Pub Date : 2024-09-28DOI: 10.1016/j.micromeso.2024.113353
Michael Dyballa, Zheng Li , Daniel Dittmann
Three zeolite catalysts with comparable amounts of aluminum and/or boron ([Al]ZSM-5, [B,Al]ZSM-5, and [B]ZSM-5) are herein synthesized. Water (H2O), ammonia (NH3), acetonitrile-d3 (ACN), and trimethylphosphine oxide (TMPO) are applied as probe molecules to investigate the acidity of the respective materials in combination with 11B, 27Al, and 29Si MAS NMR spectroscopy. Ammonia is not protonated to ammonium on Si(OH)B groups and only LAS-bound ammonia persists desorption. Thus, ammonia gives a realistic, quantitative picture of the present acid sites. ACN interacts only with Si(OH)Al as desired. The strong base TMPO results in a misleading, not quantifiable picture. Subsequent hydration is unsuited to distinguish BAS and LAS densities. The samples were catalytically tested in the conversion of methanol, ethanol, and ethylene. [B]ZSM-5 is unreactive in hydrocarbon formation due to absence of BAS, instead LAS are present. The mixed [B,Al]ZSM-5 shows a decreased lifetime in MTO conversion compared to the [Al]ZSM-5, due to LAS presence. A sometimes reported superior reactivity of [B,Al]ZSM-5 catalysts is thus explained primarily by an optimized BAS density.
本文合成了三种铝和/或硼含量相当的沸石催化剂（[Al]ZSM-5、[B,Al]ZSM-5 和 [B]ZSM-5）。水 (H2O)、氨 (NH3)、乙腈-d3 (ACN) 和三甲基氧化膦 (TMPO) 被用作探针分子，结合 11B、27Al 和 29Si MAS NMR 光谱来研究各自材料的酸性。氨不会在 Si(OH)B 基团上质子化为铵，只有与 LAS 结合的氨才会持续解吸。因此，氨能真实、定量地反映目前的酸性位点。ACN 只与 Si(OH)Al 起作用。而强碱 TMPO 则会产生误导，无法量化。随后的水合作用无法区分 BAS 和 LAS 密度。这些样品在甲醇、乙醇和乙烯的转化过程中进行了催化测试。由于缺乏 BAS，[B]ZSM-5 在碳氢化合物的形成过程中没有反应，反而存在 LAS。与[Al]ZSM-5 相比，混合[B,Al]ZSM-5 在 MTO 转化过程中的寿命缩短，原因是存在 LAS。因此，[B,Al]ZSM-5 催化剂有时被报道具有更高的反应活性，其主要原因是优化了 BAS 密度。
{"title":"Boron vs. aluminum in ZSM-5 zeolites: Solid-state NMR, acidity, and C1/C2 reactant conversion","authors":"Michael Dyballa, Zheng Li , Daniel Dittmann","doi":"10.1016/j.micromeso.2024.113353","DOIUrl":"10.1016/j.micromeso.2024.113353","url":null,"abstract":"<div><div>Three zeolite catalysts with comparable amounts of aluminum and/or boron ([Al]ZSM-5, [B,Al]ZSM-5, and [B]ZSM-5) are herein synthesized. Water (H<sub>2</sub>O), ammonia (NH<sub>3</sub>), acetonitrile-<em>d</em><sub>3</sub> (ACN), and trimethylphosphine oxide (TMPO) are applied as probe molecules to investigate the acidity of the respective materials in combination with <sup>11</sup>B, <sup>27</sup>Al, and <sup>29</sup>Si MAS NMR spectroscopy. Ammonia is not protonated to ammonium on Si(OH)B groups and only LAS-bound ammonia persists desorption. Thus, ammonia gives a realistic, quantitative picture of the present acid sites. ACN interacts only with Si(OH)Al as desired. The strong base TMPO results in a misleading, not quantifiable picture. Subsequent hydration is unsuited to distinguish BAS and LAS densities. The samples were catalytically tested in the conversion of methanol, ethanol, and ethylene. [B]ZSM-5 is unreactive in hydrocarbon formation due to absence of BAS, instead LAS are present. The mixed [B,Al]ZSM-5 shows a decreased lifetime in MTO conversion compared to the [Al]ZSM-5, due to LAS presence. A sometimes reported superior reactivity of [B,Al]ZSM-5 catalysts is thus explained primarily by an optimized BAS density.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113353"},"PeriodicalIF":4.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421421","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}
Microwave heating (MH) is a promising way for zeolite synthesis in terms of rapid and uniform reaction. However, detail process of the synthesis reaction and mechanism of its promotion by microwave are still under investigation. In the present study, LTA (Linde Type-A) zeolite was hydrothermally synthesized by 300 W of MH from hydrolyzed Al and Si alkoxides. The formation process of LTA was elucidated by nuclear magnetic resonance spectroscopy (29Si NMR), small angle X-ray scattering (SAXS), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS) and scanning electron microscopy (SEM). 29Si NMR and SAXS analyses suggest that linear polycondensates of aluminosilicate in the precursor solution was immediately transformed into densely packed structure by MH. TEM observations reveals that crystalline phase with several nanometers was already formed in amorphous aluminosilicate nanoparticles prior to the MH while XRD shows that the amorphous phase had been transformed to LTA phase until 400 min of MH. It is basically consistent with the previous studies among zeolite synthesis assisted by both of conventional heating and MH. The aluminosilicate/LTA particle size was measured by DLS and SEM image as well as the yield was calculated from weight of the reaction products. The particle gradually grew up to 242 nm in diameter until 36 h while the yield sharply increased to nearly 100 % during 6.7 h and 12 h. In other words, all aluminosilicate in the solution once had polycondensed to form insoluble particle until 12 h followed by particle growth by dissolution-reprecipitation or agglomeration until 36 h.
微波加热（MH）反应快速、均匀，是一种很有前景的沸石合成方法。然而，微波合成反应的详细过程及其促进机理仍在研究之中。本研究以水解的 Al 和 Si 烷氧基为原料，通过 300 W 的 MH 水热合成了 LTA（Linde Type-A）沸石。通过核磁共振波谱（29Si NMR）、小角 X 射线散射（SAXS）、X 射线衍射（XRD）、透射电子显微镜（TEM）、动态光散射（DLS）和扫描电子显微镜（SEM）阐明了 LTA 的形成过程。29Si NMR 和 SAXS 分析表明，前驱体溶液中的铝硅酸盐线性聚凝物在 MH 作用下立即转变为致密堆积结构。TEM 观察结果表明，在 MH 之前，无定形的纳米硅酸铝颗粒中已经形成了几纳米的结晶相，而 XRD 则表明，在 MH 400 分钟之前，无定形相已经转变为 LTA 相。这与之前通过常规加热和 MH 两种方法辅助合成沸石的研究结果基本一致。通过 DLS 和 SEM 图像测量了铝硅酸盐/LTA 的粒度，并根据反应产物的重量计算了产率。换句话说，溶液中的所有硅酸铝在 12 小时前已经聚结成不溶解的颗粒，然后在 36 小时前通过溶解-再沉淀或团聚的方式使颗粒长大。
{"title":"Crystallization process of LTA zeolite from alkoxides assisted by microwave heating","authors":"Kazuumi Ito , Yuji Jinbo , Wataru Fujiwara , Takeshi Higuchi","doi":"10.1016/j.micromeso.2024.113343","DOIUrl":"10.1016/j.micromeso.2024.113343","url":null,"abstract":"<div><div>Microwave heating (MH) is a promising way for zeolite synthesis in terms of rapid and uniform reaction. However, detail process of the synthesis reaction and mechanism of its promotion by microwave are still under investigation. In the present study, LTA (Linde Type-A) zeolite was hydrothermally synthesized by 300 W of MH from hydrolyzed Al and Si alkoxides. The formation process of LTA was elucidated by nuclear magnetic resonance spectroscopy (<sup>29</sup>Si NMR), small angle X-ray scattering (SAXS), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS) and scanning electron microscopy (SEM). <sup>29</sup>Si NMR and SAXS analyses suggest that linear polycondensates of aluminosilicate in the precursor solution was immediately transformed into densely packed structure by MH. TEM observations reveals that crystalline phase with several nanometers was already formed in amorphous aluminosilicate nanoparticles prior to the MH while XRD shows that the amorphous phase had been transformed to LTA phase until 400 min of MH. It is basically consistent with the previous studies among zeolite synthesis assisted by both of conventional heating and MH. The aluminosilicate/LTA particle size was measured by DLS and SEM image as well as the yield was calculated from weight of the reaction products. The particle gradually grew up to 242 nm in diameter until 36 h while the yield sharply increased to nearly 100 % during 6.7 h and 12 h. In other words, all aluminosilicate in the solution once had polycondensed to form insoluble particle until 12 h followed by particle growth by dissolution-reprecipitation or agglomeration until 36 h.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113343"},"PeriodicalIF":4.8,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421422","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 : 2024-09-26DOI: 10.1016/j.micromeso.2024.113352
Marvin Kloß, Christian Weinberger, Michael Tiemann
The metal-organic framework CPO-27 exhibits free coordination sites (open metal sites) and can be prepared with a wide range of metals that influence its properties. It is therefore an intriguing structure to study sorption phenomena. We analyze the water resistance and sorption behavior of these frameworks, with particular attention to the sorption mechanism in detail and the structure of the confined water molecules. For this purpose, we use manometric water vapor sorption analysis and FTIR spectroscopy. The respective metal center orchestrates both the adsorption behavior and the arrangement of the water molecules in the micropores of the framework. The extent to which water molecules form hydrogen bonds (with each other and with framework oxygen atoms) plays a crucial role in the stability of the framework towards water. Water adsorption is governed by the coordination of water molecules to the open metal sites (except for CPO-27-Cu) and subsequent H-bonding. A stepwise adsorption of water is observed, with significant differences depending on the choice of metal.
{"title":"Water in the micropores of CPO-27 metal-organic frameworks: A comprehensive study","authors":"Marvin Kloß, Christian Weinberger, Michael Tiemann","doi":"10.1016/j.micromeso.2024.113352","DOIUrl":"10.1016/j.micromeso.2024.113352","url":null,"abstract":"<div><div>The metal-organic framework CPO-27 exhibits free coordination sites (open metal sites) and can be prepared with a wide range of metals that influence its properties. It is therefore an intriguing structure to study sorption phenomena. We analyze the water resistance and sorption behavior of these frameworks, with particular attention to the sorption mechanism in detail and the structure of the confined water molecules. For this purpose, we use manometric water vapor sorption analysis and FTIR spectroscopy. The respective metal center orchestrates both the adsorption behavior and the arrangement of the water molecules in the micropores of the framework. The extent to which water molecules form hydrogen bonds (with each other and with framework oxygen atoms) plays a crucial role in the stability of the framework towards water. Water adsorption is governed by the coordination of water molecules to the open metal sites (except for CPO-27-Cu) and subsequent H-bonding. A stepwise adsorption of water is observed, with significant differences depending on the choice of metal.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113352"},"PeriodicalIF":4.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356823","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}
Discriminatory fluorescence detection of various metal ions is of significant importance in environmental and health-related applications. A luminescent hydrogen-bonded organic framework (HOF) material, PFC-1 was synthesized using 1,3,6,8-tetra(4-carboxylbenzene) pyrene (H4TBAPy) as the organic building block. The fluorescence behavior of PFC-1 is influenced by the concentration of the suspension, demonstrating different emissions characteristic of monomer and excimer fluorescence, which are highly sensitive to the surrounding environment. This allows for the potential differentiation and sensing of different target analytes. PFC-1 showed discriminatory fluorescence sensing performance towards metal ions such as Al3+, Sc3+, Cr3+, and Cu2+, with changes in fluorescence intensity, emission peak shifts, and intensity ratio changes between monomer and excimer emissions. Furthermore, a smartphone-based detection strategy was proposed, leveraging color recognition capabilities of smartphones for onsite and real-time sensing. The work demonstrate that PFC-1 is a promising material for the development of portable, cost-effective fluorescent sensors for onsite and real-time detection of metal ions. The integration of PFC-1 with smartphone technology paves the way for practical applications in environmental monitoring, industrial processes, and healthcare diagnostics.
{"title":"A pyrene-based hydrogen-bonded framework with excimer induced ratiometric emission for discriminative luminescence detection of metal ions","authors":"Penglei Shen , Hui Xu , Tao Zhao , Wei Zhang , Gongxun Bai , Thamraa Alshahrani , Banglin Chen , Junkuo Gao , Shiqing Xu","doi":"10.1016/j.micromeso.2024.113348","DOIUrl":"10.1016/j.micromeso.2024.113348","url":null,"abstract":"<div><div>Discriminatory fluorescence detection of various metal ions is of significant importance in environmental and health-related applications. A luminescent hydrogen-bonded organic framework (HOF) material, PFC-1 was synthesized using 1,3,6,8-tetra(4-carboxylbenzene) pyrene (H<sub>4</sub>TBAPy) as the organic building block. The fluorescence behavior of PFC-1 is influenced by the concentration of the suspension, demonstrating different emissions characteristic of monomer and excimer fluorescence, which are highly sensitive to the surrounding environment. This allows for the potential differentiation and sensing of different target analytes. PFC-1 showed discriminatory fluorescence sensing performance towards metal ions such as Al<sup>3+</sup>, Sc<sup>3+</sup>, Cr<sup>3+</sup>, and Cu<sup>2+</sup>, with changes in fluorescence intensity, emission peak shifts, and intensity ratio changes between monomer and excimer emissions. Furthermore, a smartphone-based detection strategy was proposed, leveraging color recognition capabilities of smartphones for onsite and real-time sensing. The work demonstrate that PFC-1 is a promising material for the development of portable, cost-effective fluorescent sensors for onsite and real-time detection of metal ions. The integration of PFC-1 with smartphone technology paves the way for practical applications in environmental monitoring, industrial processes, and healthcare diagnostics.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113348"},"PeriodicalIF":4.8,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356825","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 : 2024-09-25DOI: 10.1016/j.micromeso.2024.113351
Yiwen Li, Shikuan Xu, Yangyang Zhang, Rui Du, Rong Li, Yanjun Xing
MimDES-ZIF-8 with rich active sites as positive charges and metal coordination sites were prepared based on imidazole based deep eutectic solvent (MimDES) using interface permeation method. 2-Methylimidazole (2-Mim) simultaneously acted as a hydrogen bond acceptor (HBA) in MimDES (hydrogen donner was 1,6-hexanediol) and an organic ligand in MimDES-ZIF-8, affecting the coordination of ZIF-8 during permeation. Four different zinc salt solutions (ZnCl2, Zn(NO3)2·6H2O, Zn(OAc)2·2H2O, ZnSO4·7H2O) were permeated into MimDES to obtain MimDES-ZIF-8 with different morphologies. All MimDES-ZIF-8 had higher Zn/N ration (>0.25), specific surface area and surface positive charges. The dye adsorption results indicated that MimDES-ZIF-8 showed high adsorption efficiencies for acid fuchsin (all exceeded 97.75 % under pH 7.5) and a fast adsorption rate (exceeding 93 % in 5 min and reaching equilibrium in 60 min). Among MimDES-ZIF-8, the adsorption capacity of ZIF-8-C was 4845.3 mg/g. After five cycles of adsorption, the AF removal efficiency of ZIF-8-C remained over 93.23 %. Moreover, ZIF-8-C also had good adsorption capacity for anionic dyes CR, cationic dyes MB and BB. The adsorption process aligned well with both the Langmuir model and the pseudo-second-order kinetic model. Based on FTIR, XPS, and electrostatic potential calculation, the adsorption mechanism was elucidated.
{"title":"Rich active sites ZIF-8 base on imidazole-based deep eutectic solvents for rapid adsorption of acid fuchsin and competitive adsorption","authors":"Yiwen Li, Shikuan Xu, Yangyang Zhang, Rui Du, Rong Li, Yanjun Xing","doi":"10.1016/j.micromeso.2024.113351","DOIUrl":"10.1016/j.micromeso.2024.113351","url":null,"abstract":"<div><div>MimDES-ZIF-8 with rich active sites as positive charges and metal coordination sites were prepared based on imidazole based deep eutectic solvent (MimDES) using interface permeation method. 2-Methylimidazole (2-Mim) simultaneously acted as a hydrogen bond acceptor (HBA) in MimDES (hydrogen donner was 1,6-hexanediol) and an organic ligand in MimDES-ZIF-8, affecting the coordination of ZIF-8 during permeation. Four different zinc salt solutions (ZnCl<sub>2</sub>, Zn(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O, Zn(OAc)<sub>2</sub>·2H<sub>2</sub>O, ZnSO<sub>4</sub>·7H<sub>2</sub>O) were permeated into MimDES to obtain MimDES-ZIF-8 with different morphologies. All MimDES-ZIF-8 had higher Zn/N ration (>0.25), specific surface area and surface positive charges. The dye adsorption results indicated that MimDES-ZIF-8 showed high adsorption efficiencies for acid fuchsin (all exceeded 97.75 % under pH 7.5) and a fast adsorption rate (exceeding 93 % in 5 min and reaching equilibrium in 60 min). Among MimDES-ZIF-8, the adsorption capacity of ZIF-8-C was 4845.3 mg/g. After five cycles of adsorption, the AF removal efficiency of ZIF-8-C remained over 93.23 %. Moreover, ZIF-8-C also had good adsorption capacity for anionic dyes CR, cationic dyes MB and BB. The adsorption process aligned well with both the Langmuir model and the pseudo-second-order kinetic model. Based on FTIR, XPS, and electrostatic potential calculation, the adsorption mechanism was elucidated.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113351"},"PeriodicalIF":4.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326885","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 : 2024-09-24DOI: 10.1016/j.micromeso.2024.113349
Christopher Martínez López, Florianne Castillo-Borja
The residues generated from the anodizing industry contain metallic ions like Al3+, and the presence of these pollutants in water bodies cause serious concern because of the ecological and human health risks. The adsorption of heavy metal ions is a widely used option due to it is an easy to implement, eco-friendly, and cost-effective process. This work reports the effect of different surfaces on the adsorption process of Al3+ ions to clarify the adsorption mechanism of the ions using molecular dynamics simulations. The models of three adsorbents: hydroxyapatite (HAP), an activated carbon (AC), and clinoptilolite (CLI) were computationally investigated to identify the most suitable adsorbent. The calculated adsorption isotherms allowed the evaluation of three different adsorbent materials for the removal of Al3+ ions from an aqueous solution. The findings were compared with experimental data of Al3+ adsorption onto bone char and a good qualitative similarity with experimental data was obtained for the HAP model. The results obtained by simulation as well as the experimental data fit satisfactorily to the Freundlich model, the fitting parameters show differences less than 3 % between the simulated and experimental data. For the three adsorbents, the simulated data fit better to the Freundlich isotherm adsorption model, suggesting heterogeneous adsorption on surfaces with variable adsorption capacity in each case. To study the adsorption mechanism, density profiles, RDFs, number of H-bonds, molecular minimum distances and intermolecular interactions were calculated. The efficiency of Al3+ ion adsorption is strongly influenced by the hydrophilic or amphiphilic nature of the adsorbent surface, as well as by the solvation structure of the ions in the solution. In each system, the solvation phenomenon occurs, although only the AC adsorbent exhibits it to a lesser extent compared to CLI and HAP surfaces. The CLI model had the highest adsorption capacity, due to its intense hydrophilic behavior, which leads to greater affinity and stability in the water molecules adsorbed on its surface and, therefore, allows a greater adsorption of Al3+ ions.
{"title":"Interfacial dynamics of Al3+ ions and water on hydrophilic adsorbents: A molecular dynamics study","authors":"Christopher Martínez López, Florianne Castillo-Borja","doi":"10.1016/j.micromeso.2024.113349","DOIUrl":"10.1016/j.micromeso.2024.113349","url":null,"abstract":"<div><div>The residues generated from the anodizing industry contain metallic ions like Al<sup>3+</sup>, and the presence of these pollutants in water bodies cause serious concern because of the ecological and human health risks. The adsorption of heavy metal ions is a widely used option due to it is an easy to implement, eco-friendly, and cost-effective process. This work reports the effect of different surfaces on the adsorption process of Al<sup>3+</sup> ions to clarify the adsorption mechanism of the ions using molecular dynamics simulations. The models of three adsorbents: hydroxyapatite (HAP), an activated carbon (AC), and clinoptilolite (CLI) were computationally investigated to identify the most suitable adsorbent. The calculated adsorption isotherms allowed the evaluation of three different adsorbent materials for the removal of Al<sup>3+</sup> ions from an aqueous solution. The findings were compared with experimental data of Al<sup>3+</sup> adsorption onto bone char and a good qualitative similarity with experimental data was obtained for the HAP model. The results obtained by simulation as well as the experimental data fit satisfactorily to the Freundlich model, the fitting parameters show differences less than 3 % between the simulated and experimental data. For the three adsorbents, the simulated data fit better to the Freundlich isotherm adsorption model, suggesting heterogeneous adsorption on surfaces with variable adsorption capacity in each case. To study the adsorption mechanism, density profiles, RDFs, number of H-bonds, molecular minimum distances and intermolecular interactions were calculated. The efficiency of Al<sup>3+</sup> ion adsorption is strongly influenced by the hydrophilic or amphiphilic nature of the adsorbent surface, as well as by the solvation structure of the ions in the solution. In each system, the solvation phenomenon occurs, although only the AC adsorbent exhibits it to a lesser extent compared to CLI and HAP surfaces. The CLI model had the highest adsorption capacity, due to its intense hydrophilic behavior, which leads to greater affinity and stability in the water molecules adsorbed on its surface and, therefore, allows a greater adsorption of Al<sup>3+</sup> ions.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113349"},"PeriodicalIF":4.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323613","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}
Zeolite Y serves as an effective adsorbent for VOCs capture due to its ordered porous structure, exceptional thermal stability, chemical resistance and fine-tune key properties. However, the hydrophilicity caused by the low SiO2/Al2O3 ratio seriously limits its industrial application, especially in humid environments. In this work, a series of core-shell composites Y@VTMS-DVBn were prepared through surface grafting and copolymerization. A variety of characterizations were utilized to study the structural and morphological changes of the prepared samples. The dynamic breakthrough adsorption experiment showed that the toluene uptake was significantly improved from 1.77 mg/g to 53.09 mg/g under 30 % relative humidity. Moreover, the core-shell composite exhibited excellent regeneration properties, the adsorption capacity remained 90 % under wet conditions after 6 cycles of regeneration. Adsorption kinetic analysis revealed that the adsorption behavior of toluene on the prepared adsorbents was primarily physical adsorption. These results show that the core-shell composite is a promising candidate for VOCs removal in industrial application.
{"title":"Fabrication of core-shell structural Y@VTMS-DVB composites with enhanced hydrophobicity for toluene capture under humid environment","authors":"Chang Lu, Xi Zhang, Pengfei Zhang, Lingling Ren, Nengjie Feng, Hui Wan, Guofeng Guan","doi":"10.1016/j.micromeso.2024.113350","DOIUrl":"10.1016/j.micromeso.2024.113350","url":null,"abstract":"<div><div>Zeolite Y serves as an effective adsorbent for VOCs capture due to its ordered porous structure, exceptional thermal stability, chemical resistance and fine-tune key properties. However, the hydrophilicity caused by the low SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratio seriously limits its industrial application, especially in humid environments. In this work, a series of core-shell composites Y@VTMS-DVB<sub>n</sub> were prepared through surface grafting and copolymerization. A variety of characterizations were utilized to study the structural and morphological changes of the prepared samples. The dynamic breakthrough adsorption experiment showed that the toluene uptake was significantly improved from 1.77 mg/g to 53.09 mg/g under 30 % relative humidity. Moreover, the core-shell composite exhibited excellent regeneration properties, the adsorption capacity remained 90 % under wet conditions after 6 cycles of regeneration. Adsorption kinetic analysis revealed that the adsorption behavior of toluene on the prepared adsorbents was primarily physical adsorption. These results show that the core-shell composite is a promising candidate for VOCs removal in industrial application.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113350"},"PeriodicalIF":4.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323610","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 : 2024-09-22DOI: 10.1016/j.micromeso.2024.113347
Shuang Tan , Francesco Dalena , Igor E. Golub , Eddy Dib , Oleg A. Filippov , Ludovica Pace , Rémy Guillet-Nicolas , Valentin Valtchev , Hailing Guo , Svetlana Mintova
The incorporation of heteroatoms (X) into the zeolite-templated carbon (ZTC) structure is a widely used technique to tailor its properties for specific applications such as gas adsorption, methane and hydrogen storage, and catalysis. However, the literature lacks sufficient data on Fourier-transform infrared spectroscopy (FTIR) analysis of ZTCs due to the challenge in obtaining high-quality FTIR spectra required for accurate assignment of the C–X bands, primarily caused by the black mass effect. In this work we prepared nitrogen (N) and phosphorus (P) doped ZTC samples using FAU type zeolite as a template and furfuryl alcohol as a carbon precursor. The Raman results confirmed the presence of medium-sized aromatic structures and also showed that doping these structures with N and P leads to some defects, although the overall conformation remains structurally intact. The FTIR spectra of the ZTC materials were obtained by controlling the preparation procedure and humidity, enabling clear analysis of the black samples. A Density Functional Theory (DFT) model based on the dimeric buckybowl structure was developed and complemented by experimental results obtained from X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and FTIR. The proposed DFT model was then used for deconvolution and precise band assignment of the experimental FTIR spectra. The FTIR deconvolution study also supported the incorporation of N and P into the ZTC as well as the presence of primarily two types of nitrogen species, amide (primary and secondary) and pyridine-like, while P was mainly incorporated as triphenylphosphine oxide and phosphonic acid.
{"title":"Spectroscopic characterization of black N- and P-doped zeolite templated carbons","authors":"Shuang Tan , Francesco Dalena , Igor E. Golub , Eddy Dib , Oleg A. Filippov , Ludovica Pace , Rémy Guillet-Nicolas , Valentin Valtchev , Hailing Guo , Svetlana Mintova","doi":"10.1016/j.micromeso.2024.113347","DOIUrl":"10.1016/j.micromeso.2024.113347","url":null,"abstract":"<div><div>The incorporation of heteroatoms (X) into the zeolite-templated carbon (ZTC) structure is a widely used technique to tailor its properties for specific applications such as gas adsorption, methane and hydrogen storage, and catalysis. However, the literature lacks sufficient data on Fourier-transform infrared spectroscopy (FTIR) analysis of ZTCs due to the challenge in obtaining high-quality FTIR spectra required for accurate assignment of the C–X bands, primarily caused by the black mass effect. In this work we prepared nitrogen (N) and phosphorus (P) doped ZTC samples using FAU type zeolite as a template and furfuryl alcohol as a carbon precursor. The Raman results confirmed the presence of medium-sized aromatic structures and also showed that doping these structures with N and P leads to some defects, although the overall conformation remains structurally intact. The FTIR spectra of the ZTC materials were obtained by controlling the preparation procedure and humidity, enabling clear analysis of the black samples. A Density Functional Theory (DFT) model based on the dimeric buckybowl structure was developed and complemented by experimental results obtained from X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and FTIR. The proposed DFT model was then used for deconvolution and precise band assignment of the experimental FTIR spectra. The FTIR deconvolution study also supported the incorporation of N and P into the ZTC as well as the presence of primarily two types of nitrogen species, amide (primary and secondary) and pyridine-like, while P was mainly incorporated as triphenylphosphine oxide and phosphonic acid.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113347"},"PeriodicalIF":4.8,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323612","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}
This study investigates the effects of boron (B) and crucial interplay between NaOH and TPABr during the synthesis of seed-induced H-B-ZSM-5 for designing effective MTP catalysts. Various characterization techniques were employed to examine the impact of these factors on the physiochemical properties of the synthesized catalysts. The findings reveal that boron incorporation leads to an 81 % increase in catalyst stability and a 5.5 % increase in selectivity to light olefins. A critical interplay between NaOH concentration and TPABr content was also found in optimizing crystallinity, morphology, acidity and surface area. The crystallinity, Al distribution homogeneity, and average pore size initially increase before decreasing with increasing NaOH concentration. The research highlights the pivotal role of TPABr, which interacts with NaOH to profoundly impact catalyst performance. The synthesized catalyst H-B-ZSM-5, prepared with TPABr/20SiO2 = 0.65 and Na2O/20SiO2 = 1.69, exhibits excellent performance, achieving 99 % conversion and 83 % light olefin selectivity with minimal byproduct formation during a 170-h test at a high WHSVmethanol equal to 8 h−1.
{"title":"Optimizing H-B-ZSM-5 catalyst for efficient methanol-to-propylene conversion via precise control of NaOH-TPABr interaction","authors":"Marzieh Hamidzadeh , Mohadese Nazari , Solmaz Shifteh , Ali Abdolali","doi":"10.1016/j.micromeso.2024.113344","DOIUrl":"10.1016/j.micromeso.2024.113344","url":null,"abstract":"<div><div>This study investigates the effects of boron (B) and crucial interplay between NaOH and TPABr during the synthesis of seed-induced H-B-ZSM-5 for designing effective MTP catalysts. Various characterization techniques were employed to examine the impact of these factors on the physiochemical properties of the synthesized catalysts. The findings reveal that boron incorporation leads to an 81 % increase in catalyst stability and a 5.5 % increase in selectivity to light olefins. A critical interplay between NaOH concentration and TPABr content was also found in optimizing crystallinity, morphology, acidity and surface area. The crystallinity, Al distribution homogeneity, and average pore size initially increase before decreasing with increasing NaOH concentration. The research highlights the pivotal role of TPABr, which interacts with NaOH to profoundly impact catalyst performance. The synthesized catalyst H-B-ZSM-5, prepared with TPABr/20SiO<sub>2</sub> = 0.65 and Na<sub>2</sub>O/20SiO<sub>2</sub> = 1.69, exhibits excellent performance, achieving 99 % conversion and 83 % light olefin selectivity with minimal byproduct formation during a 170-h test at a high WHSV<sub>methanol</sub> equal to 8 h<sup>−1</sup>.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113344"},"PeriodicalIF":4.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318539","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 : 2024-09-21DOI: 10.1016/j.micromeso.2024.113346
Mohamed Bouzid , Lotfi Sellaoui , Mounir Ben El Hadj Rhouma , Adrian Bonilla-Petriciolet , Abdelmottaleb Ben Lamine
In this study, a modified advanced double-layer model based on statistical physics was developed and utilized to explore the adsorption of carbon dioxide (CO2) on two zeolites: W-ZSM-5 and W-silicalite-1. This model was formulated assuming that different chemical potentials were involved in the interfacial phenomenon, in contrast to other double-layer models that consider only one chemical potential. This formulation provides a better understanding of the multilayer adsorption of gases. The results obtained from this new model indicate that in the case of the CO2-W-ZSM-5 system, CO2 molecules altered their adsorption orientation from a mixed orientation (n = 0.88) involving both parallel and non-parallel configurations. Similarly, the molecules shifted from a multimolecular orientation (n = 1.17) to a perpendicular orientation for CO2 adsorption on the W-silicalite-1 surface. The calculated adsorption energies confirmed the presence of an exothermic adsorption process governed by physical interactions between the CO2 molecules and the surfaces of these zeolites. Finally, the adsorption energy distribution (AED) of both adsorbent surfaces was analyzed to determine the energy band activated during the CO2 capture process. These findings contribute to a deeper understanding of CO2 adsorption on zeolite surfaces. This new statistical physics model can be used for the process design of gas adsorption systems in various applications.
{"title":"Understanding the adsorption mechanism of carbon dioxide capture on hybrid zeolites prepared from rice husk ash via a modified statistical physics model","authors":"Mohamed Bouzid , Lotfi Sellaoui , Mounir Ben El Hadj Rhouma , Adrian Bonilla-Petriciolet , Abdelmottaleb Ben Lamine","doi":"10.1016/j.micromeso.2024.113346","DOIUrl":"10.1016/j.micromeso.2024.113346","url":null,"abstract":"<div><div>In this study, a modified advanced double-layer model based on statistical physics was developed and utilized to explore the adsorption of carbon dioxide (CO<sub>2</sub>) on two zeolites: W-ZSM-5 and W-silicalite-1. This model was formulated assuming that different chemical potentials were involved in the interfacial phenomenon, in contrast to other double-layer models that consider only one chemical potential. This formulation provides a better understanding of the multilayer adsorption of gases. The results obtained from this new model indicate that in the case of the CO<sub>2</sub>-W-ZSM-5 system, CO<sub>2</sub> molecules altered their adsorption orientation from a mixed orientation (n = 0.88) involving both parallel and non-parallel configurations. Similarly, the molecules shifted from a multimolecular orientation (n = 1.17) to a perpendicular orientation for CO<sub>2</sub> adsorption on the W-silicalite-1 surface. The calculated adsorption energies confirmed the presence of an exothermic adsorption process governed by physical interactions between the CO<sub>2</sub> molecules and the surfaces of these zeolites. Finally, the adsorption energy distribution (AED) of both adsorbent surfaces was analyzed to determine the energy band activated during the CO<sub>2</sub> capture process. These findings contribute to a deeper understanding of CO<sub>2</sub> adsorption on zeolite surfaces. This new statistical physics model can be used for the process design of gas adsorption systems in various applications.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"381 ","pages":"Article 113346"},"PeriodicalIF":4.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142310731","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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