Reaction Chemistry & Engineering最新文献

{"title":"Effect of defects and framework Sn on the stability and activity of Pt clusters for ethane dehydrogenation in chabazite zeolite†","authors":"Sanjana Srinivas, Dionisios G. Vlachos and Stavros Caratzoulas","doi":"10.1039/D4RE00187G","DOIUrl":"10.1039/D4RE00187G","url":null,"abstract":"<p >With increasing interest in new catalytic materials based on atomically dispersed transition metals on various supports (<em>e.g.</em>, zeolites or oxides), it is necessary to have an atomic level understanding of the factors that determine their structural and electronic properties as well as catalytic activity. Encapsulated Pt atoms and sub-nanometer Pt clusters in Sn-substituted zeolitic frameworks have demonstrated extended catalytic stability and remarkable selectivity for alkane dehydrogenation to alkenes. Despite efforts to characterize these materials, the bonding environment of the dispersed atoms in the presence of framework Sn or of defect silanols is uncertain. We have employed <em>ab initio</em> molecular dynamics simulations and electronic structure calculations to identify and characterize electronically stable Pt active site motifs in chabazite (CHA) and Sn-CHA at low Pt loadings. The activity of several active site motifs was assessed by microkinetic simulations. We demonstrate that framework Sn and silanol defects can promote the dispersion of Pt species. Unexpectedly, we find that in the presence of silanol nests, the dispersed Pt species statistically prefer to coordinate with the silanols and not with the framework Sn. We show that Pt and Sn are bonded <em>via</em> a 3-center-4-electron bond (O:–Sn–:Pt), affirm the absence of Pt–O–Sn bonding, and thus resolve the ambiguity related to the coordination of Pt to framework Sn. We predict that the O:–Sn–:Pt and Sn–O–Pt–Pt–Si bonding motifs in Sn-CHA are stable and active for ethane dehydrogenation. We relate our findings and conclusions to recent experimental characterization of Pt in Sn-BEA zeolite, point out the close alignment in several aspects and suggest that the effect of framework Sn on the dispersion of low nuclearity Pt species and on the formation of stable and efficient active sites should be largely independent of the framework itself.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 10","pages":" 2784-2793"},"PeriodicalIF":3.4,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/re/d4re00187g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141949277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of thermal dry reforming of methane for syngas production and solid carbon capture†","authors":"Manas Mokashi, Akash Bhimrao Shirsath, Sinan Demir, Ahmet Çelik, Patrick Lott, Steffen Tischer and Olaf Deutschmann","doi":"10.1039/D4RE00312H","DOIUrl":"10.1039/D4RE00312H","url":null,"abstract":"<p >Dry reforming of CH<small>₄</small>, either by co-feeding CH<small>₄</small> and CO<small>₂</small> from waste streams or directly using biogas, has potential as a CO<small>₂</small>-sink. This study investigates entirely thermal, catalyst-free dry reforming in a tubular flow reactor, aiming for syngas production with concurrent carbon capture. Kinetic modelling couples an elementary step-based gas-phase mechanism with a carbon deposition model. One-dimensional numerical simulations of the flow reactor are compared with experimental measurements. For this, operating conditions are widely varied, in particular temperature (1273 K to 1873 K), residence time (1 to 7 seconds), and CH<small>₄</small> : CO<small>₂</small> molar feed ratio (1 to 4). Two temperature regimes are identified, with varying dominance of the reverse water-gas shift and CH<small>₄</small> pyrolysis reactions. Above 1673 K, CO<small>₂</small> is fully consumed, independent of residence time and feed composition. Optimized operating parameters result in a H<small>₂</small>/CO ratio of 2 in the effluent gas stream, <em>e.g.</em> as commonly desired for methanol and oxo-alcohol synthesis. Notably, under such optimized conditions, only a minor share of carbonaceous species remains in the gas-phase as hydrocarbons, while 33% of the CH<small>₄</small>-borne carbon is transformed into CO and 48% of CH<small>₄</small>-borne carbon is captured as solid carbon.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 11","pages":" 2902-2914"},"PeriodicalIF":3.4,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/re/d4re00312h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141949279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D printing for safe organic synthesis in mixed liquid/gas-phase chemistry","authors":"Victoria A. Korabelnikova, Yulia V. Gyrdymova, Evgeniy G. Gordeev, Anton N. Potorochenko, Konstantin S. Rodygin, Valentine P. Ananikov","doi":"10.1039/d4re00249k","DOIUrl":"https://doi.org/10.1039/d4re00249k","url":null,"abstract":"Working with liquid/gas-phase systems in chemical laboratories is a fundamentally important but difficult operation, mainly due to the explosion risk associated with conventional laboratory equipment. Such systems, in the case of improper operation or destruction, may pose a significant threat to researchers. To address this challenge, our work explores the potential of additive technologies, particularly fused filament fabrication (FFF), for improving laboratory safety. We have successfully utilized FFF to produce compact safety modules, including integrated bursting discs, which can be easily made on demand and adapted to various types of reaction setups. Compared with traditional glassware, these modules, when integrated with laboratory reactors, significantly enhance operational safety. Our research highlights that in the event of excessive internal pressure, 3D-printed reactor parts undergo delamination and cracking of the wall, a mechanism that notably avoids the creation of hazardous fragments from the whole reaction vessel. This study demonstrated the efficiency and safety of additively manufactured reactors in organic synthesis using a variety of gases, including acetylene, carbon dioxide, and hydrogen. We systematically tested these reactors in vinylation and azide–alkyne cycloaddition reactions. Our findings confirm that 3D-printed reactors not only provide increased safety during pressurized operations but also maintain operational efficiency. The discussed approach offers a transformative solution for safer and more effective handling of gaseous reagents in laboratory settings, marking a significant advancement in flexible reactor design and chemical laboratory safety practices.","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":"294 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141949280","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}

{"title":"Modular 3D printed flow system for efficient one-step synthesis of phenyl-functionalised silica-coated superparamagnetic iron oxide nanoparticles†","authors":"Andrea du Preez, André M. Strydom, Derek T. Ndinteh and Elize Smit","doi":"10.1039/D4RE00242C","DOIUrl":"10.1039/D4RE00242C","url":null,"abstract":"<p >Iron oxide nanoparticles (IONPs) are used in various applications, including magnetic solid phase extraction (MSPE), due to advantages such as excellent adsorption efficiency and easy separation from varied matrices using an external magnet. Here we introduce a low-cost 3D-printed modular flow system for the automated synthesis of phenyl-functionalised silica-coated iron oxide nanoparticles. This system consists of 3D-printed polypropylene (PP) reactors with varying geometries connected in series to synthesise bare IONPs, silica-coated IONPs, or phenyl-functionalised silica-coated IONPs using laminar flow regimes. The simplicity, affordability, robustness, and customisability of the system were illustrated. The synthesised IONPs were characterised using Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), zeta potential, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The continuous flow system resulted in fast reactions under ambient conditions, with a production rate of approximately 5 mg min<small>⁻¹</small>. The produced IONPs were small (∼10 nm), resulting in a larger surface-to-volume ratio. Furthermore, the synthesised IONPs retained large enough saturation magnetisation values, which together with larger surface-to-volume ratios, is ideal for MSPE.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 10","pages":" 2740-2749"},"PeriodicalIF":3.4,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/re/d4re00242c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Propane dehydrogenation on an extra-framework and framework-embedded metal site within ZSM-5 zeolite from first-principles microkinetic simulations†","authors":"Yujue Du, Wende Hu, Yunlei Chen, Chuanming Wang and Weimin Yang","doi":"10.1039/D4RE00269E","DOIUrl":"10.1039/D4RE00269E","url":null,"abstract":"<p >Isolated single metal site within zeolite exhibits promising catalytic performances towards propane dehydrogenation (PDH); however, the underlying relationship between the local structure of the intrinsic site and the catalytic behavior remains elusive. Herein, the possible structures, relative stabilities and catalytic performances of three isolated single metal cations (M<small>²⁺</small>, M is Co, Ni, or Cu) within ZSM-5 zeolite were theoretically investigated by combining density functional theory calculations and microkinetic simulations. Both the extra-framework site and the framework-embedded site were taken into account for the sitting of a single metal cation. The isolated divalent M<small>²⁺</small> sites are more stable than the corresponding univalent MOH<small>⁺</small> sites and both kinds of structures display distinct dependence of stability on temperature. The stepwise pathway rather than the concerted pathway is followed for direct PDH under the reaction conditions of 853 K. Microkinetic simulations reveal that PDH activity increases in the sequence of Co &lt; Ni &lt; Cu within the same local environment of the active site. At the framework-embedded site, the divalent M<small>²⁺</small> cations exhibit higher catalytic activity compared to univalent MOH<small>⁺</small> cations; on the contrary, the MOH<small>⁺</small> motifs are more active than the divalent M<small>²⁺</small> ones at the extra-framework site. It seems that the dissociative adsorption enthalpy of propane on isolated metal sites can be utilized to describe PDH activity variation with different metal cations. Simulation results demonstrate that the framework-embedded single Cu site derived from the silanol nest within ZSM-5 zeolite exhibits outstanding PDH activity, while it may suffer from the weakness of stability. This work thus highlights the importance of the local environment of single metal active sites within zeolites and may open up novel avenues for the screening of high-performance catalysts for PDH.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 11","pages":" 2892-2901"},"PeriodicalIF":3.4,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885125","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}

{"title":"Correction: Parameter investigation of an organic–inorganic hybrid resin for a 3D-printed microchannel heat exchanger","authors":"Sunjae Lee, Amirreza Mottafegh and Dong-Pyo Kim","doi":"10.1039/D4RE90029D","DOIUrl":"10.1039/D4RE90029D","url":null,"abstract":"<p >Correction for ‘Parameter investigation of an organic–inorganic hybrid resin for a 3D-printed microchannel heat exchanger’ by Sunjae Lee <em>et al.</em>, <em>React. Chem. Eng.</em>, 2024, <strong>9</strong>, 2089–2097, https://doi.org/10.1039/D3RE00694H.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 9","pages":" 2520-2520"},"PeriodicalIF":3.4,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/re/d4re90029d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microdroplet chemical reactor prototype based on multiplexed electrospray†","authors":"Denis O. Kuleshov, Ivan A. Gromov, Ilya I. Pikovskoi, Alexandra A. Onuchina, Ilya S. Voronov, Dmitrii M. Mazur and Albert T. Lebedev","doi":"10.1039/D4RE00264D","DOIUrl":"10.1039/D4RE00264D","url":null,"abstract":"<p >The advent of ambient mass spectrometry has yielded novel approaches to chemical transformations for analytical and preparative applications. These methods utilize the microdroplets generated <em>via</em> spray ionization techniques. Numerous studies have demonstrated the superior efficiency of microdroplet-based chemical reactions. This efficiency is manifested in a substantial acceleration of reactions (up to a million-fold compared to bulk reactions) and a shift in reaction pathways, enabling the synthesis of compounds that are challenging to obtain using conventional methods. However, the widespread implementation of this approach has been hindered by its limited productivity. To address this challenge, this paper introduces a microdroplet chemical reactor prototype (MCR prototype) that employs multiplexed pneumatic/electrospray to enhance productivity. The performance of the MCR prototype was evaluated using the cyclohexanone phenylhydrazone synthesis reaction from phenylhydrazine and cyclohexanone in methanol as a model system. The prototype demonstrated a significant acceleration of the reaction relative to its occurrence in bulk, with the apparent acceleration factor (AAF) exceeding a value of 83 × 10<small>⁶</small>. The MCR prototype can spray the reaction mixture at a rate of up to 17 mL min<small>⁻¹</small> while maintaining the acceleration effect, achieving a productivity of grams per hour. This prototype offers a promising solution for addressing practical and research challenges in microdroplet chemical synthesis.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 10","pages":" 2683-2690"},"PeriodicalIF":3.4,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885124","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}

{"title":"Process knowledge for drug substance production via kinetic modeling, parameter estimability analysis and reaction optimization†","authors":"Iman Moshiritabrizi, Jonathan P. McMullen, Brian M. Wyvratt and Kimberley B. McAuley","doi":"10.1039/D4RE00210E","DOIUrl":"10.1039/D4RE00210E","url":null,"abstract":"<p >A mechanistic model is developed to study the formation of 2,6-difluoropurine-9-THP from starting material 2,6-dichloropurine-9-THP. The 2,6-difluoropurine-9-THP product is an intermediate used in the synthesis of islatravir (MK-8591), a therapy for treatment of HIV. Kinetic parameters are estimated from 26 batch reactor experiments. An error-in-variables-model (EVM) approach is used for parameter estimation to address uncertainty in initial concentrations of trimethylamine (TMA), a gaseous reagent. A parameter subset selection method is used to determine that 33 out of 39 model parameters should be estimated along with 26 uncertain initial concentrations. The remaining six parameters are kept at their initial values to prevent overfitting of available data. EVM parameter estimates are compared with estimates obtained using a traditional weighted-least-squares approach that neglects input uncertainties. The EVM estimates provide a better fit to the data and, as shown using cross-validation, improved accuracy for model predictions. The resulting model and EVM parameter values are used to find reactor conditions that maximize product yield while obeying constraints on temperature, the initial ratio of TMA to starting material, batch time, and the volume of solvent. An optimal yield of 92.04% is predicted, which is higher than the yield of 90.26% at the best experimental conditions in the data set. Contour plots are used to highlight the insensitivity of the optimal yield to batch time and solvent volume, indicating that a yield of 91.83% could be obtained using a 50% lower batch time and 33% less solvent.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 10","pages":" 2669-2682"},"PeriodicalIF":3.4,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885126","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}

{"title":"Evaluating metal-free quaternized boronate esters as efficient catalysts for the fixation of CO2 with epoxides to form cyclic carbonates under suitable conditions†","authors":"Eyyup Yasar, Emine Aytar and Ahmet Kilic","doi":"10.1039/D4RE00282B","DOIUrl":"10.1039/D4RE00282B","url":null,"abstract":"<p >The conversion of CO<small>₂</small> into high value-added chemicals is receiving increasing attention from the scientific community, commercial enterprises, and policymakers due to environmental problems like global warming. Herein, metal-free quaternized boronate esters (<strong>QBE</strong><small>_{<strong>1</strong>}</small>–<strong>QBE</strong><small>_{<strong>8</strong>}</small>) were prepared and then used as potential efficient metal-free catalysts for the chemical valorization of CO<small>₂</small> to organic cyclic carbonates under solvent-free and sustainable green atmospheric and high-pressure conditions (1 atm or 1.6 MPa, 100 °C, 2 h) as an alternative to toxic reagents such as phosgene. Analyses performed with various spectroscopic tools (<small>¹</small>H, <small>¹³</small>C, and <small>¹¹</small>B NMR, FT-IR, UV-vis, LC-MS/MS, elemental analysis, and melting point measurement together with thermal gravimetric analysis (TGA-DTA)) revealed that the targeted quaternized boronate esters were successfully synthesized. After that, the Lewis acidity of the synthesized quaternized boronate esters was investigated by the traditional Gutmann–Beckett method and found to range from 53.72 to 50.47 ppm, respectively. In the presence of 0.1 mol% metal-free quaternized boronate ester <strong>QBE</strong><small>_{<strong>3</strong>}</small> and 0.2 mol% co-catalyst DMAP, 4-chloromethyl-1,3-dioxalan-2-one was obtained as a cyclic carbonate in 51.7% yield at 1 atm and 100 °C and then under 1.6 MPa and 100 °C in an excellent 94.9% yield with 97.9% selectivity in 2 h, allowing us to facilitate the fixation of CO<small>₂</small> into cyclic carbonates rapidly. According to the catalytic findings, the optimum cat./ECH ratio for CO<small>₂</small> cycloaddition reactions is 1/1000.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 11","pages":" 2938-2953"},"PeriodicalIF":3.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141862697","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}

{"title":"The graph automorphism group of the dissociation microequilibrium of polyprotic acids","authors":"Nicolás Salas, Justin López and Carlos A. Arango","doi":"10.1039/D4RE00271G","DOIUrl":"10.1039/D4RE00271G","url":null,"abstract":"<p >The dissociation micro-states (DMSs) of an <em>N</em>-protic acid are described using set theory notation, which facilitates the mathematical description of the dissociation micro-equilibrium (DME). In particular, the DME constants are easily obtained in terms of the dissociation equilibrium constants and the molar fractions of the DMSs. Representing the DME in terms of graph theory allows us to identify permutations between DMSs that preserve the vertex-edge connectivity of the graph. These permutations, along with their compositions, led to the identification of the direct product <em>C</em><small>₂</small> × <em>S</em><small>_<em>N</em></small> of the cyclic group <em>C</em><small>₂</small> and the symmetric group <em>S</em><small>_<em>N</em></small> as the graph automorphism group of the microdissociation of <em>N</em>-protic acids with <em>N</em> = 1, 2, …, 6. In this context, the microdissociations are associated with the <em>C</em><small>₂</small> group while the tautomerizations are related to the <em>S</em><small>_<em>N</em></small> group.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 11","pages":" 2925-2937"},"PeriodicalIF":3.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141862701","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}