ACS Catalysis 最新文献

{"title":"Enhancing the Reactivity of Cu/Al2O3 for Methanol Steam Reforming through adding CrOx: Unraveling Reaction Pathways and the Mechanism for Improvement","authors":"Lifang Jiang, Shaoteng Yuan, Jiamei Ma, Shaorong Deng, Xiuzhong Fang, Xianglan Xu, Hao Meng, Xiang Wang","doi":"10.1021/acscatal.5c00438","DOIUrl":"https://doi.org/10.1021/acscatal.5c00438","url":null,"abstract":"Copper-based catalysts are widely utilized for methanol steam reforming (MSR) reactions. However, improving their performance and achieving a deeper understanding of the reaction mechanism remain significant challenges. Herein, a series of Cu-<i>y</i>%CrO_<i>x</i>/Al₂O₃ catalysts were synthesized. The optimal Cu-7%CrO_<i>x</i>/Al₂O₃ catalyst achieved a high CH₃OH conversion of 93.2%, a low CO selectivity of 0.16%, and a competitive hydrogen production rate of 1142.7 mmol g_cat^–1 h^–1 at 260 °C with a weight space velocity of 14.6 h^–1, significantly outperforming the Cu/Al₂O₃ catalyst. Combined <i>in situ</i> spectroscopy and surface reaction experiments revealed that the MSR reaction on both catalysts predominantly followed the HCOO* pathway. This involves the dehydrogenation of CH₃OH to CH₃O*, followed by oxidation to HCOO*, and then decomposition to produce H₂ and CO₂, with the conversion of CH₃O* to HCOO* being the rate-determining step (RDS). The steam acted as a promoter for the conversions of CH₃O* and HCOO*. A small amount of formaldehyde (HCHO) derived from CH₃O* dehydrogenation tends to dissociate, forming the byproduct CO rather than converting to HCOO*. Due to the promoting effect of CrO_<i>x</i>, improved Cu dispersion, the Cu⁺/Cu⁰ ratio of around 1.0, and increased active oxygen species facilitate the RDS of CH₃O* to HCOO* and the oxidation of CO, leading to an enhanced hydrogen production rate and CO₂ selectivity on Cu-7%CrO_<i>x</i>/Al₂O₃ compared to Cu/Al₂O₃.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"90 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842109","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":"Proximity Effects in Electronic Metal–Support Interactions: O-Vacancy Formation and CO Adsorption on Ru/ZrO2 Model Catalysts","authors":"Mengru Li, Axel Groß, R. Jürgen Behm","doi":"10.1021/acscatal.5c00519","DOIUrl":"https://doi.org/10.1021/acscatal.5c00519","url":null,"abstract":"Continuing our investigation of electronic metal–support interactions (EMSIs) in heterogeneous catalysis, we have investigated the influence of the position and the number of O-vacancies on their stabilization by the Ru nanorod, on the charge transfer from the support to the metal, and on CO adsorption on the Ru nanorod. Employing density functional theory-based calculations and using a model system consisting of a ZrO₂(111) support and a three-layer Ru nanorod, we find that O-vacancies are significantly stabilized only if they are in direct contact with the Ru nanorod, with the extent of stabilization depending on the distance between vacancy and the nearest Ru atom at the interface. Vacancy formation beside the Ru nanorod or in deeper layers of the support is not enhanced by the metal. The Ru-induced stabilization of the O-vacancies is closely coupled with the charge transfer from the support to the metal upon vacancy formation, which is true also in the presence of neighboring O-vacancies. The CO adsorption energy can be substantially modified by four characteristic effects, including charge transfer from the support to the metal, coordination effects, a combination of CO_ad-induced deformation energies and changes in the interface energy and direct interactions between CO and partly reduced Zr surface ions directly neighboring to an O-vacancy, depending on the adsorption site and on the number and positions of the O-vacancies. Thus, it is not possible to completely describe the adsorption properties by using the d-band model, in particular, not for adsorption on the interface sites. The general relevance of these findings for adsorption and catalytic reactions is discussed.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"128 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842110","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":"Enhancing Deep Mineralization and Chlorine Resistance in Methyl Ethyl Ketone Destruction by Taming Synergy of WOx and Pd Sites","authors":"Chunli Ai, Fan Dang, Jialei Wan, Zeyu Jiang, Yani Wu, Jicheng Liu, Han Xu, Yadi Wang, Yanfei Jian, Mingjiao Tian, Changwei Chen, Yanke Yu, Chi He","doi":"10.1021/acscatal.5c00528","DOIUrl":"https://doi.org/10.1021/acscatal.5c00528","url":null,"abstract":"Accelerating deep oxidation while restraining the hazardous intermediate formation remains a great challenge in oxygenated volatile organic compounds (OVOCs) catalytic purification. Herein, we found that the modulation of electronic metal–support interactions (EMSIs) in Pd/WO_<i>x</i>/Al₂O₃ catalysts significantly facilitates the deep oxidation of methyl ethyl ketone (MEK) and markedly enhances the CO₂ selectivity. Over the Pd/WO_<i>x</i>/Al₂O₃ catalyst, 90% of MEK can be fully oxidized at just 140 °C with a low apparent activation energy (<i>E</i>_a) of 19.65 kJ·mol^–1, much superior to that of the commercial Pd/Al₂O₃ catalyst (<i>E</i>_a of 80.81 kJ·mol^–1). The EMSIs promote charge redistribution through the unified Pd-WO_<i>x</i> sites, which modulates the <i>d</i>-band structure of highly dispersed Pd sites and strengthens the adsorption and activation of reactants. The positively charged Pd²⁺ species are dominant in activating MEK molecules at low temperatures, and the stretched W–O bonds enhance the activation of lattice oxygen species to participate in subsequent oxidation, ensuring the rapid total oxidation of MEK molecules via the Mars-van Krevelen mechanism. Furthermore, the bifunctional Pd-WO_<i>x</i> sites can also facilitate the dissociation of H₂O and CH₂Cl₂ molecules, enhancing the water-vapor and chlorine resistance of the Pd/WO_<i>x</i>/Al₂O₃ catalyst, which expands the potential toward practical applications. This work sheds significant guidance for researchers to engineer efficacious catalysts toward industrial OVOCs deep elimination.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"30 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846741","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":"Palladium-Catalyzed Enantioselective Intramolecular Heck Reaction to Access Chiral C3-Tertiary Indolines","authors":"Tao Liu, Tuanli Yao, Ran Fang, Xiangyang Qin","doi":"10.1021/acscatal.5c01282","DOIUrl":"https://doi.org/10.1021/acscatal.5c01282","url":null,"abstract":"Chiral C3-tertiary indolines serve as crucial structural scaffolds in biologically active molecules and natural products. However, the asymmetric synthesis of such compounds remains largely underexplored. In this work, we report a palladium-catalyzed intramolecular Heck strategy that can override the intrinsic aromatization and enable selective access to enantiomerically enriched 3-(2-oxoethyl)indolines (up to 96% ee). The key to the success of this strategy is introducing a hydroxy group at the α-position of alkene moieties of <i>N</i>-allyl-2-iodoanilines, which undergo regioselective β-hydride elimination. We demonstrate the synthetic utility of this strategy by performing downstream transformations of the products based on aldehyde groups. Density functional theory (DFT) calculations elucidate the mechanism and stereoinduction.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"17 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846670","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":"A Photocatalytic Approach to Radical 1-(Trifluoromethyl)cyclopropanation","authors":"Sven Timmann, Moritz T. H. Dilchert, Jörg Dietzel, Verena S. Pöltl, Marc R. Wennekamp, Christopher Golz, Manuel Alcarazo","doi":"10.1021/acscatal.5c01642","DOIUrl":"https://doi.org/10.1021/acscatal.5c01642","url":null,"abstract":"A simple protocol for the multigram-scale synthesis of 5-(1-(trifluoromethyl)cyclopropyl)dibenzothiophenium triflate is reported. This benchtop-stable reagent efficiently releases 1-(trifluoromethyl)cyclopropyl radicals under mild photochemical conditions, enabling the straightforward incorporation of that privileged chemotype at previously nonfunctionalized positions of (hetero)arenes and silyl enol ethers. The trifluoromethylcyclopropanation protocols herein reported are associated with an exceedingly broad substrate scope, remarkable functional group compatibility, high regioselectivity, and synthetically useful yields, making this reagent especially suitable for the preparation of medicinally relevant building blocks.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"47 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849893","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":"Modular and Regioselective Synthesis of Eight-Membered Benzosilacycles Enabled by Ring Expansion of Silacyclobutanes with Aryl Halides and Alkynes","authors":"Zhenzhen Guo, Jinxiang Ye, Yingying Zhang, Danni Wang, Xiaoqian Yu, Chong Li, Yangjie Wu, Ze-Shui Liu","doi":"10.1021/acscatal.5c01177","DOIUrl":"https://doi.org/10.1021/acscatal.5c01177","url":null,"abstract":"Silacycles are essential structural motifs in silicon-containing functional molecules, which are widely applied in the fields of synthetic chemistry, materials science, and pharmaceuticals. However, the synthesis of silacycles especially medium-sized ones remains a formidable challenge. Herein, we report a general and modular platform technology for the construction of eight-membered benzosilacycles by palladium-catalyzed alkyne insertion/C–H activation/ring expansion cascade. Readily available aryl halides, alkynes, and silacyclobutanes are used as the building blocks, laying the foundation for the diversity-oriented synthesis of these scaffolds (&gt;80 examples). Other features include excellent regioselectivities and chemoselectivities, broad functional group tolerance, good step economy, and scalability. This method is also amenable for the synthesis of fused benzosilacycles and dibenzosilacycles that are otherwise difficult to access. Additionally, the reaction mechanism and the origins of regioselectivity are elucidated by control experiments and density functional theory calculations.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"121 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143837428","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":"A KAS III-like Enzyme and an Amidohydrolase in Nataxazole Biosynthesis Direct Formation of the Benzoheterocycle Moiety","authors":"Qian Zhang, Yixin Zhang, Zixin Deng, Yi Yu","doi":"10.1021/acscatal.5c00835","DOIUrl":"https://doi.org/10.1021/acscatal.5c00835","url":null,"abstract":"Benzoxazole is an important heterocycle building block frequently found in medicinal compounds and naturally occurring alkaloids. Deciphering the biosynthetic machinery of benzoxazole would facilitate the efficient synthesis of benzoxazole-based drugs. Nataxazole represents a unique alkaloid class containing two benzoxazole moieties (A and B). Previous studies have established the enzymatic mechanism underlying the biosynthesis of benzoxazole moiety A (fusion of two 3-hydroxyanthranilic acid molecules). Here, we report that the same biosynthetic machinery of nataxazole employs a different logic, which involves a 3-oxoacyl-ACP synthase III-like enzyme (NatS), to assemble benzoxazole moiety B (fusion of 3-hydroxyanthranilic acid with 6-methylsalicylic acid). Biochemical and structural characterization indicated that NatS catalyzes a transacylation reaction to generate an unstable ester intermediate, which immediately undergoes cyclization and dehydration catalyzed by the amidohydrolase NatAM to give benzoxazole moiety B. Interestingly, NatS can also catalyze C–N and C–S bond formation and exhibits remarkable substrate promiscuity, inspiring us to synthesize various benzoheterocycles following the assembly logic of moiety B. Together with our investigation into the biosynthesis of nataxazole analogue A33853, we further identified two key amino acids responsible for NatAM’s substrate recognition to generate two benzoxazole moieties in nataxazole. Finally, we successfully developed a chemoenzymatic approach to produce transthyretin stabilizer Tafamidis (Vyndamax). Therefore, our study found the missing piece of the benzoxazole biosynthesis puzzle, providing a promising strategy to create diverse types of benzoheterocycle compounds.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"27 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842116","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":"Assessing the Influence of Void Environment in MFI Zeolites on Propene Oligomerization Kinetics Using a Combined Computational and Experimental Approach","authors":"Lauren Kilburn, Diamarys Salomé Rivera, Elizabeth E. Bickel Rogers, Rajamani Gounder, David D. Hibbitts","doi":"10.1021/acscatal.5c00392","DOIUrl":"https://doi.org/10.1021/acscatal.5c00392","url":null,"abstract":"The consequences of Brønsted acid site location in MFI zeolites were investigated for propene oligomerization. Adsorbates in MFI may reside in smaller channels (∼5.5 Å diam.) or larger channel intersections (∼7 Å diam.), with tighter confinement expected to enhance both stabilizing dispersive interactions and destabilizing steric constraints. MFI samples synthesized using tetrapropylammonium (TPA⁺) as the structure directing agent have higher fractions of acid sites near intersections, while samples synthesized with 1,4-diazabicyclo[2.2.2]octane (DABCO) or ethylenediamine (EDA) have higher fractions of acid sites within channels. Measured propene dimerization rates (per H⁺, 315 kPa C₃H₆, 503 K, 1.6 H⁺/u.c.) are ∼9 times higher on MFI-DABCO/MFI-EDA than MFI-TPA. Because propene oligomerization is transport-limited in MFI at these conditions, experimentally measured rates are proportional to both effective kinetic (<i>k</i>_eff) and diffusion (<i>D</i>_e) constants. DFT was therefore used to investigate the kinetic influences of void environment in isolation of transport effects. Adsorption free energies for C₃ and C₆ alkenes and dimerization free energy barriers were calculated at all 12 T-sites present in the MFI framework and all accessible O-sites around each T-site. C₃ preferentially adsorbs as H-bonded propene with similar energies in all void environments, while C₆ alkenes are destabilized by 10–56 kJ mol^–1 and dimerization transition states are destabilized by 29–102 kJ mol^–1, on average, in the channels relative to intersections. The stability of C₃ and C₆ alkenes and dimerization transition states is largely governed by steric penalties arising from distortion of the MFI framework that outweigh stronger dispersive interactions with decreasing void size, even for species as small as C₃. Given that DFT predicts <i>k</i>_eff values are lower at acid sites in smaller channel voids of MFI, higher measured rates on MFI samples synthesized using DABCO or EDA must reflect less severe diffusion restrictions and, in turn, higher <i>D</i>_e values.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"75 2 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842115","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-CF3-bipyridine Ligands for the Iridium-Catalyzed Borylation of N-Methylamides","authors":"Daniel Marcos-Atanes, Gonzalo Jiménez-Osés, José L. Mascareñas","doi":"10.1021/acscatal.5c00933","DOIUrl":"https://doi.org/10.1021/acscatal.5c00933","url":null,"abstract":"Bipyridine and phenanthroline are well-established neutral ligands for promoting iridium-catalyzed borylations of aromatic C–H bonds. However, their use with aliphatic substrates is almost uncharted. Herein we demonstrate that introducing CF substituents at the 5- and 5′-positions of bipyridine generates ligands that enable an efficient and regioselective iridium-catalyzed borylation of the methyl group in a broad variety of methylamides. The reaction shows broad functional group tolerance and exhibits remarkable selectivity, offering a powerful approach for the borylation of challenging aliphatic C–H bonds. Mechanistic investigations, including computational analysis, suggest that the accelerating effect of the ligand is likely associated with the formation of non-covalent dispersion interactions between the carbonyl amide of the substrates and the trifluoromethylated pyridine rings of the ligand.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"67 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842119","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":"Visible-Light-Driven Borylacylation of Alkenes by NHC/Photoredox Dual Catalysis: Accessing Boryl 1,4-Dicarbonyl Architectures","authors":"Ze-Le Chen, Shu-Chao Ma, Shou-Yang Tang, Hao-Yu Yu, Yu Zhao, Jun Xuan","doi":"10.1021/acscatal.5c01396","DOIUrl":"https://doi.org/10.1021/acscatal.5c01396","url":null,"abstract":"Boron-containing carbonyl compounds serve as versatile synthons in organic synthesis, materials science, and medicinal chemistry, with boryl dicarbonyl compounds emerging as privileged precursors for the construction of borylated heterocycles. Despite their utility, efficient synthesis of these architectures from readily available starting materials remains challenging, particularly those requiring concurrent borylation and acylation. Herein, we present a transition-metal-free strategy for modular assembly of boryl 1,4-dicarbonyl compounds via synergistic photoredox/<i>N</i>-heterocyclic carbene (NHC) dual catalysis. The reaction proceeds through regioselective alkene difunctionalization involving NHC-attached ketyl and NHC-boryl radicals, achieving good chemo- and diastereoselectivity. This protocol demonstrates broad functional group tolerance (44 examples) and scalability (gram-scale synthesis), while mechanistic studies (radical blocking and electron paramagnetic resonance (EPR) detection) corroborate the generation and coupling of two radical species. The synthetic versatility is further highlighted by downstream transformations into pharmaceutically relevant multisubstituted boryl γ-lactones and 1,2-benzazaborines.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"25 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842120","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}