Reaction Chemistry & Engineering最新文献

{"title":"An eco-friendly process of high-temperature calcification transformation process for sustainable alumina production from gibbsitic bauxite","authors":"Xin He, Guo-zhi Lv, Song Wang and Ting-an Zhang","doi":"10.1039/D5RE00125K","DOIUrl":"https://doi.org/10.1039/D5RE00125K","url":null,"abstract":"<p >The Bayer process, currently the predominant method for global alumina production, generates substantial quantities of highly alkaline red mud during production. Due to the absence of appropriate, cost-effective, large-scale disposal methods, the majority of red mud is managed through stockpiling, which poses a significant threat to the ecological environment because of its highly alkaline nature. In this study, a high-temperature calcification method based on source interception was employed to treat gibbsitic bauxite with a focus on mineral phase reconstruction. This method not only enabled efficient high-temperature alumina dissolution but also resulted in a new type red mud structure with a very low alkali content. A systematic investigation was carried out on the thermodynamics of the calcification process as well as the influence of process parameters on this transformation. The chemical composition, mineral phase, and microstructure of the bauxite and slag during different stages of the calcification process were analyzed using X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that temperature and the calcium-to-silicon (C/S) molar ratio had a significant impact on the calcification process. Under high-temperature conditions, adding an appropriate amount of calcium oxide promoted alumina dissolution and sodium oxide recovery. The non-isothermal phase transformation and kinetics of the calcification process were examined through HP DSC. With a calcification temperature of 260 °C, a C/S ratio of 2.5, a mother liquor concentration of 240 g L<small>⁻¹</small>, a caustic ratio of 3.1, and a reaction time of 60 min, the dissolution rate of alumina in bauxite reached 88.63%, which is a 10% improvement compared to the low-temperature Bayer process. The content of Na<small>₂</small>O and the aluminum-to-silicon ratio in the calcined slag were 0.71% and 1.42, respectively. The new type red mud, rich in iron oxide and with a low content of Na<small>₂</small>O, can be mixed with an appropriate amount of iron concentrate and binder to produce iron ore pellets. This enables the full utilization of the new red mud and promotes the clean production of alumina.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 9","pages":" 2067-2079"},"PeriodicalIF":3.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144868529","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":"Recent development of non-noble metal catalysts for the oxygen evolution reaction (OER) under different pH","authors":"Weijie Liu and Kai Wang","doi":"10.1039/D5RE00148J","DOIUrl":"https://doi.org/10.1039/D5RE00148J","url":null,"abstract":"<p >With the advent of the new energy revolution, higher demands have been placed on green hydrogen production. The OER, as the anodic reaction in water electrolysis for hydrogen, involves a four-electron transfer process and has a high energy barrier. Therefore, the development of efficient OER catalysts is crucial. Though IrO<small>₂</small> has been widely applied in lab research, its low abundance in the Earth's crust poses significant challenges for large-scale industrial utilization. As a result, numerous studies have been dedicated to developing non-noble metal catalysts to replace IrO<small>₂</small>, and it has been revealed that the pH conditions are crucial for the activity and stability of OER catalysts. Therefore, this review starts from the OER mechanisms under different pH conditions, and discusses the preparation methods, regulation strategies, and performance of non-noble metal catalysts under different pH conditions. It covers a variety of catalysts, including Co-, Ni-, Mn-, NiFe-based materials and high-entropy alloys, and introduces various regulation methods such as doping, defect engineering, morphology control, construction of heterojunction, electronic spin state regulation, and electrolyte engineering. Finally, it comprehensively assesses the application prospects of the catalysts under different pH conditions in conjunction with OER processes and equipment, providing a reference for future catalyst design and regulation engineering for OER technologies.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 8","pages":" 1704-1729"},"PeriodicalIF":3.4,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680937","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":"Chemistry of catalytic cracking of cyclohexene and 1-methylcyclopentene†","authors":"Xueqian Zhang, Jiasong Yan, Shuai Yuan, Shanqing Yu, Qingyu Liu, Xikai Wang and Rui Li","doi":"10.1039/D5RE00033E","DOIUrl":"https://doi.org/10.1039/D5RE00033E","url":null,"abstract":"<p >Whether cycloalkanes undergo six- or five-membered ring-opening reaction pathways remains controversial. In this work, the catalytic cracking reactions of cyclohexene and 1-methylcyclopentene, as model compounds, were investigated in a pulse microreactor. The characteristics of the reactions of the two model compounds were compared in terms of isomerization, cracking, and hydrogen transfer reaction, and the reasons for the differences in their catalytic reactions were analyzed in combination with thermodynamic and molecular simulation calculations. The results have shown that the catalytic cracking product distributions of cyclohexene and 1-methylcyclopentene were similar owing to their easy mutual isomerization; the five-membered ring-opening cracking pathway was more thermodynamically advantageous than that of six-membered ring-opening cracking, and therefore, the yield of the ring-opening cracking product of 1-methylcyclopentene was comparatively higher; the main products of the hydrogen transfer reaction of the two compounds were alkanes and aromatic hydrocarbons. By comparing the product distributions and reaction activation energies, the ring-opening reaction pathways were clarified, and the catalytic cracking reaction networks of cyclohexene and 1-methylcyclopentene were established.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 8","pages":" 1870-1877"},"PeriodicalIF":3.4,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680962","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":"Enhanced thermostability of C2-symmetrical bis(imino)pyridine-iron precatalysts for ethylene polymerisation via a hybrid steric strategy†","authors":"Shuangshuang Liu, Qiuyu Li, Qaiser Mahmood, Zhixin Yu, Yizhou Wang, Ran Zhang, Geng Ren and Wen-Hua Sun","doi":"10.1039/D5RE00168D","DOIUrl":"https://doi.org/10.1039/D5RE00168D","url":null,"abstract":"<p >The poor performance of bis(arylimino)pyridyl iron precatalysts in ethylene polymerisation at high-temperature makes them less attractive as drop-in catalysts for existing ethylene polymerisation technologies. In this study, employing a one-pot template approach, a series of <em>C</em><small>₂</small>-symmetric bis(imino)pyridine-iron precatalysts were prepared from 2,6-diacetylpyridine, ferrous chloride, and aniline derivatives (eight distinct anilines bearing various steric and electronic substituents) and were characterized by FT-IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. These precatalysts showed high catalytic activity at industrially relevant temperatures. <em>In situ</em> activation with either MAO or MMAO, these complexes exhibited high catalytic activities (on the order of 10<small>⁶</small>–10<small>⁷</small> g<small>_PE</small> mol<small>_Fe</small><small>⁻¹</small> h<small>⁻¹</small>) over a wide temperature range (30–100 °C) and produced high-molecular-weight polyethylene (<em>M</em><small>_w</small> up to 433.1 kg mol<small>⁻¹</small>) with unimodal to bimodal molecular weight distributions. The polymerisation activity, polymer molecular weights, and dispersity are significantly dependent on the <em>ortho</em>-substituents of the N-bound phenyl groups. Less sterically hindered substituents favored higher catalytic activities, while more hindered substituents facilitated the formation of higher molecular weight polyethylene. Moreover, these <em>C</em><small>₂</small>-symmetric precatalysts with hybrid steric hindrance exhibited exceptional activity for producing high-molecular-weight polyethylene, outperforming previously reported symmetrical analogues that showed little to no activity. DSC and NMR analyses confirmed a highly linear polyethylene microstructure with predominantly methyl end groups.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 9","pages":" 2030-2042"},"PeriodicalIF":3.1,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144868499","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":"Electrochemical hydrocarboxylation of styrene with CO2 in continuous flow†","authors":"Jonas Mortier, Christian V. Stevens and Thomas S. A. Heugebaert","doi":"10.1039/D5RE00162E","DOIUrl":"https://doi.org/10.1039/D5RE00162E","url":null,"abstract":"<p >This study demonstrates the advantages of an electrochemical continuous flow cell regarding the β-hydrocarboxylation of styrene. An efficient continuous flow method was developed, obtaining high yields of carboxylic acid with a very low residence time, however still maintaining high selectivity.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 7","pages":" 1455-1460"},"PeriodicalIF":3.4,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/re/d5re00162e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144472737","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":"Carbide slag modified into a thermochemical energy storage material via a dual-effect modification method†","authors":"Caiyun Gao, Jie Zhang, Xiangli Liu, Shipeng Chen, Dong Li and Fei Jin","doi":"10.1039/D5RE00110B","DOIUrl":"https://doi.org/10.1039/D5RE00110B","url":null,"abstract":"<p >In this study, a dual-effect modification method for carbide slag modification into a thermochemical energy storage material was proposed. Results showed that the optimally formulated energy storage material CSMn10 contained CaO, Mn<small>₂</small>O<small>₃</small> and CaMnO<small>₃</small> as the main components, which not only inhibited the sintering of calcium oxide grains in the cycling process but also enhanced the alkalinity of the material. These components also promoted the generation of oxygen vacancies, which were favorable for the carbonation reaction. After 20 cycles, the energy storage density of CSMn10 was 1508.23 kJ kg<small>⁻¹</small>, and its average solar absorptivity was as high as 72.99%, which was 7.19 times higher than that of the unmodified calcium carbide slag (CS), significantly enhancing the cycling stability and light-absorbing ability of the material.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 10","pages":" 2252-2263"},"PeriodicalIF":3.1,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121332","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":"A comprehensive numerical analysis of NO generation routes and combustion characteristics with varying strain rates in methane/n-heptane dual fuel flames","authors":"Pengxiang Zhang, Jianfei Xi, Shuang Li, Guoqing Yang, Yunjun Wang, Yinggui Zhou and Jie Cai","doi":"10.1039/D5RE00181A","DOIUrl":"https://doi.org/10.1039/D5RE00181A","url":null,"abstract":"<p >The influence of strain rate on the combustion characteristics and routes of NO formation in methane/<em>n</em>-heptane dual-fuel engines was scrutinized in this research, utilizing a counterflow flame model. The insights gleaned from this study provide valuable theoretical guidance for a more profound comprehension of the NO formation mechanism, thereby facilitating the enhancement and optimization of natural gas–diesel dual-fuel engines. The findings reveal that with an increasing strain rate, the peak flame temperature initially exhibits a slight increase followed by a decrease, while the heat release rate experiences a significant surge. Concurrently, the high-temperature region and the distribution areas of the main species and intermediate products are markedly reduced. The NO emission index undergoes initial fluctuations and then demonstrates a consistent decline with the increment of the strain rate, implying that a higher strain rate is conducive to curtailing NO formation. Relative to the enhancing effect of elevated O radical molar fractions on NO formation, the reduction in flame temperature exerts a more pronounced inhibitory influence on the generation of thermal NO. An elevated strain rate also intensifies the production of CH radicals, which in turn, bolsters the formation of prompt NO. Furthermore, an increase in strain rate accelerates the reaction between HCCO and CH<small>₂</small> radicals with NO, augmenting NO consumption and enhancing the reduction effect of the reburn route on NO. The contributions of the N<small>₂</small>O intermediate route and the NNH intermediate route to NO generation are found to be negligible.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 8","pages":" 1845-1858"},"PeriodicalIF":3.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680928","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":"Catalytic transformation of epoxy resin into dicyclohexane†","authors":"Ganwen Deng, Liang Li, Chenguang Wang, Haiyong Wang and Yuhe Liao","doi":"10.1039/D5RE00105F","DOIUrl":"https://doi.org/10.1039/D5RE00105F","url":null,"abstract":"<p >Although thermosetting epoxy resins are widely used high performance polymers in industry, chemical conversion of waste epoxy resins into high value products is hampered by their robust structure. Herein, we developed heterogeneous catalysts containing a hydroprocessing catalyst and solid acid for the chemical transformation of glycidyl end-capped poly(bisphenol A-<em>co</em>-epichlorohydrin) into hydrocarbons (mainly dicyclohexane). The yield of propane-2,2-diyldicyclohexane reached 83.6% at 220 °C after 10 h under the action of cooperative catalysis between Pd/C and HZSM-5. It was proved that Pd/C initiated the reaction and the acidic zeolite assisted further degradation into small oxygen-containing molecules. For the conversion of oxygenates into hydrocarbons, the hydrogenation of unsaturated molecules was achieved using Pd/C, and the acidic zeolite dehydrated the hydrogenation products to remove oxygen. Moreover, the anhydride-cured epoxy resin was converted into propane-2,2-diyldicyclohexane in the presence of Pd/C and HZSM-5 after methanolysis. This work demonstrates that the chemical transformation of waste epoxy resin <em>via</em> heterogeneous catalysis is achievable.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 8","pages":" 1859-1869"},"PeriodicalIF":3.4,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680961","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":"Direct aminolysis of methyl esters with ammonia in continuous flow through Bayesian optimization†","authors":"Bavo Vandekerckhove, Stefan Desimpel, Bart Ruttens, Massimo Bocus, Wim Temmerman, Bert Metten, Veronique Van Speybroeck, Thomas S. A. Heugebaert and Christian V. Stevens","doi":"10.1039/D5RE00163C","DOIUrl":"https://doi.org/10.1039/D5RE00163C","url":null,"abstract":"<p >Amides play a crucial role in the pharmaceutical, animal health and agrochemical industry. Despite the availability of various catalytic systems and coupling reagents, many methods suffered from long reaction times and poor atom economy. The direct synthesis of primary amides remained particularly challenging due to the limited availability of suitable nitrogen sources. In this study, continuous flow technology was explored as a process-intensification approach for the direct amidation of methyl esters to produce primary amides. Methanolic ammonia was employed as a nitrogen source to enhance process efficiency while circumventing the limitations of aqueous ammonia and the hazards of gaseous ammonia. Seventeen substrates were screened to assess their aminolysis reactivity under these conditions. As a proof of concept, methyl picolinate was selected for continuous flow optimization using Bayesian optimization. Therefore, a custom-designed high-pressure, high-temperature continuous flow reactor was utilized to achieve efficient, safe and scalable synthesis (200 °C, 50 bar).</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 8","pages":" 1887-1896"},"PeriodicalIF":3.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/re/d5re00163c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680964","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":"Selective transfer hydrogenation of furfural under continuous flow conditions promoted by the recoverable homogeneous Shvo's catalyst†","authors":"Giulia Brufani, Maitê Campos, Chiara Lenzi, Luís Adriano Santos do Nascimento, Emilia Paone, Andrea Piazzi, Rita Mazzoni, Luigi Vaccaro and Francesco Mauriello","doi":"10.1039/D5RE00176E","DOIUrl":"https://doi.org/10.1039/D5RE00176E","url":null,"abstract":"<p >The continuous-flow application of the homogeneous Shvo's catalyst for the selective transfer hydrogenation of furfural to furfuryl alcohol, utilizing biobased 2-methyltetrahydrofuran as the reaction medium and 2-propanol as a stoichiometric hydrogen donor is reported for the first time. The homogeneous catalyst demonstrated excellent recyclability, maintaining high performance over at least five consecutive reaction cycles. This process represents an efficient and waste-minimized strategy for the reductive catalytic valorization of biomass-derived furfural under continuous-flow conditions, as validated by a comprehensive green metrics assessment.</p>","PeriodicalId":101,"journal":{"name":"Reaction Chemistry & Engineering","volume":" 6","pages":" 1227-1232"},"PeriodicalIF":3.4,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/re/d5re00176e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148236","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}