Lucas Coral Ferreira, Renan de Souza Galaverna, Tom McBride, Rodrigo Costa e Silva, Duncan L. Browne and Julio Cezar Pastre
{"title":"Fast and scalable continuous flow synthesis of butenolides and coumarins†","authors":"Lucas Coral Ferreira, Renan de Souza Galaverna, Tom McBride, Rodrigo Costa e Silva, Duncan L. Browne and Julio Cezar Pastre","doi":"10.1039/D4RE00567H","DOIUrl":"https://doi.org/10.1039/D4RE00567H","url":null,"abstract":"<p >Herein, we present a versatile and efficient continuous flow protocol for the synthesis of structurally diverse butenolides and coumarins through the <em>in situ</em> generation of acylketenes <em>via</em> the retro hetero-Diels–Alder reaction of dioxinones with α-hydroxy-ketones and salicylaldehydes, respectively. This protocol enabled the synthesis of 5 examples of butenolides with yields ranging from 30 to 91% and 16 examples of coumarins with yields ranging from 30 to 99%. The versatility and practicality of the protocol were demonstrated by the gram-scale synthesis of a biologically relevant γ-spiro butenolide core, as well as the production of benzo-coumarins. Modern medicinal chemistry demands both scalability and the ability to synthesize structurally diverse compounds in a single synthetic platform, and our methodology effectively addresses these challenges in a fast and safer manner.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 5","pages":" 1108-1113"},"PeriodicalIF":3.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/re/d4re00567h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888490","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}
Mahendra Kumar Meena, Shalini Biswas and Prakash Biswas
{"title":"Hydrogenation of CO2 to synthetic natural gas (SNG) with 100% selectivity over a Ni–ZnO–MgO catalyst†","authors":"Mahendra Kumar Meena, Shalini Biswas and Prakash Biswas","doi":"10.1039/D4RE00587B","DOIUrl":"https://doi.org/10.1039/D4RE00587B","url":null,"abstract":"<p >The CO<small><sub>2</sub></small> hydrogenation activity of a Ni–ZnO–MgO catalyst prepared by the co-precipitation technique is evaluated in a down-flow tubular reactor. The physicochemical properties of the catalyst were characterized by various techniques, including N<small><sub>2</sub></small>-physisorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), temperature-programmed desorption (TPD), hydrogen chemisorption, FE-SEM, TGA, TEM, XPS, <em>etc.</em> Hydrogenation experiments were performed at different temperatures (200–400 °C) and mild pressure (1–15 bar) at a constant feed gas (H<small><sub>2</sub></small>/CO<small><sub>2</sub></small>/N<small><sub>2</sub></small>) molar ratio of 3 : 1 : 3. The total feed flow rate was maintained at 3 × 10<small><sup>−3</sup></small> mol min<small><sup>−1</sup></small>. Results demonstrated that the Ni–ZnO–MgO catalyst was ∼100% selective to CH<small><sub>4</sub></small>. ZnO helped to improve not only the catalyst stability <em>via</em> hydrogen spillover effect but also the nickel metal dispersion, and MgO enhanced the CO<small><sub>2</sub></small> adsorption. Overall, the reaction mechanism followed the formate species pathway to obtain almost 100% methane selectivity. Time-on-stream study suggested that the catalyst was stable with negligible carbon formation. The used catalyst characterization results showed that the catalyst morphology remained unchanged before and after the reaction. Therefore, the developed Ni–ZnO–MgO catalyst is very promising for the selective hydrogenation of CO<small><sub>2</sub></small> to synthetic natural gas (SNG).</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 5","pages":" 1054-1066"},"PeriodicalIF":3.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888486","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}
Liping Luo, Wenxuan Wu, Yanan Shen, Yuheng Tao, Liqun Wang and Qing Qing
{"title":"An integrated strategy for corncob pretreatment and coproduction of furfural and monosaccharides based on p-toluenesulfonic acid and a deep eutectic solvent system†","authors":"Liping Luo, Wenxuan Wu, Yanan Shen, Yuheng Tao, Liqun Wang and Qing Qing","doi":"10.1039/D4RE00500G","DOIUrl":"https://doi.org/10.1039/D4RE00500G","url":null,"abstract":"<p >High-value valorization of cellulose and hemicellulose fractions in lignocellulosic biomass is crucial for a feasible biomass refinery scheme. In this study, an integrated strategy was developed for pretreatment of corncob and coproduction of furfural and high-concentration fermentable sugars. The hemicellulose fraction in raw corncob was selectively extracted to produce a xylose-rich hydrolysate <em>via</em> pretreatment with dilute <em>p</em>-toluenesulfonic acid (<em>p</em>-TsOH) under optimal reaction conditions (0.5% <em>p</em>-TsOH, 160 °C, and 30 min). Thereafter, the xylose hydrolysate was subjected to catalytic conversion in a DES (TEBAC : LA = 1 : 4) system at 190 °C for 10 min. Notably, 78.6% furfural yield was achieved, and the corresponding xylose conversion was close to 100.0%. In addition, the pretreated corncob residue exhibited excellent enzymatic digestibility as the yields of reducing sugar and glucose were 90.7% and 97.0%, respectively, at a high solid loading of 12%. This proposed approach represents an integrated strategy for coproduction of multiple products from agriculture residues.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 5","pages":" 1096-1107"},"PeriodicalIF":3.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888489","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}
Shuo Ai, Kaili Gao, Zhenhua Huang, Linghui Liu and Wanguo Yu
{"title":"Modification of acidic groups over zeolites via calcination for the selective catalytic transformation of 2,3-butanediol in ethylene glycol","authors":"Shuo Ai, Kaili Gao, Zhenhua Huang, Linghui Liu and Wanguo Yu","doi":"10.1039/D4RE00278D","DOIUrl":"https://doi.org/10.1039/D4RE00278D","url":null,"abstract":"<p >Biomass and bio-derived chemicals can be transformed into ethylene glycol (EG) <em>via</em> catalytic hydrogenation, but a small amount of 2,3-butanediol (23BDO) is generated. 23BDO in EG was removed <em>via</em> the dehydration reaction over H-beta zeolite calcined at 800 °C, with a 23BDO conversion of 80.4% and corresponding SF value of 17.1, which was almost thrice that over the original zeolite due to the suppression of ketalization and oligomerization reactions of EG, especially the latter. The conversions of C<small><sub>3–6</sub></small> diols depended on the numbers of carbon atoms due to a positive effect of the alkyl group on their reactivity, with five-fold SF values compared to the pristine zeolite. The pore and crystal structures of the zeolite were disturbed to a small extent after calcination, resulting in its weakened catalytic activity. The NH<small><sub>3</sub></small>-TPD result proved that the number of acid sites was significantly reduced after calcination, and the ratios of medium and strong acid sites were slightly decreased. The thermal decomposition of Si(OH)Al (Brønsted acid) and EFAL groups (Lewis acid) was confirmed by FTIR. The order of the EG oligomerization reaction with respect to catalyst dosage (third order) was higher than that of the ketalization reaction (first order), so the decrease of the number of acid sites was most unfavorable to EG oligomerization. Compared to the ketalization reaction, the dehydration reaction of 23BDO was less affected after the elimination of EFAL groups, which could not catalyze the dehydration reaction. The used catalyst was regenerated by calcination at 600 °C. The conversions of 23BDO and EG declined to a small and similar degree in the reuse experiment, indicative of the high stability of this modified catalyst.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 5","pages":" 1067-1076"},"PeriodicalIF":3.4,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888487","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":"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}
Haoran Li, Tenghao Ma, Tingting Hao, Jian Hao, Jing Wang, Yabin Wang, Zheng Zhao and Chenyu Lei
{"title":"Pr-doped oxygen-vacancy-induced porous NiMoO4 cathode and MoS2-modified CNT anode for constructing ultra-high-performance supercapacitors","authors":"Haoran Li, Tenghao Ma, Tingting Hao, Jian Hao, Jing Wang, Yabin Wang, Zheng Zhao and Chenyu Lei","doi":"10.1039/D4RE00577E","DOIUrl":"https://doi.org/10.1039/D4RE00577E","url":null,"abstract":"<p >In this study, the sol–gel method was used to prepare NiMoO<small><sub>4</sub></small> electrode materials doped with different concentrations of the rare earth element Pr. The microstructure and phase structure of the samples were thoroughly studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results showed that the prepared materials were porous nanospheres. Due to their porous spherical shape, these structures showed a large specific surface area, providing more surface area for charge storage and release, which helped in increasing the reaction rate of the electrode, thereby improving the energy storage performance of the capacitor. Since the ionic radius of Pr differed from that of the original metal in NiMoO<small><sub>4</sub></small>, the size mismatch could result in the removal of oxygen atoms from the crystal lattice, forming oxygen vacancies. The electronic structure of the material was changed, and the number of active sites increased, which affected the electrochemical properties of the material. The electrochemical performance of the rare earth Pr-doped NiMoO<small><sub>4</sub></small> electrode material (Pr–NiMoO<small><sub>4</sub></small>) was further tested. The experimental results showed that the Pr–NiMoO<small><sub>4</sub></small> electrode exhibited excellent electrochemical performance with 0.7% Pr doping, achieving a specific capacity of 2078 F g<small><sup>−1</sup></small> at a current density of 1 Å g<small><sup>−1</sup></small>. Even at a current density of 5 Å g<small><sup>−1</sup></small> and 10 000 charge and discharge cycles, the material retained 98.8% of its capacitance, showing better electrochemical stability than undoped NiMoO<small><sub>4</sub></small>. An asymmetric supercapacitor was constructed using 0.7% Pr–NiMoO<small><sub>4</sub></small> material (Pr–NiMoO<small><sub>4</sub></small>) as the positive electrode material and MoS<small><sub>2</sub></small>@C as the negative electrode material, showing a high energy density of 73.5 W h kg<small><sup>−1</sup></small>. After 10 000 charge and discharge cycles, the capacitance retention rate of the capacitor could still be maintained at 91.9%. This study successfully proposes an effective strategy for the preparation of rare earth-doped bimetallic oxide electrode materials.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 5","pages":" 1007-1020"},"PeriodicalIF":3.4,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888481","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}
D. A. Svintsitskiy, E. S. Kvasova, T. Yu. Kardash, N. A. Sokovikov, O. A. Stonkus and A. I. Boronin
{"title":"Highly efficient cobalt-modified hopcalite catalysts prepared through crednerite–spinel transformation†","authors":"D. A. Svintsitskiy, E. S. Kvasova, T. Yu. Kardash, N. A. Sokovikov, O. A. Stonkus and A. I. Boronin","doi":"10.1039/D4RE00552J","DOIUrl":"https://doi.org/10.1039/D4RE00552J","url":null,"abstract":"<p >The work presents a study and comparison of the catalytic properties of hopcalite catalysts composed of copper–manganese and copper–cobalt–manganese spinel particles in the low-temperature CO oxidation reaction. The cubic spinel structure was formed immediately under reaction conditions through the transformation of hydrothermally prepared crednerite CuMn(Co)O<small><sub>2</sub></small> particles. Both the initial crednerite-type and the resultant spinel-type particles (Cu, Mn, Co)<small><sub>3</sub></small>O<small><sub>4</sub></small> exhibited a lamellar morphology and a uniform distribution of elements throughout their bulk and surface. It was found that the modification of the copper–manganese oxide with cobalt resulted in increased particle dispersion and a significant distortion of the crednerite crystal lattice. As a result, this modification reduced the temperature required for the crednerite-to-spinel transformation to 250 °C, whereas the unmodified catalyst is transformed after heating to 350–400 °C only. Furthermore, it was demonstrated that during the CO oxidation at room temperature, the modified spinel particles (Cu, Mn, Co)<small><sub>3</sub></small>O<small><sub>4</sub></small> exhibited a specific catalytic activity ∼3.5 times greater than that of the copper–manganese system. This enhancement is associated with the stabilization of a more oxidized surface state for the modified spinel particles, which may involve an increased contribution of Co<small><sup>3+</sup></small> and Mn<small><sup>4+</sup></small> surface species, as well as an enhancement in the overall lattice oxygen mobility.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 5","pages":" 1021-1037"},"PeriodicalIF":3.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888482","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}