We design a spherical catalyst combining two alcohols with different mobility, after which a second titanation step with incremental TiCl4 loading is applied to drive the migration of alcohol molecules. This migration induces not only the escape of alcohols from the catalyst surface but also the coordination of alcohols with Ti centers, which regulates the mobility of active species on the catalyst surface. We demonstrate that the aggregation behavior of Ti species is directed by their bonding to the MgCl2 surface, where either TiCl3-like clusters or isolated Ti3+ sites can be preferentially synthesized during triethylaluminium activation. Further polymerization results combined with electron paramagnetic resonance analysis show that TiCl3-like clusters and the “dormant” active species contribute to the uniform SCB distribution over different molecular weights, whereas the predominated isolated Ti3+ sites on the MgCl2 (110) plane concentrate the SCB in the low-molecular-weight fraction of the synthesized polyethylene. Taken together, we reveal a correlation between polymer branching distribution and catalytic structures, and show that the latter can be regulated by tailoring the migration of alcohols.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"446 ","pages":"Article 116092"},"PeriodicalIF":6.5,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695887","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}

引用次数: 0

Self-Promoting NO electrochemical reduction via N-N coupling by Surface-Adsorbed *NH intermediates on Mo2C nanosheets Mo2C纳米片表面吸附*NH中间体通过N-N耦合自促进NO电化学还原

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-24 DOI: 10.1016/j.jcat.2025.116097

Xiang Huang , Xiangting Hu , Jiong Wang , Hu Xu

{"title":"Self-Promoting NO electrochemical reduction via N-N coupling by Surface-Adsorbed *NH intermediates on Mo2C nanosheets","authors":"Xiang Huang , Xiangting Hu , Jiong Wang , Hu Xu","doi":"10.1016/j.jcat.2025.116097","DOIUrl":"10.1016/j.jcat.2025.116097","url":null,"abstract":"<div><div>Electrochemical reduction of NO (NORR) to ammonia has gained significant attention due to its potential in both electrocatalytic denitrification and ammonia synthesis. Transition-metal carbides (TMCs), with their high reactivity toward NO activation, have emerged as promising candidates for NORR electrocatalysts. However, their exceptional catalytic performance in the hydrogen evolution reaction (HER)—a major competing process—may hinder the Faradaic efficiency of NH3 production. Interestingly, recent experimental studies have shown that NORR almost completely suppresses HER on Mo2C nanosheets under typical HER operating conditions, but the underlying mechanism remains unclear. Here, using state-of-the-art grand canonical density functional theory calculations, we reveal the atomic-level reaction mechanism of NORR on TMCs by taking experimentally reported Mo2C as a prototype. Our findings show that within the potential range of −0.3 V to 0 V vs. RHE, the Mo2C surface becomes nitrogenated by a monolayer of chemisorbed *NH intermediates, leading to poisoning of the surface. However, these adsorbed surface *NH intermediates can effectively adsorb NO molecules through an N-N coupling mechanism, facilitating their electrochemical reduction to NH3 with fast reaction kinetics and favorable thermodynamics, thereby showing a self-promoting catalytic mechanism. Importantly, these *NH intermediates significantly suppress HER through strong electrostatic repulsion with incoming protons (or adjacent *NH species), leading to barriers exceeding 2 eV for both Heyrovsky and Tafel reactions. Our calculations provide crucial insights into the decisive role of *NH intermediates in promoting NH3 production while suppressing H2 generation, thus providing valuable guidance for the rational design of TMC-based NORR electrocatalysts.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"446 ","pages":"Article 116097"},"PeriodicalIF":6.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695889","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}

引用次数: 0

Quantifying π-electron delocalization as a universal descriptor for ORR activity in MN4 catalysts 量化π-电子离域作为MN4催化剂中ORR活性的通用描述符

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-24 DOI: 10.1016/j.jcat.2025.116093

Miao-Ying Chen , Jiabo Le , Hao-Ran Wu , Wei-Dong Li , Jia-Nan Zhang , Bang-An Lu

{"title":"Quantifying π-electron delocalization as a universal descriptor for ORR activity in MN4 catalysts","authors":"Miao-Ying Chen , Jiabo Le , Hao-Ran Wu , Wei-Dong Li , Jia-Nan Zhang , Bang-An Lu","doi":"10.1016/j.jcat.2025.116093","DOIUrl":"10.1016/j.jcat.2025.116093","url":null,"abstract":"<div><div>The development of high-performance transition metal and nitrogen co-doped carbon (M−N−C) catalysts for the oxygen reduction reaction (ORR) hinges on identifying robust and quantitative descriptors for catalytic activity. In this study, we introduce the π-electron delocalization factor (Δπ) in the carbon basal plane as a universal and quantitative descriptor for ORR activity. By combining experimental data and density functional theory (DFT) calculations, we demonstrate that Δπ systematically tunes the d-orbital energy levels of MN4 active sites, particularly the dz2 orbital, which governs the adsorption of oxygen intermediates and influences the rate-determining step of the ORR. A linear correlation between Δπ and ORR kinetics across different metal centers (Fe, Mn, Co, Ni) highlights the pivotal role of π-electron delocalization in optimizing the metal–oxygen interaction. This study provides a novel framework for quantifying catalytic performance and offers an efficient strategy for the rational design and screening of next-generation M−N−C catalysts with enhanced ORR activity.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116093"},"PeriodicalIF":6.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678088","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}

引用次数: 0

Theoretical insights and predictions: Photocatalytic functionalization of C(sp3)−H bonds in methane using [W10O32]4− [W10O32]4-催化甲烷中C(sp3)- h键的光催化功能化

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-24 DOI: 10.1016/j.jcat.2025.116101

Yu-Jiao Dong , Bo Zhu , Zhong-Min Su , Wei Guan

{"title":"Theoretical insights and predictions: Photocatalytic functionalization of C(sp3)−H bonds in methane using [W10O32]4−","authors":"Yu-Jiao Dong , Bo Zhu , Zhong-Min Su , Wei Guan","doi":"10.1016/j.jcat.2025.116101","DOIUrl":"10.1016/j.jcat.2025.116101","url":null,"abstract":"<div><div>Methane activation catalyzed by [MW9O32]n− (n = 3–5) and [MW5O19]m− (m = 1–3) was investigated through Density Functional Theory (DFT) calculations. We identified the key active species, active site, and reaction mechanism by studying the model reaction of methane hydroalkylation catalyzed by [W10O32]4−. Systematic comparisons across modified polyoxometalates (POMs) revealed multiple electronic and structural descriptors governing methane activation efficiency. A key discovery involves the role of photoinduced surface-bridging oxygen holes in [W10O32]4−, which serve as active sites for cleaving the inert C(sp3)<img>H σ-bond. While other POMs, including [W6O19]2−, [PW12O40]3−, and [P2W18O62]6−, also exhibit methane-activating oxygen holes, their requirement for higher-energy UV excitation (compared to the visible-light-responsive [W10O32]4−) likely explains the latter’s broader utility in organic synthesis. Electronic structure analysis uncovered a near-linear correlation between triplet POM β-LUMO energies and C(sp3)<img>H activation barriers. Crucially, the negative charge density of POMs inversely regulates β-LUMO energetics: lower anionic charges correspond to reduced β-LUMO energy levels and consequently lower activation barriers. This structure–activity relationship implies that strategic charge modulation in POM architectures can fine-tune frontier molecular orbital levels, thereby controlling catalytic performance in methane functionalization. Based on these principles, we propose the low-charge metal-substituted POM [ReW5O19]− as a promising candidate for X<img>H bond activation (X = S, C, N, O).</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116101"},"PeriodicalIF":6.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678090","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}

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Halogen-free and solvent-free CO2 cycloaddition via adjusting the types of surface defect and doped metal on the metal-doped M/AlOOH catalysts 通过调整金属掺杂M/AlOOH催化剂表面缺陷和掺杂金属的类型，实现无卤素和无溶剂CO2环加成

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-24 DOI: 10.1016/j.jcat.2025.116099

Lixuan Ma , Na Li , Baojun Wang , Maohong Fan , Lixia Ling , Riguang Zhang

{"title":"Halogen-free and solvent-free CO2 cycloaddition via adjusting the types of surface defect and doped metal on the metal-doped M/AlOOH catalysts","authors":"Lixuan Ma , Na Li , Baojun Wang , Maohong Fan , Lixia Ling , Riguang Zhang","doi":"10.1016/j.jcat.2025.116099","DOIUrl":"10.1016/j.jcat.2025.116099","url":null,"abstract":"<div><div>The development halogen-free, solvent-free heterogeneous catalysts for CO2 cycloaddition with epoxides remains critical, as conventional homogeneous systems face challenges in product separation and leave halogen residues. This work addresses these limitations by designing a series of halogen-free M/AlOOH catalysts with different types of doped metal M and surface defects, to optimize CO2 cycloaddition with ethylene oxide (EO) by the regulation of acid-base properties. Theoretical and experimental analyses reveal that Lewis acid-base pairs composed of M∙∙∙VH and M∙∙∙VOH could stabilize the ring-opening intermediates (LO/LC) and promote EO ring-opening over M/AlOOH catalysts. Crucially, activated CO2δ− species mimic halogen’s nucleophilic role in attacking EO, with catalytic activity exhibiting an inverted volcano relationship to the Bader charge of CO2δ− species, Optimal performance occurs when the CO2δ− charge within 0.23 ∼ 0.55 e, where enhanced nucleophilicity drives cycloaddition. This study establishes a rational strategy for designing sustainable heterogeneous catalysts that eliminate halogens and solvents while maintaining high activity, offering a blueprint for green catalytic systems in CO2 utilization.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116099"},"PeriodicalIF":6.5,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695888","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}

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An urgent call for robust statistical methods in reliable feature importance analysis across machine learning 迫切需要在机器学习中可靠的特征重要性分析中使用稳健的统计方法

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-24 DOI: 10.1016/j.jcat.2025.116098

Yoshiyasu Takefuji

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Tuning the regioselectivity of heterogeneous hydroformylation by engineering carbon species microenvironment around Rh sites 通过在Rh位点周围设计碳种微环境来调节非均相氢甲酰化的区域选择性

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-23 DOI: 10.1016/j.jcat.2025.116095

Li Huang , Jia Wang , Qi Liu , Peng Sun , Mengnan Nie , Guang Gao , Zelun Zhao , Zhiwei Huang , Fuwei Li

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Corrigendum to “Effectiveness factor for catalyst pellets of non-basic shapes” [J. Catal. 445 (2025) 116052] “非基本形状催化剂球团的有效系数”的勘误表[J]。Catal. 445 (2025) 116052]

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-22 DOI: 10.1016/j.jcat.2025.116082

Hong Yong Sohn , Bahador Abolpour

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The role of the Pt-group dehydrogenation catalyst in alkane metathesis for polyolefin deconstruction pt基团脱氢催化剂在烷烃分解分解聚烯烃中的作用

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-20 DOI: 10.1016/j.jcat.2025.116070

Selena Moore , Andrew Tran , Andreas Palmateer , Jose Naranjo Mendez , Dimitri Gatzios , Peter Eschbach , Joel Miscall , Lucas D. Ellis

{"title":"The role of the Pt-group dehydrogenation catalyst in alkane metathesis for polyolefin deconstruction","authors":"Selena Moore , Andrew Tran , Andreas Palmateer , Jose Naranjo Mendez , Dimitri Gatzios , Peter Eschbach , Joel Miscall , Lucas D. Ellis","doi":"10.1016/j.jcat.2025.116070","DOIUrl":"10.1016/j.jcat.2025.116070","url":null,"abstract":"<div><div>Recent proposed approaches in the depolymerization of waste plastics employ an olefin intermediate to produce alkanes or alkenes using olefin metathesis in tandem chemistry. Here we investigated the role of the dehydrogenation catalyst on reaction rate, kinetics, and product distribution in heterogeneous tandem dehydrogenation and olefin metathesis (alkane metathesis) of three different alkane reactants, including polyethylene. We found that many properties to which alkane dehydrogenation rates were sensitive—including metal composition, nanoparticle size, and surface doping of Re species also controlled activity in Tandem D/OM. When comparing Pd, Pt, and Pt3Sn1, supported Pd in tandem with a Re2O7 olefin metathesis catalyst showed four-fold higher activity (surface area basis) compared to Pt or Pt3Sn1 catalysts on the same support, mainly due to differences in the rate of hydrogenation. Catalyst preparation resulted in metal nanoparticles partially covered by ReOx, as seen from elemental mapping. Co-location of Re2O7 and Pd correlated with increased rates of hydrogenation (i.e., an increase in the rate of alkane formation and simultaneous lowering of the rate of alkene formation), with a reaction order in catalyst study that further supported this conclusion. The Pd and Re2O7 system displayed marked improvement compared to Pt or Pt3Sn1 with Re2O7, and previous work, in the depolymerization rate of a linear polyethylene feedstock, with over 94 % reduction in polymer molecular weight in 15 h at 190 °C using less catalyst and increased reactant loadings, while keeping solvent to polymer consumption below 2.5.</div></div>","PeriodicalId":346,"journal":{"name":"Journal of Catalysis","volume":"447 ","pages":"Article 116070"},"PeriodicalIF":6.5,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666298","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}

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Enantioselective synthesis of silicon-stereogenic siladihydrofuran via copper-catalyzed Si-C bond cleavage 铜催化Si-C键裂解对映选择性合成硅立体硅二氢呋喃

IF 6.5 1区化学

Journal of Catalysis Pub Date : 2025-03-20 DOI: 10.1016/j.jcat.2025.116089

Chuang-Chuang Su , Yong-Shun Wu , Pan-Pan Chen , An-Jiu Wen , Zheng Xu , Fei Ye , Jian Cao , Li-Wen Xu

引用次数: 0