Pub Date : 2024-12-28DOI: 10.1016/j.micromeso.2024.113485
Haijun Tan, Yi Yang , Na Qiu , Ruihan Tang, Ao Zhou, Jia Luo, Xiangfei Kong, Zhenguang Hu, Fuxin Zhong, Peipei Zhang
Developing porous organic materials for removing radiotoxic iodine from nuclear plant waste and heavy metal Fe3+ is significantly relevant to environmental remediation. To achieve reversible iodine adsorption, 1,6-dibromopyrene is used as the matrix, a unique nitrogen-rich porous organic polymer containing pyrene (PEMA) was tailor-made by introducing a triazine structure through a schiff base reaction. This polymer exhibits high affinity and adsorption capacity for iodine owing to its effective electron-rich adsorption sites, an extended π-conjugated structure and hierarchically porous structure. PEMA displayed remarkable adsorption capacities for saturated iodine vapor (3.19 g g−1) and iodine n-hexane solution (250.39 mg g−1). Furthermore, the fluorescence characteristic of PEMA has been employed for the selective detection of Fe3+ with high sensitivity with a low detection limit of 0.84 μM among a range of metal ions. Meanwhile, PEMA also demonstrates a good adsorption capacity for Fe3+, amounting to 48 mg g−1. These results suggest that PEMA possesses excellent iodine capture capabilities along with detection and adsorption capacities for Fe3+, making it a promising candidate for environmental remediation.
{"title":"Novel N-rich porous organic polymers for reversible iodine capture and selective detecting of Fe (III)","authors":"Haijun Tan, Yi Yang , Na Qiu , Ruihan Tang, Ao Zhou, Jia Luo, Xiangfei Kong, Zhenguang Hu, Fuxin Zhong, Peipei Zhang","doi":"10.1016/j.micromeso.2024.113485","DOIUrl":"10.1016/j.micromeso.2024.113485","url":null,"abstract":"<div><div>Developing porous organic materials for removing radiotoxic iodine from nuclear plant waste and heavy metal Fe<sup>3+</sup> is significantly relevant to environmental remediation. To achieve reversible iodine adsorption, 1,6-dibromopyrene is used as the matrix, a unique nitrogen-rich porous organic polymer containing pyrene (PEMA) was tailor-made by introducing a triazine structure through a schiff base reaction. This polymer exhibits high affinity and adsorption capacity for iodine owing to its effective electron-rich adsorption sites, an extended π-conjugated structure and hierarchically porous structure. PEMA displayed remarkable adsorption capacities for saturated iodine vapor (3.19 g g<sup>−1</sup>) and iodine n-hexane solution (250.39 mg g<sup>−1</sup>). Furthermore, the fluorescence characteristic of PEMA has been employed for the selective detection of Fe<sup>3+</sup> with high sensitivity with a low detection limit of 0.84 μM among a range of metal ions. Meanwhile, PEMA also demonstrates a good adsorption capacity for Fe<sup>3+</sup>, amounting to 48 mg g<sup>−1</sup>. These results suggest that PEMA possesses excellent iodine capture capabilities along with detection and adsorption capacities for Fe<sup>3+</sup>, making it a promising candidate for environmental remediation.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"385 ","pages":"Article 113485"},"PeriodicalIF":4.8,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-28DOI: 10.1016/j.micromeso.2024.113484
Rui Gao, Mengxin Li, Yuanxue Li
This study aimed to synthesize drug-loaded hyper-crosslinked porous polymers (HCPs) under high-temperature, anhydrous, oxygen-free conditions through a Friedel–Crafts reaction. The resulting hyper-crosslinked porous polymers were characterized by infrared spectroscopy, nitrogen adsorption porosity measurements, thermo-gravimetric analysis, field-emission scanning electron microscopy, and powder X-ray diffraction for HCPs, and the electrochemical properties were investigated. The specific surface areas of the hyper-crosslinked porous polymers reached as high as 1079 m2g−1. We next investigated the use of one of the HCP samples as a drug delivery system and demonstrated its ability to release the model drug ibuprofen. Under selected synthesis conditions, the loading efficiency of the HCP with ibuprofen was 35 % (w/w). The release of the drug was also monitored, and 88 % of the loaded drug was released within 12 h. The resulting hyper-crosslinked porous polymer can be used as a matrix for the in vitro loading of ibuprofen.
{"title":"Synthesis of hyper-crosslinked porous polymers for drug release","authors":"Rui Gao, Mengxin Li, Yuanxue Li","doi":"10.1016/j.micromeso.2024.113484","DOIUrl":"10.1016/j.micromeso.2024.113484","url":null,"abstract":"<div><div>This study aimed to synthesize drug-loaded hyper-crosslinked porous polymers (HCPs) under high-temperature, anhydrous, oxygen-free conditions through a Friedel–Crafts reaction. The resulting hyper-crosslinked porous polymers were characterized by infrared spectroscopy, nitrogen adsorption porosity measurements, thermo-gravimetric analysis, field-emission scanning electron microscopy, and powder X-ray diffraction for HCPs, and the electrochemical properties were investigated. The specific surface areas of the hyper-crosslinked porous polymers reached as high as 1079 m<sup>2</sup>g<sup>−1</sup>. We next investigated the use of one of the HCP samples as a drug delivery system and demonstrated its ability to release the model drug ibuprofen. Under selected synthesis conditions, the loading efficiency of the HCP with ibuprofen was 35 % (w/w). The release of the drug was also monitored, and 88 % of the loaded drug was released within 12 h. The resulting hyper-crosslinked porous polymer can be used as a matrix for the in vitro loading of ibuprofen.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"386 ","pages":"Article 113484"},"PeriodicalIF":4.8,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-27DOI: 10.1016/j.micromeso.2024.113483
Sarah Haghjoo , Mohammad Kavand , Christian L. Lengauer , Hossein Kazemian , Mahmoud Roushani
This study explores the synthesis of a novel and efficient NaP1 zeolite from Austrian fly ash (AFA), composited with Fe3O4 nanoparticles (NPs) and lanthanum hydroxides [La(OH)3]. The composite's efficacy was tested for simultaneously adsorbing glyphosate (GLY), glufosinate (Glu), and aminomethylphosphonic acid (AMPA) from water solution. The inclusion of Fe3O4 NPs and La(OH)3 enhanced the nanoadsorbent's rapid and effective separation capabilities. Significantly, an innovative kinetic model, the Film-Pore-[Concentration-Dependent] Surface Diffusion Model (FPCDSD), was developed to analyze adsorption mechanisms, aligning with experimental results and accurately predicting adsorption processes in single and competitive scenarios. The model used detailed calculations to evaluate mass transfer resistances, employing parameters like rotation speed, adsorbent dosage, and initial concentrations to correlate adsorption data under various conditions. The study found that adsorption capacity retained 92 % effectiveness after 10 adsorption-desorption cycles, consistent with previous research. Results indicated that electrostatic interactions, herbicide affinity for La and Fe complexes, hydrogen bonding, and surface and pore diffusion likely drive adsorption mechanisms. Laboratory tests showed that Gly achieved the Maximum Residual Level (MRL) of 0.1 μg/L as per the European directive for drinking water with 99.95 % removal efficiency, suggesting that NaP1-Fe3O4-La(OH)3 is a highly effective option for water treatment.
{"title":"Enhanced herbicide removal using an innovative NaP1-Fe3O4-La(OH)3 zeolite: Advances in water treatment and experimental modeling","authors":"Sarah Haghjoo , Mohammad Kavand , Christian L. Lengauer , Hossein Kazemian , Mahmoud Roushani","doi":"10.1016/j.micromeso.2024.113483","DOIUrl":"10.1016/j.micromeso.2024.113483","url":null,"abstract":"<div><div>This study explores the synthesis of a novel and efficient NaP1 zeolite from Austrian fly ash (AFA), composited with Fe<sub>3</sub>O<sub>4</sub> nanoparticles (NPs) and lanthanum hydroxides [La(OH)<sub>3</sub>]. The composite's efficacy was tested for simultaneously adsorbing glyphosate (GLY), glufosinate (Glu), and aminomethylphosphonic acid (AMPA) from water solution. The inclusion of Fe<sub>3</sub>O<sub>4</sub> NPs and La(OH)<sub>3</sub> enhanced the nanoadsorbent's rapid and effective separation capabilities. Significantly, an innovative kinetic model, the Film-Pore-[Concentration-Dependent] Surface Diffusion Model (FPCDSD), was developed to analyze adsorption mechanisms, aligning with experimental results and accurately predicting adsorption processes in single and competitive scenarios. The model used detailed calculations to evaluate mass transfer resistances, employing parameters like rotation speed, adsorbent dosage, and initial concentrations to correlate adsorption data under various conditions. The study found that adsorption capacity retained 92 % effectiveness after 10 adsorption-desorption cycles, consistent with previous research. Results indicated that electrostatic interactions, herbicide affinity for La and Fe complexes, hydrogen bonding, and surface and pore diffusion likely drive adsorption mechanisms. Laboratory tests showed that Gly achieved the Maximum Residual Level (MRL) of 0.1 μg/L as per the European directive for drinking water with 99.95 % removal efficiency, suggesting that NaP1-Fe<sub>3</sub>O<sub>4</sub>-La(OH)<sub>3</sub> is a highly effective option for water treatment.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"386 ","pages":"Article 113483"},"PeriodicalIF":4.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-27DOI: 10.1016/j.micromeso.2024.113482
Lipeng Zhou , Haojie Zhang , Aiying Guo , Mengqing Wang , Zhihao Chen , Yunlai Su , Xiaomei Yang
Sn-Beta is a good Lewis acid catalyst. Typically, the organic template in as-made Sn-Beta was removed by calcination in air atmosphere at high temperature (≥500 °C). The fast combustion of organic template in air would lead that the actual temperature of sample is out of control, which will result in the partial disintegration of framework Sn species that are the active centers for catalytic reactions. In this work, ozonization at mild conditions (≤200 °C) was used to remove the organic template. It was found that the ozonization temperature greatly affected the template removal. The template removal efficiency reached 89 % at 120 °C for 3 h. The ozonized Sn-Beta has more framework Sn sites than Sn-Beta-C, for which the template was removed by traditional calcination route. However, the ozonized Sn-Beta showed slightly poor performance for conversion of glucose to methyl lactate (MLA) than Sn-Beta-C due to the presence of a few organic template. After the template residues were further removed by calcination of the ozonized Sn-Beta in air at 200–250 °C for 1 h, the catalytic performance of the ozonized Sn-Beta was significantly improved. Glucose conversion of 98.9 % with 48.7 % yield to MLA at 140 °C for 5 h was obtained over the ozonized Sn-Beta re-calcinated at 200 °C for 1 h.
{"title":"Effect of low-temperature ozonation-assisted detemplation on the properties and catalytic performance of Sn-Beta zeolite","authors":"Lipeng Zhou , Haojie Zhang , Aiying Guo , Mengqing Wang , Zhihao Chen , Yunlai Su , Xiaomei Yang","doi":"10.1016/j.micromeso.2024.113482","DOIUrl":"10.1016/j.micromeso.2024.113482","url":null,"abstract":"<div><div>Sn-Beta is a good Lewis acid catalyst. Typically, the organic template in as-made Sn-Beta was removed by calcination in air atmosphere at high temperature (≥500 °C). The fast combustion of organic template in air would lead that the actual temperature of sample is out of control, which will result in the partial disintegration of framework Sn species that are the active centers for catalytic reactions. In this work, ozonization at mild conditions (≤200 °C) was used to remove the organic template. It was found that the ozonization temperature greatly affected the template removal. The template removal efficiency reached 89 % at 120 °C for 3 h. The ozonized Sn-Beta has more framework Sn sites than Sn-Beta-C, for which the template was removed by traditional calcination route. However, the ozonized Sn-Beta showed slightly poor performance for conversion of glucose to methyl lactate (MLA) than Sn-Beta-C due to the presence of a few organic template. After the template residues were further removed by calcination of the ozonized Sn-Beta in air at 200–250 °C for 1 h, the catalytic performance of the ozonized Sn-Beta was significantly improved. Glucose conversion of 98.9 % with 48.7 % yield to MLA at 140 °C for 5 h was obtained over the ozonized Sn-Beta re-calcinated at 200 °C for 1 h.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"385 ","pages":"Article 113482"},"PeriodicalIF":4.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1016/j.micromeso.2024.113481
Wuqiang Si , Wenlong Hu , Wei Wang , Xiaomei Zhang , Xianliang Zhao , Zhongqing Ma , Yanhong Wang , Chuang Xing
Simplicity and environmental friendliness are essential for zeolite synthesis. Here, we report that NaY (NaY-R) zeolite is accomplished over an ambient pressure environment and adopt rice hush ash as silicon source. A floated sealant on zeolite gel may cleverly creates a quasi-sealed environment for reducing water evaporation. Importantly, the catalytic performances of Co loading NaY-R (Co/NaY-R) on a dual-bed catalytic system with ZSM-5 or Beta zeolite are comparable to those of the corresponding catalytic system formed by commercial NaY zeolite (NaY-C). Meanwhile, dual-bed catalytic systems show significantly enhanced selectivity for gasoline ranged hydrocarbons (C5-11) and isoparaffins compared to the pristine Co/NaY. These results indicate the proposed synthetic protocol can achieve green, safe, and energy-saving synthesis of NaY zeolite, which enriches the insight into designing novel zeolite synthetic route.
{"title":"Dual-bed configuration with eco-friendly NaY synthesis promotes isoparaffin formation from syngas","authors":"Wuqiang Si , Wenlong Hu , Wei Wang , Xiaomei Zhang , Xianliang Zhao , Zhongqing Ma , Yanhong Wang , Chuang Xing","doi":"10.1016/j.micromeso.2024.113481","DOIUrl":"10.1016/j.micromeso.2024.113481","url":null,"abstract":"<div><div>Simplicity and environmental friendliness are essential for zeolite synthesis. Here, we report that NaY (NaY-R) zeolite is accomplished over an ambient pressure environment and adopt rice hush ash as silicon source. A floated sealant on zeolite gel may cleverly creates a quasi-sealed environment for reducing water evaporation. Importantly, the catalytic performances of Co loading NaY-R (Co/NaY-R) on a dual-bed catalytic system with ZSM-5 or Beta zeolite are comparable to those of the corresponding catalytic system formed by commercial NaY zeolite (NaY-C). Meanwhile, dual-bed catalytic systems show significantly enhanced selectivity for gasoline ranged hydrocarbons (C<sub>5-11</sub>) and isoparaffins compared to the pristine Co/NaY. These results indicate the proposed synthetic protocol can achieve green, safe, and energy-saving synthesis of NaY zeolite, which enriches the insight into designing novel zeolite synthetic route.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"385 ","pages":"Article 113481"},"PeriodicalIF":4.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1016/j.micromeso.2024.113480
Botagoz Zhakisheva , Juan José Gutiérrez-Sevillano , Sofia Calero
We performed Monte Carlo molecular simulations in RMC and GCMC ensembles, to study the impact of Na+ charge-balancing cations in the aluminum-substituted zeolites on the adsorption behavior of H2, N2, and NH3. The adsorption isotherms were obtained for single-component gas adsorption and adsorption from the ammonia synthesis reaction mixture. Our findings indicate that the presence of Na+ cations in zeolites alters the adsorptive characteristics of all the molecules under the study. Specifically, Na+ cations have a significant influence on the adsorption behavior of ammonia, effectively preventing its phase transition. Adsorption from the mixture showed that Na + cations enhanced the selectivity of ammonia adsorption over N2, and H2, as compared to pure-silica zeolites. Further, the impact of cations on the reaction equilibrium under the confinement of FAU zeolite was investigated. The confinement effect in ammonia production was shown to be improved due to the presence of cations. We suggest that the optimal conditions for the process can be reached at 573 K and 10 bar, providing a good value of 0.93 of ammonia mole fraction adsorbed.
{"title":"The effect of cations on the ammonia synthesis reaction under the confinement in FAU zeolites","authors":"Botagoz Zhakisheva , Juan José Gutiérrez-Sevillano , Sofia Calero","doi":"10.1016/j.micromeso.2024.113480","DOIUrl":"10.1016/j.micromeso.2024.113480","url":null,"abstract":"<div><div>We performed Monte Carlo molecular simulations in RMC and GCMC ensembles, to study the impact of Na<sup>+</sup> charge-balancing cations in the aluminum-substituted zeolites on the adsorption behavior of H<sub>2</sub>, N<sub>2</sub>, and NH<sub>3</sub>. The adsorption isotherms were obtained for single-component gas adsorption and adsorption from the ammonia synthesis reaction mixture. Our findings indicate that the presence of Na<sup>+</sup> cations in zeolites alters the adsorptive characteristics of all the molecules under the study. Specifically, Na<sup>+</sup> cations have a significant influence on the adsorption behavior of ammonia, effectively preventing its phase transition. Adsorption from the mixture showed that Na <sup>+</sup> cations enhanced the selectivity of ammonia adsorption over N<sub>2</sub>, and H<sub>2</sub>, as compared to pure-silica zeolites. Further, the impact of cations on the reaction equilibrium under the confinement of FAU zeolite was investigated. The confinement effect in ammonia production was shown to be improved due to the presence of cations. We suggest that the optimal conditions for the process can be reached at 573 K and 10 bar, providing a good value of 0.93 of ammonia mole fraction adsorbed.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"385 ","pages":"Article 113480"},"PeriodicalIF":4.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-24DOI: 10.1016/j.micromeso.2024.113479
Italo Iury de Souza Guida , Elaine Sá Menezes Cutrim , Aluisio Cabral , Aline Scaramuzza Aquino , Katia Bernardo-Gusmão , Ana C.S. Alcântara , Luis Gómez-Hortigüela , Alex Rojas
In this work, we study the structure-directing effect of three different cations based on 1,2-dimethylimidazolium moieties linked by a linear bridge of n = 3, 4 or 5 methylene groups (3BDMI, 4BDMI, and 5BDMI, respectively), for the synthesis of silicoaluminophosphate and aluminophosphate microporous molecular sieves. These cations allowed the crystallization of three different structures (AFI, SFO and SAS), presenting different specificity for these phases. They all yielded zeolite AFI, which is considered a default structure; nevertheless, 3BDMI and 4BDMI cations (in AlPO and SAPO compositions) tend to favor the crystallization of PST-27, a monoclinic version of the AFI structure. The crystallization of the SAS and SFO phases depended on the mineralizing agents (fluoride or hydroxide), and was only afforded in SAPO composition; when the synthesis was carried out in hydroxide medium, the three OSDA induced the crystallization of the SAS framework. In contrast, the SFO zeolite was yielded under fluoride medium, and only with 3BDMI and 4BDMI cations. In an attempt to understand the structure-directing behavior of these cations, molecular simulations were carried out to study the locations and conformations of the dications in each of these frameworks. In the case of SAS, cavities were filled with two imidazolium rings of consecutive cations, which site stacked to each other stabilized through π···π interactions between imidazolium rings. In the SFO framework, the organic dications arranged in a zig-zag like conformation, siting their imidazolium rings in consecutive lateral side-pockets. On the other hand, the materials obtained were applied as catalysts for the cycloaddition of CO2 in epoxide reactions, exhibiting interesting catalytic activities.
{"title":"Aluminophosphates and Silicoaluminophosphates Zeolites tailored by different Imidazolium Cations and their evaluation as catalysts for CO2-Epoxide Cycloaddition","authors":"Italo Iury de Souza Guida , Elaine Sá Menezes Cutrim , Aluisio Cabral , Aline Scaramuzza Aquino , Katia Bernardo-Gusmão , Ana C.S. Alcântara , Luis Gómez-Hortigüela , Alex Rojas","doi":"10.1016/j.micromeso.2024.113479","DOIUrl":"10.1016/j.micromeso.2024.113479","url":null,"abstract":"<div><div>In this work, we study the structure-directing effect of three different cations based on 1,2-dimethylimidazolium moieties linked by a linear bridge of <em>n</em> = 3, 4 or 5 methylene groups (3BDMI, 4BDMI, and 5BDMI, respectively), for the synthesis of silicoaluminophosphate and aluminophosphate microporous molecular sieves. These cations allowed the crystallization of three different structures (<strong>AFI</strong>, <strong>SFO</strong> and <strong>SAS</strong>), presenting different specificity for these phases. They all yielded zeolite <strong>AFI</strong>, which is considered a default structure; nevertheless, 3BDMI and 4BDMI cations (in AlPO and SAPO compositions) tend to favor the crystallization of <strong>PST-27,</strong> a monoclinic version of the AFI structure. The crystallization of the <strong>SAS</strong> and <strong>SFO</strong> phases depended on the mineralizing agents (fluoride or hydroxide), and was only afforded in SAPO composition; when the synthesis was carried out in hydroxide medium, the three OSDA induced the crystallization of the <strong>SAS</strong> framework. In contrast, the <strong>SFO</strong> zeolite was yielded under fluoride medium, and only with 3BDMI and 4BDMI cations. In an attempt to understand the structure-directing behavior of these cations, molecular simulations were carried out to study the locations and conformations of the dications in each of these frameworks. In the case of <strong>SAS</strong>, cavities were filled with two imidazolium rings of consecutive cations, which site stacked to each other stabilized through π···π interactions between imidazolium rings. In the <strong>SFO</strong> framework, the organic dications arranged in a zig-zag like conformation, siting their imidazolium rings in consecutive lateral side-pockets. On the other hand, the materials obtained were applied as catalysts for the cycloaddition of CO<sub>2</sub> in epoxide reactions, exhibiting interesting catalytic activities.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"385 ","pages":"Article 113479"},"PeriodicalIF":4.8,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-22DOI: 10.1016/j.micromeso.2024.113466
Xiao Han , Jianfeng Tang , Ran Kong , Han Xue , Wenhui Wang
In order to achieve widespread application of hydrogen in various fields, separating and purifying it from hydrogen-containing mixtures is crucial for the production of H2. Currently, many membrane materials have been developed for separating H2 from its mixtures. Because of its high permeability, selectivity and strong stability, the carbon molecular sieve membranes (CMSMs) have obvious advantages in the field of H2 separation. In the present study, firstly, the preparation process of CMSMs was reviewed, and the parameters that determine the permeability and screening performance of CMSMs were analyzed, including the selection of precursors and inorganic fillers, and the determination of pyrolysis conditions. Secondly, by analyzing the transfer mechanism of gas in CMSMs, the evaluation method of H2's separation performance in CMSMs was determined. In addition, the effects of process operating conditions, such as pressure ratio, temperature, hydrogen mixing ratio, flow ratio, purging/evacuation and humidity, on the permeability of hydrogen separation by CMSMs were summarized. Finally, based on the summary analysis of the obtained results, a set of recommendations were put forth for the future development of CMSMs for separating hydrogen from its mixtures.
{"title":"Research progress of carbon molecular sieve membranes suitable for hydrogen separation","authors":"Xiao Han , Jianfeng Tang , Ran Kong , Han Xue , Wenhui Wang","doi":"10.1016/j.micromeso.2024.113466","DOIUrl":"10.1016/j.micromeso.2024.113466","url":null,"abstract":"<div><div>In order to achieve widespread application of hydrogen in various fields, separating and purifying it from hydrogen-containing mixtures is crucial for the production of H<sub>2</sub>. Currently, many membrane materials have been developed for separating H<sub>2</sub> from its mixtures. Because of its high permeability, selectivity and strong stability, the carbon molecular sieve membranes (CMSMs) have obvious advantages in the field of H<sub>2</sub> separation. In the present study, firstly, the preparation process of CMSMs was reviewed, and the parameters that determine the permeability and screening performance of CMSMs were analyzed, including the selection of precursors and inorganic fillers, and the determination of pyrolysis conditions. Secondly, by analyzing the transfer mechanism of gas in CMSMs, the evaluation method of H<sub>2</sub>'s separation performance in CMSMs was determined. In addition, the effects of process operating conditions, such as pressure ratio, temperature, hydrogen mixing ratio, flow ratio, purging/evacuation and humidity, on the permeability of hydrogen separation by CMSMs were summarized. Finally, based on the summary analysis of the obtained results, a set of recommendations were put forth for the future development of CMSMs for separating hydrogen from its mixtures.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"387 ","pages":"Article 113466"},"PeriodicalIF":4.8,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-19DOI: 10.1016/j.micromeso.2024.113468
Lisha Wei , Hui Yang , Bo Qin , Tong Zhang , Yanze Du , Ruifeng Li , Xiao-Dong Wen , Haijun Jiao
Due to the practical importance of Y zeolites in catalytic hydrocracking of polyaromatic hydrocarbons, the detailed mechanisms of 9,10-dihydroanthracene catalytic hydrocracking on HY zeolite with different Al substitution (1Al, 3Al, 6Al; Si/Al = 47, 15, 7) and 6Al with trinuclear extra-framework Al (EFAl) in the sodalite cage (6Al + EFAl, Si/Al = 4.67) in different acid number and strength have been computed. It is found that the heterolytic activation of H2 encapsulated within a conjugated Frustrated Lewis Pair (FLP), generated by the transfer of acidic O-H proton to hydrocarbon substrate, is the rate-determining step for the formation of 1-benzyl-2-methylbenzene and its conversion to benzene, toluene, and o-xylene. A correlation between Brønsted acid strength (enthalpy of adsorption of pyridine) and catalytic activity (apparent Gibbs free energy barrier) has been found, e.g., a higher acid strength corresponds to a lower apparent Gibbs free energy barrier and therefore higher catalytic activity. Since the conversion of 1-benzyl-2-methylbenzene has lower apparent Gibbs free energy barrier than its formation, its detection under the reaction condition is difficult or unlikely.
{"title":"Catalytic hydrocracking of 9,10-dihydroanthracene on HY zeolite – Activity dependence on acid strength","authors":"Lisha Wei , Hui Yang , Bo Qin , Tong Zhang , Yanze Du , Ruifeng Li , Xiao-Dong Wen , Haijun Jiao","doi":"10.1016/j.micromeso.2024.113468","DOIUrl":"10.1016/j.micromeso.2024.113468","url":null,"abstract":"<div><div>Due to the practical importance of Y zeolites in catalytic hydrocracking of polyaromatic hydrocarbons, the detailed mechanisms of 9,10-dihydroanthracene catalytic hydrocracking on HY zeolite with different Al substitution (1Al, 3Al, 6Al; Si/Al = 47, 15, 7) and 6Al with trinuclear extra-framework Al (EFAl) in the sodalite cage (6Al + EFAl, Si/Al = 4.67) in different acid number and strength have been computed. It is found that the heterolytic activation of H<sub>2</sub> encapsulated within a conjugated Frustrated Lewis Pair (FLP), generated by the transfer of acidic O-H proton to hydrocarbon substrate, is the rate-determining step for the formation of 1-benzyl-2-methylbenzene and its conversion to benzene, toluene, and <em>o</em>-xylene. A correlation between Brønsted acid strength (enthalpy of adsorption of pyridine) and catalytic activity (apparent Gibbs free energy barrier) has been found, e.g., a higher acid strength corresponds to a lower apparent Gibbs free energy barrier and therefore higher catalytic activity. Since the conversion of 1-benzyl-2-methylbenzene has lower apparent Gibbs free energy barrier than its formation, its detection under the reaction condition is difficult or unlikely.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"385 ","pages":"Article 113468"},"PeriodicalIF":4.8,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-18DOI: 10.1016/j.micromeso.2024.113465
Minghui Hu , Zhipeng Qie , Zhongbao Liu , Xuanpeng Lu , Shiyang Bai , Li Lv , Zepeng Wang , Huaizhong Xiang , Xiaoxia Ou , Yuanye Zhuang
High-performance carbon dioxide (CO2) capture in environments with high humidity remains a significant challenge. In this study, we proposed a sequential post-treatment method using carboxylic acids (oxalic acid, OA, and ethylenediaminetetraacetic acid, EDTA) followed by ammonium hydroxide (NH4OH) treatment to enhance the CO2/H2O adsorption selectivity of zeolite adsorbents. This method was found effective for Y, Beta, and MOR zeolites, in which MOR zeolites with sequential OA and NH4OH (OA-NH4OH) treatment demonstrated the optimal CO2/H2O selectivity and the longest CO2 breakthrough time in dynamic adsorption at 75 % relative humidity (RH). The outstanding performance can be attributed to its well-preserved porosity and improved surface silicon-to-aluminum ratio. Based on advanced characterizations such as CO2 physisorption and solid state 27Al NMR, the mechanism for OA-NH4 treatment was proposed as follows: first, OA treatment increased the micropore volume by restoring partially coordinated Al (IV-2) species, subsequently, NH4OH treatment removed Al (VI) (i.e., extra framework Al species) from the MOR zeolites. The sequential OA-NH4OH treatment collectively boosted the zeolite's affinity for CO2. Additionally, the modified zeolite adsorbent exhibited excellent recyclability, with a CO2 adsorption capacity loss of less than 1 wt% over five cycles. This study offers new insights into developing “water-resistant” zeolite adsorbents through simple post-treatment approaches.
{"title":"Sequential carboxylic acid and ammonium hydroxide treatments for zeolites: Enhancing CO2 adsorption under humid conditions","authors":"Minghui Hu , Zhipeng Qie , Zhongbao Liu , Xuanpeng Lu , Shiyang Bai , Li Lv , Zepeng Wang , Huaizhong Xiang , Xiaoxia Ou , Yuanye Zhuang","doi":"10.1016/j.micromeso.2024.113465","DOIUrl":"10.1016/j.micromeso.2024.113465","url":null,"abstract":"<div><div>High-performance carbon dioxide (CO<sub>2</sub>) capture in environments with high humidity remains a significant challenge. In this study, we proposed a sequential post-treatment method using carboxylic acids (oxalic acid, OA, and ethylenediaminetetraacetic acid, EDTA) followed by ammonium hydroxide (NH<sub>4</sub>OH) treatment to enhance the CO<sub>2</sub>/H<sub>2</sub>O adsorption selectivity of zeolite adsorbents. This method was found effective for Y, Beta, and MOR zeolites, in which MOR zeolites with sequential OA and NH<sub>4</sub>OH (OA-NH<sub>4</sub>OH) treatment demonstrated the optimal CO<sub>2</sub>/H<sub>2</sub>O selectivity and the longest CO<sub>2</sub> breakthrough time in dynamic adsorption at 75 % relative humidity (RH). The outstanding performance can be attributed to its well-preserved porosity and improved surface silicon-to-aluminum ratio. Based on advanced characterizations such as CO<sub>2</sub> physisorption and solid state <sup>27</sup>Al NMR, the mechanism for OA-NH<sub>4</sub> treatment was proposed as follows: first, OA treatment increased the micropore volume by restoring partially coordinated Al (IV-2) species, subsequently, NH<sub>4</sub>OH treatment removed Al (VI) (i.e., extra framework Al species) from the MOR zeolites. The sequential OA-NH<sub>4</sub>OH treatment collectively boosted the zeolite's affinity for CO<sub>2</sub>. Additionally, the modified zeolite adsorbent exhibited excellent recyclability, with a CO<sub>2</sub> adsorption capacity loss of less than 1 wt% over five cycles. This study offers new insights into developing “water-resistant” zeolite adsorbents through simple post-treatment approaches.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"384 ","pages":"Article 113465"},"PeriodicalIF":4.8,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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