ACS Engineering Au最新文献

{"title":"Correction to “Model-Based Scale-Up of a Homogeneously Catalyzed Sonogashira Coupling Reaction in a 3D Printed Continuous-Flow Reactor”","authors":"Lisa Schulz, Norbert Kockmann and Thorsten Röder*, ","doi":"10.1021/acsengineeringau.5c0000610.1021/acsengineeringau.5c00006","DOIUrl":"https://doi.org/10.1021/acsengineeringau.5c00006https://doi.org/10.1021/acsengineeringau.5c00006","url":null,"abstract":"","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"66 66"},"PeriodicalIF":4.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.5c00006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operating Ranges of Coupled–Decoupled Counter-current Downer and Riser Reactors","authors":"Mengmeng Cui,&nbsp;Lujain Alfilfil,&nbsp;Isidoro Morales Osorio,&nbsp;Khalid Almajnouni,&nbsp;Jorge Gascon and Pedro Castaño*,&nbsp;","doi":"10.1021/acsengineeringau.4c0004110.1021/acsengineeringau.4c00041","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00041https://doi.org/10.1021/acsengineeringau.4c00041","url":null,"abstract":"<p >The counter-current downers have the potential to combine the hydrodynamic characteristics of co-current risers and downers with less back-mixing and improved solid holdup. However, flooding may occur when particles suspend or reverse the flowing direction under increasing superficial gas velocity or solid mass flux. Here, we evaluate transported bed configurations by coupling the counter-current downer with a riser reactor to take advantage of the flooding behaviors. We analyze the theoretical hydrodynamics in risers and co- and counter-current downers from particle mechanics to cluster development. By validation with experimental results from the literature, we determine the proper simulation strategy for counter-current downers using computational particle fluid dynamics by replacing the particle size with empirically calculated cluster size. We investigate the effects of superficial gas velocity and solid mass flux with Geldart group A particles until beyond the flooding point of the counter-current downer. The coupled riser–counter-current downer reactor configuration offers more uniform axial and dynamic radial solid distribution while keeping a relatively high solid holdup to better utilize the reactor volume for enhanced gas–solid contact. The fluidization regime diagram by the Richardson–Zaki equation fails to capture the counter-current operation, so we provide a separate graph to mark the limitation of the coupled and decoupled riser and counter-current downer reactor configurations.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"45–56 45–56"},"PeriodicalIF":4.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Mass Transfer Phenomena in Electrochemical Nitrate Reduction: A Case Study Using Ti and Ag-Modified Ti-Hollow Fiber Electrodes","authors":"Ainoa Paradelo Rodríguez,&nbsp;Guido Mul* and Bastian T. Mei*,&nbsp;","doi":"10.1021/acsengineeringau.4c0003510.1021/acsengineeringau.4c00035","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00035https://doi.org/10.1021/acsengineeringau.4c00035","url":null,"abstract":"<p >Decentralized electrochemical reduction of nitrate into ammonium is explored as a viable approach to mitigate nitrate accumulation in groundwater. In this study, tubular porous electrodes made of titanium (termed hollow fiber electrodes or HFEs) were successfully modified with silver (Ag) nanoparticles through electrodeposition. Under galvanostatic control and in acidic electrolyte, Ag deposition on Ti HFE resulted in an increase in the Faradaic efficiency for ammonium formation from low concentrations of nitrate (50 mM), but only under reaction conditions of restricted mass transport. For conditions of favorable transport, facilitated by an inert gas flow (Ar) exiting the pores, a higher nitrate conversion but an increase in hydroxylamine selectivity at the expense of the ammonium selectivity are observed for Ti/Ag hollow fiber electrodes. For Ti/Ag electrodes, it is concluded that ammonium formation is prevented by effective removal of surface intermediates. Remarkably, for unmodified Ti hollow fiber electrodes, the Faradaic efficiency to ammonium is significantly improved when operated at high current densities and in conditions of high mass transport. The selectivity to liquid products even surpasses the selectivity of Ti/Ag electrodes. These findings indicate that nitrate reduction to ammonium at Ti and Ti/Ag hollow fiber electrodes can be achieved at comparable rates but under distinctly different process conditions. In fact, for Ti electrodes, operation at a lower applied potential compared to Ti/Ag electrodes is feasible, ultimately resulting in reduced energy consumption. This study thus highlights the importance of controlling the interfacial electrode environment, particularly when comparing and evaluating the effectiveness of electrode materials in electrochemical nitrate reduction. The study also reveals that transport phenomena affect electrode material-dependent activity–selectivity correlations and must be considered in ongoing material development efforts.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"27–35 27–35"},"PeriodicalIF":4.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Mass Transfer Phenomena in Electrochemical Nitrate Reduction: A Case Study Using Ti and Ag-Modified Ti-Hollow Fiber Electrodes.","authors":"Ainoa Paradelo Rodríguez, Guido Mul, Bastian T Mei","doi":"10.1021/acsengineeringau.4c00035","DOIUrl":"10.1021/acsengineeringau.4c00035","url":null,"abstract":"<p><p>Decentralized electrochemical reduction of nitrate into ammonium is explored as a viable approach to mitigate nitrate accumulation in groundwater. In this study, tubular porous electrodes made of titanium (termed hollow fiber electrodes or HFEs) were successfully modified with silver (Ag) nanoparticles through electrodeposition. Under galvanostatic control and in acidic electrolyte, Ag deposition on Ti HFE resulted in an increase in the Faradaic efficiency for ammonium formation from low concentrations of nitrate (50 mM), but only under reaction conditions of restricted mass transport. For conditions of favorable transport, facilitated by an inert gas flow (Ar) exiting the pores, a higher nitrate conversion but an increase in hydroxylamine selectivity at the expense of the ammonium selectivity are observed for Ti/Ag hollow fiber electrodes. For Ti/Ag electrodes, it is concluded that ammonium formation is prevented by effective removal of surface intermediates. Remarkably, for unmodified Ti hollow fiber electrodes, the Faradaic efficiency to ammonium is significantly improved when operated at high current densities and in conditions of high mass transport. The selectivity to liquid products even surpasses the selectivity of Ti/Ag electrodes. These findings indicate that nitrate reduction to ammonium at Ti and Ti/Ag hollow fiber electrodes can be achieved at comparable rates but under distinctly different process conditions. In fact, for Ti electrodes, operation at a lower applied potential compared to Ti/Ag electrodes is feasible, ultimately resulting in reduced energy consumption. This study thus highlights the importance of controlling the interfacial electrode environment, particularly when comparing and evaluating the effectiveness of electrode materials in electrochemical nitrate reduction. The study also reveals that transport phenomena affect electrode material-dependent activity-selectivity correlations and must be considered in ongoing material development efforts.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"27-35"},"PeriodicalIF":4.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11843601/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143484086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafine Particle Recycling─Efficiency of the Hydrophobic Double Emulsion Technique for the Selective Agglomeration and Froth Flotation of Ultrafine Cathode Catalyst Particles from PEM Water Electrolyzers","authors":"Sohyun Ahn*,&nbsp;Suvarna Patil and Martin Rudolph,&nbsp;","doi":"10.1021/acsengineeringau.4c0004210.1021/acsengineeringau.4c00042","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00042https://doi.org/10.1021/acsengineeringau.4c00042","url":null,"abstract":"<p >On account of the use of platinum group metals (PGMs) as active materials in proton exchange membrane water electrolyzer (PEMEL) cells, development of recycling processes for fine catalyst materials is indispensable for further scale-up of hydrogen production. By applying a contrast in (de)wetting ability of the materials, ultrafine particles have the potential to be separated for recycling. The limitation of particle size in froth flotation technology can be overcome by adding oil droplets to the system. This study investigates the selective separation of ultrafine particles by applying hydrophobic high internal phase (HIP) water-in-oil emulsion containing only 5% of organic liquid emulsified as a double emulsion in the particle dispersion. Hydrophobic cathode particles (i.e., carbon black) are selectively agglomerated in this system, allowing 90% of the feed to be recovered in the froth phase. The recovery rate was also significantly higher than that using the same amount of pure oil promoter, kerosene. In the binary particle system, 70% of the target particles are recovered with 90% grade by adding 2.8% hydrophobic double emulsion.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"57–65 57–65"},"PeriodicalIF":4.3,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ACS Engineering Au’s Special Issue on “Insights, Innovations, and Intensification” 2024","authors":"Vivek V. Ranade*,&nbsp; and ,&nbsp;Linda J. Broadbelt*,&nbsp;","doi":"10.1021/acsengineeringau.4c0005010.1021/acsengineeringau.4c00050","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00050https://doi.org/10.1021/acsengineeringau.4c00050","url":null,"abstract":"","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"4 6","pages":"491–492 491–492"},"PeriodicalIF":4.3,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142842542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistic Insights into Paracetamol Crystallization: Exploring Ultrasound and Hydrodynamic Cavitation with Quartz Crystal Microbalance Dissipation","authors":"Madhumitha Dhanasekaran*,&nbsp;Varaha P. Sarvothaman*,&nbsp;Paolo Guida and William L. Roberts,&nbsp;","doi":"10.1021/acsengineeringau.4c0003610.1021/acsengineeringau.4c00036","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00036https://doi.org/10.1021/acsengineeringau.4c00036","url":null,"abstract":"<p >Crystallization is a crucial process in the purification of active pharmaceutical ingredients (APIs). Achieving controlled and efficient crystal formation is vital in successful production for industrial applications. This study investigates the crystallization of paracetamol using a model system, focusing on two techniques: ultrasound cavitation (UC) and hydrodynamic cavitation (HC). The role of cavitation in enhancing crystallization is well-established by using ultrasound. However, the crystallization process utilizing HC, especially in the absence of an antisolvent, is not investigated. A detailed investigation is still necessary to understand the nucleation process at the molecular level. This work primarily focuses on forming paracetamol crystals in an aqueous medium without the need for an antisolvent in HC. To address the nucleation study at the molecular level, the quartz crystal microbalance with dissipation (QCM-D) technique was employed to explore the nucleation kinetics of paracetamol crystallization while the solution is cooling. QCM-D allowed for real-time monitoring of mass changes and viscoelastic properties on the sensor surface, providing valuable insights into the adsorption, growth, and dissolution kinetics of paracetamol crystals under the influence of both cavitation techniques. The study revealed distinct crystallization behaviors depending on the type and intensity of cavitation, shedding light on the underlying mechanisms and potential implications for pharmaceutical manufacturing and formulation. These findings indicate that high-quality crystals can be produced using HC without the need for an antisolvent. This work highlights the significant potential for improving the efficiency and control of paracetamol crystallization and plays an important role in scaling up the crystallization process using HC.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"36–44 36–44"},"PeriodicalIF":4.3,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model-Based Scale-Up of a Homogeneously Catalyzed Sonogashira Coupling Reaction in a 3D Printed Continuous-Flow Reactor","authors":"Lisa Schulz,&nbsp;Norbert Kockmann and Thorsten Röder*,&nbsp;","doi":"10.1021/acsengineeringau.4c0002710.1021/acsengineeringau.4c00027","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00027https://doi.org/10.1021/acsengineeringau.4c00027","url":null,"abstract":"<p >The model-based scale-up of a homogeneously catalyzed Sonogashira coupling reaction is performed in a 3D printed metal continuous-flow reactor. The reaction is monitored with inline Raman spectroscopy with a low calibration effort, applying a multivariate curve resolution approach. Manufacturing conditions result in a space time yield of 412 kg m^–3 h^–1 and a productivity rate of 0.078 kg h^–1.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"4 6","pages":"519–523 519–523"},"PeriodicalIF":4.3,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strategies for the Design and Synthesis of Pt-Based Nanostructured Electrocatalysts in Proton Exchange Membrane Fuel Cells (PEMFCs)","authors":"Jae-Hun Kim,&nbsp;Soo Youn Lee,&nbsp;Hye Jin Lee,&nbsp;Hae In Lee,&nbsp;Dong-Ha Lim,&nbsp;Yoo Seok Lee*,&nbsp;Hee Soo Kim* and Sahng Hyuck Woo*,&nbsp;","doi":"10.1021/acsengineeringau.4c0003210.1021/acsengineeringau.4c00032","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00032https://doi.org/10.1021/acsengineeringau.4c00032","url":null,"abstract":"<p >With the rapidly increasing use of fossil fuels, the exploration of various renewable energy sources has become critical. Among these, proton exchange membrane fuel cells (PEMFCs) are garnering significant attention as the next generation of green energy, which is ascribed to their ability to directly convert chemical energy into electricity without emitting pollutants. Specifically, the design and synthesis of effective catalysts are crucial in reducing the cost of commercial PEMFCs because the performance of the oxygen reduction reaction (ORR), which is the most critical reaction in PEMFCs, dictates the overall performance of the cell. Consequently, numerous research groups have recently focused on enhancing the performance and durability of the ORR catalysts. These improvements are being pursued in various fields, including geometry engineering and interfacial engineering. Efforts involve tuning the size and chemical composition of Pt catalysts, as well as developing diverse nanostructures that can be selectively positioned on the crystal surface or alloyed with transition metals. This review delves into the fundamentals of fuel cells and ORR catalysts, which are pivotal energy sources in the realm of green energy. It also outlines a series of catalyst synthesis strategies aimed at boosting their performance. Additionally, this paper offers new insights and highlights key considerations for the future development of platinum-based ORR catalysts in fuel cells.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"1–9 1–9"},"PeriodicalIF":4.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Potassium Addition on the Performance of Ni/MgAl2O4 Catalysts in Steam Reforming of Bio-Oil Model Compounds","authors":"Alan R. Taschin,&nbsp;Davi D. Petrolini,&nbsp;Adriano H. Braga,&nbsp;Alexandre Baiotto,&nbsp;Adriana Paula Ferreira,&nbsp;Alejandro Lopez-Castillo,&nbsp;João Batista O. Santos and José M. C. Bueno*,&nbsp;","doi":"10.1021/acsengineeringau.4c0003410.1021/acsengineeringau.4c00034","DOIUrl":"https://doi.org/10.1021/acsengineeringau.4c00034https://doi.org/10.1021/acsengineeringau.4c00034","url":null,"abstract":"<p >Ni/MgAl₂O₄ catalysts with and without K promotion were tested in steam reforming of phenol (SRP), ethanol (SRE), and butanol (SRB), to evaluate the effect of K on catalytic activity and methane formation. The catalysts were prepared by a wet impregnation method and were characterized using nitrogen adsorption, in situ XRD, H₂-TPR, TEM, XPS, and XANES techniques. Catalytic evaluations were performed at temperatures ranging from 250 to 650 °C. DFT calculations were employed to study the hydrogenation of CH_<i>x</i> species on Ni modified by K. The addition of K to the Ni catalysts weakened the NiO-support interaction, causing NiO agglomeration and an increase in Ni particle size. The effect of K on CH₄ formation was strongly influenced by the structure of the reformed molecule, leading to the formation of different CH_<i>x</i> species during the reaction. The introduction of K into the Ni catalyst suppressed formation of CH₄ by hydrogenation of CH, with this effect diminishing for CH₂ and being absent for CH₃ species. DFT calculations of the interaction between CH_<i>x</i> species absorbed in an Ni₄ cluster (CH_<i>x</i>-Ni₄) and K, particularly KOH, indicated that species such as HOKH_<i>x</i>C–Ni₄ were stabilized, with decreased energies of −291.5, −242.4, and −27.7 kJ/mol for CH, CH₂, and CH₃, respectively. The increased heat of adsorption for CH and CH₂ species reduced their hydrogenation activity toward methane.</p>","PeriodicalId":29804,"journal":{"name":"ACS Engineering Au","volume":"5 1","pages":"10–26 10–26"},"PeriodicalIF":4.3,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsengineeringau.4c00034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}