{"title":"Development of site- and stereoselective continuous flow deuterium labelling method for carbohydrates using high dispersion effect towards Ru/C of hydrogen flow†","authors":"Naoya Sakurada, Daiki Sasaki, Manato Ono, Tsuyoshi Yamada, Takashi Ikawa and Hironao Sajiki","doi":"10.1039/D5RE00026B","DOIUrl":"https://doi.org/10.1039/D5RE00026B","url":null,"abstract":"<p >A site- and stereoselective deuterium labelling method for carbohydrates has been developed using a Ru/C catalyst under continuous flow conditions. It has been demonstrated that enhancing the void fraction of the catalyst cartridge leads to improved incorporation, while maintaining high selectivity over 150 h. This scalable, sustainable approach has the potential to reduce energy use, waste and Ru consumption, thus broadening continuous flow applications in organic synthesis.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 777-781"},"PeriodicalIF":3.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698424","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}
Beatrice Tagliabue, Christian M Heckmann, Rocio Villa, Sacha Grisel, Jean-Guy Berrin, Mickael Lafond, David Ribeaucourt, Caroline E Paul
{"title":"Enantioselective synthesis of (<i>R</i>)-citronellal from geraniol with an immobilised copper alcohol oxidase and ene reductase.","authors":"Beatrice Tagliabue, Christian M Heckmann, Rocio Villa, Sacha Grisel, Jean-Guy Berrin, Mickael Lafond, David Ribeaucourt, Caroline E Paul","doi":"10.1039/d5re00034c","DOIUrl":"https://doi.org/10.1039/d5re00034c","url":null,"abstract":"<p><p>(<i>R</i>)-Citronellal is one of the key chiral intermediates in the synthesis of the isomer (-)-menthol, one of the most commercialised terpenoid flavours worldwide. Enzymatic approaches could represent a less energy-demanding alternative for its synthesis, such as a previously reported bienzymatic cascade starting from inexpensive, commercially available geraniol. A copper radical oxidase (<i>Cgr</i>AlcOx) followed by a flavin-dependent ene reductase (OYE2) were used to obtain (<i>R</i>)-citronellal. Here, we used a metal-affinity immobilisation strategy on the His-tagged enzymes for the cascade and studied enzyme recovery and reusability as well as increased solvent tolerance. After screening a panel of resins for enzyme immobilisation and water-immiscible co-solvents, we successfully obtained 95% conversion to (<i>R</i>)-citronellal with 96.9% enantiomeric excess (ee) in a concurrent cascade after 7 h of reaction time, starting from 10 mM of geraniol.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11908116/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646383","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":"Vapor phase coupling of n-butanol over the mixed catalyst system PdZn/SiO2 + TiO2†","authors":"Evan C. Wegener","doi":"10.1039/D4RE00474D","DOIUrl":"https://doi.org/10.1039/D4RE00474D","url":null,"abstract":"<p >Coupling fermentation derived oxygenates <em>via</em> Guerbet-type reactions offers a potential route for producing fuels and chemicals from agricultural feedstocks. In this work the vapor phase reactions of <em>n</em>-butanol over a bimetallic PdZn/SiO<small><sub>2</sub></small> catalyst and physical mixtures of PdZn/SiO<small><sub>2</sub></small> and TiO<small><sub>2</sub></small> were studied. The bimetallic catalyst was highly selective for n-butanol dehydrogenation without the subsequent decarbonylation of butanal which is characteristic of monometallic Pd nanoparticles. When combined with TiO<small><sub>2</sub></small>, a known aldol condensation catalyst, the bifunctional system performs Guerbet-type coupling reactions and produces mixtures of C<small><sub>8</sub></small> oxygenates and higher-order products including C<small><sub>7</sub></small>, C<small><sub>8</sub></small>, and C<small><sub>12</sub></small> hydrocarbons. Results show that within the reaction network PdZn/SiO<small><sub>2</sub></small> performs dehydrogenation/hydrogenation reactions and decarbonylates C<small><sub>8</sub></small> aldehydes to form C<small><sub>7</sub></small> hydrocarbons. TiO<small><sub>2</sub></small> catalyzes aldol condensation and alcohol dehydration reactions responsible for producing C<small><sub>8</sub></small> and C<small><sub>12</sub></small> hydrocarbons. Based on the developed understanding of the function of each catalyst, it was shown that increasing the Brønsted acidity of the TiO<small><sub>2</sub></small> catalyst resulted in an increase in the production of C<small><sub>8</sub></small> hydrocarbons relative to C<small><sub>12</sub></small> hydrocarbons. This work demonstrates the ability of bimetallic Pd-based catalysts that are selective for alcohol dehydrogenation to participate in Guerbet-type coupling reactions and that their combination with an appropriate aldol condensation/dehydration catalyst is an effective strategy to produce higher molecular weight oxygenates and hydrocarbons from renewable resources.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 906-916"},"PeriodicalIF":3.4,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698410","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":"Superior photocatalytic activity of Mn vanadate/reduced graphene oxide magnetic nanocomposite for the oxidation of methylene blue dye under sunlight irradiation†","authors":"Fatemeh Rahmatpour and Niaz Monadi","doi":"10.1039/D4RE00314D","DOIUrl":"https://doi.org/10.1039/D4RE00314D","url":null,"abstract":"<p >A magnetic photocatalyst based on reduced graphene oxide and semiconducting MnV<small><sub>2</sub></small>O<small><sub>6</sub></small> (rGO/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small>/MnV<small><sub>2</sub></small>O<small><sub>6</sub></small>) was synthesized by magnetizing the rGO/MnV<small><sub>2</sub></small>O<small><sub>6</sub></small> composite for the efficient degradation of methylene blue (MB), a biodegradation-resistant dye. The prepared magnetic photocatalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, Brunauer–Emmett–Teller surface area analysis, Barrett–Joyner–Halenda (BET-BJH) pore analysis and vibrating sample magnetometry (VSM). Its photocatalytic properties and activity were investigated using UV–Vis diffuse reflectance spectroscopy (DRS), fluorescence spectroscopy and inductively-coupled plasma analysis. The synthesized rGO/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small>/MnV<small><sub>2</sub></small>O<small><sub>6</sub></small> nanocomposite exhibited a bandgap of 2.59 eV and a specific surface area of 201.5 m<small><sup>2</sup></small> g<small><sup>−1</sup></small>. The optimum photocatalytic conditions for efficient MB photodegradation were determined, and the photocatalytic efficiency was investigated under different light irradiations, including blue and yellow light as well as sunlight. The rGO/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small>/MnV<small><sub>2</sub></small>O<small><sub>6</sub></small> photocatalyst demonstrated excellent MB degradation efficiency, achieving up to 94% under sunlight irradiation. Additionally, the catalyst exhibited remarkable reusability, maintaining 88% degradation efficiency after the 6th cycle, with negligible structural changes. The magnetic properties of the employed photocatalyst played a key role in facilitating their separation and recycling. The kinetics and mechanism of the photodegradation process were evaluated, revealing a pseudo-first-order rate constant of 0.0882 min<small><sup>−1</sup></small> for a hydroxyl radical-based mechanism. The MB degradation was driven by the generation of superoxide (O<small><sub>2</sub></small>˙<small><sup>−</sup></small>) and hydroxyl (˙OH) free radicals during the reaction.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 876-893"},"PeriodicalIF":3.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698408","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}
E. O. Minyaylo, A. I. Kudryavtseva, M. N. Temnikov, A. S. Peregudov, A. A. Anisimov and A. M. Muzafarov
{"title":"Depolymerization of polydimethylsiloxanes in ammonia – a new approach to silicone recycling†","authors":"E. O. Minyaylo, A. I. Kudryavtseva, M. N. Temnikov, A. S. Peregudov, A. A. Anisimov and A. M. Muzafarov","doi":"10.1039/D4RE00566J","DOIUrl":"https://doi.org/10.1039/D4RE00566J","url":null,"abstract":"<p >This work presents a new approach to recycling silicone waste: depolymerization in ammonia. The optimal depolymerization conditions (150 °C, 0.25 mL H<small><sub>2</sub></small>O, 24 h) to achieve complete polymer conversion were developed using a model siloxane fluid PMS-200. The method performance was demonstrated on model unfilled silicone rubbers obtained by classical methods of curing silicone elastomers such as hydrosilylation, condensation of functional groups and radical polymerization in the presence of benzoyl peroxide. The versatility of this approach for recycling both linear silicones (fluids and gums) and filled rubbers (fillers of different nature) was demonstrated. The completeness of the depolymerization and the analysis of the low molecular weight products were tested by SEC, GC and <small><sup>29</sup></small>Si NMR spectroscopy. The scalability of the process has been demonstrated.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 922-930"},"PeriodicalIF":3.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698412","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}
József Schindler, István Greiner and György Keglevich
{"title":"Energetical analysis of a method for the scale-up of a microwave flow P-esterification by recirculation†","authors":"József Schindler, István Greiner and György Keglevich","doi":"10.1039/D4RE00622D","DOIUrl":"https://doi.org/10.1039/D4RE00622D","url":null,"abstract":"<p >In a previous communication, we described a flow chemical microwave implementation, where the reaction mixture is circulated. In this way, the given reactor capacity can be increased by up to ten times without any special modifications. It was investigated how the flow rate affects the required number of cycles, and hence the time required to achieve the maximum conversion. The role of the ionic liquid catalyst, and the effect of the increase in the volume on the outcomes were also studied. In this paper, we analyse further the data obtained from an energetic point of view. It was observed that the power of the magnetron of the microwave reactor is consumed by the sets marked by higher flow rates and by increased volumes. The direct esterification of phenyl-<em>H</em>-phosphinic acid with butyl alcohol, which has been previously reported under microwave conditions, was chosen as a model reaction.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 856-863"},"PeriodicalIF":3.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698405","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":"Immobilized laccase of Galactomyces geotrichum on modified bentonite and its use in the bioremediation of olive mill wastewater†","authors":"Khadijeh Pourkhanali and Gholam Khayati","doi":"10.1039/D4RE00470A","DOIUrl":"https://doi.org/10.1039/D4RE00470A","url":null,"abstract":"<p >This work investigates the immobilization of laccase obtained from <em>Galactomyces geotrichum</em> onto modified bentonites. The structures of the composites were examined using SEM, FTIR, and BET techniques. Biocatalysts were evaluated in terms of activity, stability and kinetic parameters. Among the immobilized laccases, GDU-bent-lac exhibited the highest efficacy in operational (96% after 10 cycles), thermal (61% within 24 h at 65 °C), and storage (79.69% for 30 days) stabilities. Results suggested that the Langmuir model better correlated with the obtained data than the Freundlich isotherm. Results of the biodegradability study indicated that the increase in the biodegradability index of olive mill wastewater was remarkable when CTAB-bent-lac was used. Additionally, the bulk increase in the biodegradability was related to the support before laccase immobilization (0.43), and moreover, immobilization enhanced the biodegradability to some extent (0.46). In this research, a strong laccase-producing microorganism that was isolated from olive mill wastewater was used for the bioremediation of the same wastewater. To the best of our knowledge, the immobilization of laccase produced by <em>G. geotrichum</em>, isolated from OMW, onto modified bentonites has not been published earlier. Furthermore, the feasibility of using immobilized laccase to increase the biodegradability of OMW was investigated for the first time.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 825-838"},"PeriodicalIF":3.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698429","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":"Identifying the ideal thermodynamics of non-stoichiometric oxygen-carrier materials for chemical looping water-gas shift†","authors":"M. Selim Ungut, Ian S. Metcalfe and Wenting Hu","doi":"10.1039/D4RE00454J","DOIUrl":"https://doi.org/10.1039/D4RE00454J","url":null,"abstract":"<p >With the growth in importance of H<small><sub>2</sub></small> both industrially and as a potential energy vector along the pathway to achieving future environmental sustainability, there is an increasing need for cleaner and more efficient methods of H<small><sub>2</sub></small> production. One promising short-term solution is to perform the water-gas shift reaction for H<small><sub>2</sub></small> production in a chemical looping reactor to produce separate H<small><sub>2</sub></small> and CO<small><sub>2</sub></small> streams, thereby reducing equipment size and the cost of downstream CO<small><sub>2</sub></small> separation. Non-stoichiometric perovskite oxides have been identified as promising oxygen carrier materials (OCMs) for the chemical looping water-gas shift (CLWGS) process as they can be engineered to allow rapid oxygen uptake kinetics, and also benefit from a thermodynamic advantage allowing higher conversions than that of conventional mixed feed reactor systems at the same temperature. The relationship between the oxygen non-stoichiometry of the solid OCM and the equilibrium oxygen partial pressure of the gas phase streams plays an important role in determining the gas conversions and usable oxygen capacity of the OCM. In this work, an optimal relationship between the two material properties in a thermodynamically limited system is proposed, and an equilibrium packed-bed reactor model is used for validation. The effect on conversions was investigated by varying the thermodynamics of the non-stoichiometric material relative to the proposed optimal case. More generally, an analogue of the pinch analysis can be used to analyse chemical looping water-gas shift reactions and similar processes.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 4","pages":" 800-809"},"PeriodicalIF":3.4,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/re/d4re00454j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698427","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}