Pub Date : 2025-02-15DOI: 10.1016/j.ces.2025.121376
Ya Gao , Jing Zhang , Yirong Wang , Qingtao Jiang , Xingli Zou , Xionggang Lu , Mohd Ubaidullah , Reinaldo F. Teófilo , Yufeng Zhao
Investigations on high-efficiency single atom catalysts (SACs) for oxygen reduction reaction (ORR) have aroused widespread concern, particularly for transition metals. However, the inherent catalytic performance is greatly affected by metal types and pore structure of carbon substrates. Herein, a non-noble Zn-based single-atom electrocatalyst (Zn-N-C) is proposed and confirmed that atomically dispersed Zn is anchored onto the amply micro/mesoporous support decorated with nitrogen doping. Benefit from the pore structure and single-atom site, Zn-N-C reveals superior ORR behavior with high E1/2 (0.874 V) and low Tafel slope (68.8 mV dec-1) in 0.1 M KOH, markedly surpassing state-of-the-art Pt/C. EXAFS and DFT results show that Zn-N4 coordination configuration decreases the free energies of oxygen-containing intermediates (*OOH and *OH) and the theoretical overpotential is as low as 0.45 eV. As a result, the self-assembled Zn-air battery performs well in peak power density (226.4 mW cm−2), specific capacity (746.4 mAh g−1) and long-term durability.
{"title":"Single Zn atoms and hierarchical pore architecture jointly improve oxygen reduction electrocatalysis","authors":"Ya Gao , Jing Zhang , Yirong Wang , Qingtao Jiang , Xingli Zou , Xionggang Lu , Mohd Ubaidullah , Reinaldo F. Teófilo , Yufeng Zhao","doi":"10.1016/j.ces.2025.121376","DOIUrl":"10.1016/j.ces.2025.121376","url":null,"abstract":"<div><div>Investigations on high-efficiency single atom catalysts (SACs) for oxygen reduction reaction (ORR) have aroused widespread concern, particularly for transition metals. However, the inherent catalytic performance is greatly affected by metal types and pore structure of carbon substrates. Herein, a non-noble Zn-based single-atom electrocatalyst (Zn-N-C) is proposed and confirmed that atomically dispersed Zn is anchored onto the amply micro/mesoporous support decorated with nitrogen doping. Benefit from the pore structure and single-atom site, Zn-N-C reveals superior ORR behavior with high <em>E<sub>1/2</sub></em> (0.874 V) and low Tafel slope (68.8 mV dec<sup>-1</sup>) in 0.1 M KOH, markedly surpassing state-of-the-art Pt/C. EXAFS and DFT results show that Zn-N<sub>4</sub> coordination configuration decreases the free energies of oxygen-containing intermediates (*OOH and *OH) and the theoretical overpotential is as low as 0.45 eV. As a result, the self-assembled Zn-air battery performs well in peak power density (226.4 mW cm<sup>−2</sup>), specific capacity (746.4 mAh g<sup>−1</sup>) and long-term durability.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121376"},"PeriodicalIF":4.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.ces.2025.121363
Mohamed S. Mohamed , Brian P. Chaplin , Ahmed A. Abokifa
Transition metals are promising candidates for catalytic destruction of per- and polyfluoroalkyl substances (PFAS). This study employed density functional theory (DFT) calculations to systematically investigate the adsorption of PFAS, which is a critical step in the catalytic process, onto a group of transition metals, namely Cu, Pd, Pt, and Rh. The investigation considered the influence of different PFAS characteristics, including chain length, functional group (i.e., sulfonic vs. carboxylic), and protonation state (i.e., protonated, anionic, and deprotonated radical) on the adsorption mechanism. Overall, the findings indicated that the adsorption of PFAS on transition metals exhibited thermodynamically favorable energetics, with Rh showing the most favorable adsorption for PFAS. However, the adsorption strength was significantly dependent on the protonation state of PFAS. Cu was the highest electron donor, while Pt was the highest electron acceptor. Results were compared to experimental studies in the literature for qualitative validation.
{"title":"Screening of transition metals for PFAS adsorption: A comparative DFT investigation","authors":"Mohamed S. Mohamed , Brian P. Chaplin , Ahmed A. Abokifa","doi":"10.1016/j.ces.2025.121363","DOIUrl":"10.1016/j.ces.2025.121363","url":null,"abstract":"<div><div>Transition metals are promising candidates for catalytic destruction of per- and polyfluoroalkyl substances (PFAS). This study employed density functional theory (DFT) calculations to systematically investigate the adsorption of PFAS, which is a critical step in the catalytic process, onto a group of transition metals, namely Cu, Pd, Pt, and Rh. The investigation considered the influence of different PFAS characteristics, including chain length, functional group (i.e., sulfonic vs. carboxylic), and protonation state (i.e., protonated, anionic, and deprotonated radical) on the adsorption mechanism. Overall, the findings indicated that the adsorption of PFAS on transition metals exhibited thermodynamically favorable energetics, with Rh showing the most favorable adsorption for PFAS. However, the adsorption strength was significantly dependent on the protonation state of PFAS. Cu was the highest electron donor, while Pt was the highest electron acceptor. Results were compared to experimental studies in the literature for qualitative validation.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121363"},"PeriodicalIF":4.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.ces.2025.121371
Yao Miao, Zhiling Qian, Hongliang Cao, Ying Yang, Ping Li
An advanced multicolumn vacuum pressure swing adsorption process (namely as the VPSA-SMB process) is developed to simultaneously recover high-purity methane and high-purity carbon dioxide from biogas feedstock, using commercial ZSM-5 zeolite as the adsorbent. In this novel process, the tandem multicolumn is adopted at the pressurization, adsorption and displacement steps to improve CH4/CO2 separation; one tower filled with high-purity CO2 will go on the blowdown/purge steps for the regeneration of adsorbents; the cyclic operation is executed automatically with the simulated moving bed mode, shifting the inlet/outlet ports of gas streams one by one tower. In the laboratory, a six-tower VPSA-SMB unit packed with ZSM-5 zeolites was constructed, and the mathematical model appliable to predict the CH4/CO2 separation performance of the novel process was built. Through experiments and simulations, it is proved to be technically feasible and highly efficient for biomethane production with a purity >96 % and recovery >99 % while achieving CO2-purity >99 % from the wide CH4 content biogas using the novel adsorption process. Additionally, the selection of feed gas and replacement gas flow rates to improve CH4/CO2 separation, as well as the choice of switching time for the inlet and outlet ports of gases were discussed.
{"title":"Modelling and experiment for simultaneous biogas upgrading and CO2 capture by an advanced VPSA-SMB process","authors":"Yao Miao, Zhiling Qian, Hongliang Cao, Ying Yang, Ping Li","doi":"10.1016/j.ces.2025.121371","DOIUrl":"10.1016/j.ces.2025.121371","url":null,"abstract":"<div><div>An advanced multicolumn vacuum pressure swing adsorption process (namely as the VPSA-SMB process) is developed to simultaneously recover high-purity methane and high-purity carbon dioxide from biogas feedstock, using commercial ZSM-5 zeolite as the adsorbent. In this novel process, the tandem multicolumn is adopted at the pressurization, adsorption and displacement steps to improve CH<sub>4</sub>/CO<sub>2</sub> separation; one tower filled with high-purity CO<sub>2</sub> will go on the blowdown/purge steps for the regeneration of adsorbents; the cyclic operation is executed automatically with the simulated moving bed mode, shifting the inlet/outlet ports of gas streams one by one tower. In the laboratory, a six-tower VPSA-SMB unit packed with ZSM-5 zeolites was constructed, and the mathematical model appliable to predict the CH<sub>4</sub>/CO<sub>2</sub> separation performance of the novel process was built. Through experiments and simulations, it is proved to be technically feasible and highly efficient for biomethane production with a purity >96 % and recovery >99 % while achieving CO<sub>2</sub>-purity >99 % from the wide CH<sub>4</sub> content biogas using the novel adsorption process. Additionally, the selection of feed gas and replacement gas flow rates to improve CH<sub>4</sub>/CO<sub>2</sub> separation, as well as the choice of switching time for the inlet and outlet ports of gases were discussed.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121371"},"PeriodicalIF":4.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fisher’s esterification has been one of the most studied reactions in organic chemistry for esters production. This type of reaction commonly has the disadvantage of being very slow, thus, several alternative methods to accelerate them have been studied. In this work, the reaction between cyanoacetic acid and n-butanol catalyzed with p-toluensulfonic acid has been the objective. The effects of the reactants and the temperature on the reaction rate were studied under different thermal conditions. In addition, the effect of ultrasonic waves on the reaction was also considered. Compared to conventional heating method, the latter favored the reaction rate, being constant up to a certain temperature, after which the cavitation phenomenon does not occur, and the reaction slows down. Finally, using this methodology, no other products or collateral reactions were detected, meaning that the application of ultrasonic waves can be effective in increasing the industrial production of n-butylcyanoacetate.
{"title":"Synthesis of n-butylcyanoacetate by ultrasonic waves. Kinetic comparison with thermal conditions","authors":"Yuliet Paez-Amieva , Katia Borrego-Morales , Rubén Álvarez-Brito , Alen Nils Baeza-Fonte","doi":"10.1016/j.ces.2025.121372","DOIUrl":"10.1016/j.ces.2025.121372","url":null,"abstract":"<div><div>Fisher’s esterification has been one of the most studied reactions in organic chemistry for esters production. This type of reaction commonly has the disadvantage of being very slow, thus, several alternative methods to accelerate them have been studied. In this work, the reaction between cyanoacetic acid and n-butanol catalyzed with p-toluensulfonic acid has been the objective. The effects of the reactants and the temperature on the reaction rate were studied under different thermal conditions. In addition, the effect of ultrasonic waves on the reaction was also considered. Compared to conventional heating method, the latter favored the reaction rate, being constant up to a certain temperature, after which the cavitation phenomenon does not occur, and the reaction slows down. Finally, using this methodology, no other products or collateral reactions were detected, meaning that the application of ultrasonic waves can be effective in increasing the industrial production of n-butylcyanoacetate.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121372"},"PeriodicalIF":4.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.ces.2025.121374
Huaiyu Li , Xiangwen Zhang , Kang Xue , Chongjun Li , Xinkai Jin , Xiaoyang Liu , Minhua Ai , Chengxiang Shi , Ji-Jun Zou , Lun Pan
The ignition difficulty and low combustion efficiency of boron seriously hinder its practical application. Herein, we prepared the fluoroalkylsilane-functionalized microcapsules (nB@CS-xF) by encapsulating nano-boron particles (nBs) in chitosan modified by 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, using the controlled droplet microfluidic technique. The functionalized microcapsules enable the coupling of F-mediated pre-ignition reaction and micro-explosion during combustion, reducing the initial exothermic peak temperature (Tp1) of boron, eliminating the surface oxidation layer, and dispersing the particles to prevent agglomeration, which significantly improves the combustion efficiency of nBs. Specifically, the Tp1 of nB@CS-12F (452.5 °C) is lower than that of nBs (600.9 °C), and its combustion heat and peak pressure increased by 103.6 % and 43.7 % compared with nBs, respectively. Finally, the combustion mechanism of nB@CS-xF is proposed by combining in situ spectroscopy of the combustion process and combustion product analysis. This work provides a new pathway for improving the performance of energetic particles.
{"title":"Fluoroalkyl functionalization of boron-based microcapsules via microfluidics for superior ignition and combustion performances","authors":"Huaiyu Li , Xiangwen Zhang , Kang Xue , Chongjun Li , Xinkai Jin , Xiaoyang Liu , Minhua Ai , Chengxiang Shi , Ji-Jun Zou , Lun Pan","doi":"10.1016/j.ces.2025.121374","DOIUrl":"10.1016/j.ces.2025.121374","url":null,"abstract":"<div><div>The ignition difficulty and low combustion efficiency of boron seriously hinder its practical application. Herein, we prepared the fluoroalkylsilane-functionalized microcapsules (nB@CS-<em>x</em>F) by encapsulating nano-boron particles (nBs) in chitosan modified by 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, using the controlled droplet microfluidic technique. The functionalized microcapsules enable the coupling of F-mediated pre-ignition reaction and micro-explosion during combustion, reducing the initial exothermic peak temperature (<em>T</em><sub>p1</sub>) of boron, eliminating the surface oxidation layer, and dispersing the particles to prevent agglomeration, which significantly improves the combustion efficiency of nBs. Specifically, the <em>T</em><sub>p1</sub> of nB@CS-12F (452.5 °C) is lower than that of nBs (600.9 °C), and its combustion heat and peak pressure increased by 103.6 % and 43.7 % compared with nBs, respectively. Finally, the combustion mechanism of nB@CS-<em>x</em>F is proposed by combining <em>in situ</em> spectroscopy of the combustion process and combustion product analysis. This work provides a new pathway for improving the performance of energetic particles.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121374"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.ces.2025.121364
Weili Feng , Xiaoming Sun , Siyi Zhang , Feng Shi , Pinhua Rao , Jinguo Wang , Jiang Wu
The chemical adsorption of elemental mercury (Hg0) from SO2-rich flue gas is an effective method for preventing heavy metal pollution. Among the metal sulfide sorbents, CuS has demonstrated excellent Hg0 immobilization performance. In this study, hierarchical flower-like CuS structures were synthesized by controlling the hydrothermal nucleation temperature. CuS(flower)-120 exhibited an exceptional Hg0 removal efficiency, achieving nearly 100 % removal. Furthermore, the Hg0 removal efficiency remained at 100 % across a temperature range from 25 °C to 120 °C. Despite the negative effects of both O2 and SO2 on Hg0 capture, the removal efficiency remained at 97 % under 5,000 ppm SO2 and 3 % O2. The kinetic data indicated that CuS(flower)-120 possessed a high adsorption capacity of up to 9.37 mg/g with only 20 % breakthrough point; the equilibrium adsorption capacity is 33.21 mg/g and the initial adsorption rate is as high as 12.92 μg/(g(CuS)·min). The results of X-ray photoelectron spectroscopy (XPS) combined with density functional theory (DFT) and mercury temperature-programmed desorption (Hg-TPD) revealed that the Cu-Hg amalgam could further interact with Sn2− or S22− to form HgS, eventually leading to the formation of β-HgS and α-HgS. The results we report here provide a practical and straightforward strategy for mercury pollution control while also opening new avenues for resource utilization of toxic elements.
{"title":"Self-assembled nano-size flower CuS for elemental mercury immobilization in SO2-rich flue gas","authors":"Weili Feng , Xiaoming Sun , Siyi Zhang , Feng Shi , Pinhua Rao , Jinguo Wang , Jiang Wu","doi":"10.1016/j.ces.2025.121364","DOIUrl":"10.1016/j.ces.2025.121364","url":null,"abstract":"<div><div>The chemical adsorption of elemental mercury (Hg<sup>0</sup>) from SO<sub>2</sub>-rich flue gas is an effective method for preventing heavy metal pollution. Among the metal sulfide sorbents, CuS has demonstrated excellent Hg<sup>0</sup> immobilization performance. In this study, hierarchical flower-like CuS structures were synthesized by controlling the hydrothermal nucleation temperature. CuS(flower)-<sub>120</sub> exhibited an exceptional Hg<sup>0</sup> removal efficiency, achieving nearly 100 % removal. Furthermore, the Hg<sup>0</sup> removal efficiency remained at 100 % across a temperature range from 25 °C to 120 °C. Despite the negative effects of both O<sub>2</sub> and SO<sub>2</sub> on Hg<sup>0</sup> capture, the removal efficiency remained at 97 % under 5,000 ppm SO<sub>2</sub> and 3 % O<sub>2</sub>. The kinetic data indicated that CuS(flower)-<sub>120</sub> possessed a high adsorption capacity of up to 9.37 mg/g with only 20 % breakthrough point; the equilibrium adsorption capacity is 33.21 mg/g and the initial adsorption rate is as high as 12.92 μg/(g<sub>(CuS)</sub>·min). The results of X-ray photoelectron spectroscopy (XPS) combined with density functional theory (DFT) and mercury temperature-programmed desorption (Hg-TPD) revealed that the Cu-Hg amalgam could further interact with S<sub>n</sub><sup>2−</sup> or S<sub>2</sub><sup>2−</sup> to form HgS, eventually leading to the formation of β-HgS and α-HgS. The results we report here provide a practical and straightforward strategy for mercury pollution control while also opening new avenues for resource utilization of toxic elements.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121364"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.ces.2025.121369
Wensheng Wang , Mingxin Li , Tingliang Xie , Cong Xu
Immiscible two-phase droplet flow in microchannels serves as a widely utilized platform for various applications, including solvent extraction, material synthesis, and chemical reactions. However, achieving rapid phase separation at high throughput remains a challenge. This study presents an electro-microfluidic phase separator that integrates an insulated alternating current electric field with a flat microchannel to facilitate droplet coalescence and phase separation. Two primary mechanisms of phase separation are identified: droplet-to-droplet coalescence and droplet-to-layer coalescence. The YOLOv5 deep learning algorithm is employed to identify droplets and evaluate their sizes. A robust phase separator has been developed, demonstrating the capability to achieve rapid phase separation with a throughput of up to 200 mL/min. Furthermore, the study examines the effects of electrolyte concentration, phase ratio, flow rate, and the voltage and frequency of the electric field on phase separation. The synergistic effect of the design in enhancing phase separation at high throughput is confirmed.
{"title":"High-throughput electro-microfluidic phase separator","authors":"Wensheng Wang , Mingxin Li , Tingliang Xie , Cong Xu","doi":"10.1016/j.ces.2025.121369","DOIUrl":"10.1016/j.ces.2025.121369","url":null,"abstract":"<div><div>Immiscible two-phase droplet flow in microchannels serves as a widely utilized platform for various applications, including solvent extraction, material synthesis, and chemical reactions. However, achieving rapid phase separation at high throughput remains a challenge. This study presents an electro-microfluidic phase separator that integrates an insulated alternating current electric field with a flat microchannel to facilitate droplet coalescence and phase separation. Two primary mechanisms of phase separation are identified: droplet-to-droplet coalescence and droplet-to-layer coalescence. The YOLOv5 deep learning algorithm is employed to identify droplets and evaluate their sizes. A robust phase separator has been developed, demonstrating the capability to achieve rapid phase separation with a throughput of up to 200 mL/min. Furthermore, the study examines the effects of electrolyte concentration, phase ratio, flow rate, and the voltage and frequency of the electric field on phase separation. The synergistic effect of the design in enhancing phase separation at high throughput is confirmed.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121369"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.ces.2025.121367
Desheng Chen , Chenlu Zhang , Aoqi Feng , Tingting Wang , Zhe Lin
In this study, glycerol solution was used to study the collision process of moving droplets and sessile droplets at different viscosities. Two typical collision states, compression and rebound, are photographed by a high-speed camera. The experimental results show that complete rebound occurs under low Weber number (We), and the rebound We range increases with the droplet viscosity. A liquid cap is generated under high We. As We increases, the dimensionless maximum rebound height increases and the contact time decreases, following an inverse proportional function. The research results help in understanding the impact behavior of different viscosities and We on static droplets, providing an important reference for droplet control and application.
{"title":"Experimental study on the dynamics of droplet collisions at different viscosities","authors":"Desheng Chen , Chenlu Zhang , Aoqi Feng , Tingting Wang , Zhe Lin","doi":"10.1016/j.ces.2025.121367","DOIUrl":"10.1016/j.ces.2025.121367","url":null,"abstract":"<div><div>In this study, glycerol solution was used to study the collision process of moving droplets and sessile droplets at different viscosities. Two typical collision states, compression and rebound, are photographed by a high-speed camera. The experimental results show that complete rebound occurs under low Weber number (<em>We</em>), and the rebound <em>We</em> range increases with the droplet viscosity. A liquid cap is generated under high <em>We</em>. As <em>We</em> increases, the dimensionless maximum rebound height increases and the contact time decreases, following an inverse proportional function. The research results help in understanding the impact behavior of different viscosities and <em>We</em> on static droplets, providing an important reference for droplet control and application.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121367"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.ces.2025.121368
Prashant Kumar, Sudhakar Subudhi, Arup Kumar Das
We present an in-depth analysis of sequential ice formation and melt dynamics of both impact deposited and sessile drop. Phenomena like contact line arrest during freezing, ice tip singularity, surface and bulk melting in the deposited drop are shown through careful observations of the free surface and interface. Furthermore, for melting phenomenon surface and bulk melting is observed for deposited droplet and only bulk melting for sessile droplets. For the deposited droplet freezing, the surface temperature has been varied from −10 °C to −60 °C and Weber number has been varied from 2.4 to 18 to get their effect on ice contact angle and contact diameter. Differences in interfacial features during solidification-melting of deposited and sessile drops are also evaluated. Moreover, freezing and melting phenomenon of sessile drop on inclined surfaces showed that for inclined surface angle change from 0° to 75°, the tip asymmetry changes from 0° to 15°.
{"title":"Understanding interfacial dynamics during freezing and melting of deposited and sessile water droplets","authors":"Prashant Kumar, Sudhakar Subudhi, Arup Kumar Das","doi":"10.1016/j.ces.2025.121368","DOIUrl":"10.1016/j.ces.2025.121368","url":null,"abstract":"<div><div>We present an in-depth analysis of sequential ice formation and melt dynamics of both impact deposited and sessile drop. Phenomena like contact line arrest during freezing, ice tip singularity, surface and bulk melting in the deposited drop are shown through careful observations of the free surface and interface. Furthermore, for melting phenomenon surface and bulk melting is observed for deposited droplet and only bulk melting for sessile droplets. For the deposited droplet freezing, the surface temperature has been varied from −10 °C to −60 °C and Weber number has been varied from 2.4 to 18 to get their effect on ice contact angle and contact diameter. Differences in interfacial features during solidification-melting of deposited and sessile drops are also evaluated. Moreover, freezing and melting phenomenon of sessile drop on inclined surfaces showed that for inclined surface angle change from 0° to 75°, the tip asymmetry changes from 0° to 15°.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121368"},"PeriodicalIF":4.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-12DOI: 10.1016/j.ces.2025.121349
Bohan Feng , Yicong Bao , Yuechang Wei , Dong Li , Jing Xiong , Zhen Zhao , Yunpeng Liu , Weiyu Song , Chunming Xu , Jian Liu
The single atom sites have been identified as the optimal structure for structure-insensitive alkane dehydrogenation reaction. However, single atoms with high surface energy suffer from sintering deactivation due to high-temperature conditions. Herein, we report the single cobalt (Co) atoms confined by the ZrO2 lattice for the propane non-oxidative dehydrogenation (PDH) reaction. Compared with surface Co species, the lattice-confined effect of ZrO2 basement prevents the structural transformation of single Co atoms and enriches the active site of Co-O-Zr. The Co single-atom catalyst shows remarkable activity (1.58 mmol g-1h−1) and achieves significantly more substantial regeneration stability than the catalysts with surface CoOx species. The research on lattice-confined Co-ZrO2 catalysts provides a novel cognition for the lattice-confined effect and gives opportunities for the application of thermodynamically stable single-atom catalysts in the future.
{"title":"Lattice-Confined single cobalt atom in ZrO2 for propane non-oxidative dehydrogenation","authors":"Bohan Feng , Yicong Bao , Yuechang Wei , Dong Li , Jing Xiong , Zhen Zhao , Yunpeng Liu , Weiyu Song , Chunming Xu , Jian Liu","doi":"10.1016/j.ces.2025.121349","DOIUrl":"10.1016/j.ces.2025.121349","url":null,"abstract":"<div><div>The single atom sites have been identified as the optimal structure for structure-insensitive alkane dehydrogenation reaction. However, single atoms with high surface energy suffer from sintering deactivation due to high-temperature conditions. Herein, we report the single cobalt (Co) atoms confined by the ZrO<sub>2</sub> lattice for the propane non-oxidative dehydrogenation (PDH) reaction. Compared with surface Co species, the lattice-confined effect of ZrO<sub>2</sub> basement prevents the structural transformation of single Co atoms and enriches the active site of Co-O-Zr. The Co single-atom catalyst shows remarkable activity (1.58 mmol g<sup>-1</sup>h<sup>−1</sup>) and achieves significantly more substantial regeneration stability than the catalysts with surface CoO<sub>x</sub> species. The research on lattice-confined Co-ZrO<sub>2</sub> catalysts provides a novel cognition for the lattice-confined effect and gives opportunities for the application of thermodynamically stable single-atom catalysts in the future.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"307 ","pages":"Article 121349"},"PeriodicalIF":4.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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