Pub Date : 2025-03-05DOI: 10.1016/j.micromeso.2025.113579
Lei Fang , Shaoping Feng , Heping Yan , Na Wu , Gaozhang Gou
Covalent organic frameworks (COFs) provide considerable design flexibility concerning linkages and functional groups. By modulating the degree of conjugation, charge delocalization, and π-π stacking of COFs, promising photoluminescent materials can be developed. Here, we synthesized a series of 2D COFs containing aggregation-caused quenching (ACQ) groups (pyrene), and the fluorescence of the pyrene moiety was fine-tuned by varying the linkers (imine, olefin) and functional groups (‒OH, ‒OMe, ‒F). Compared to imine-based COFs, the olefin-linked COF (Olefin-COF-F) exhibited significantly enhanced photoluminescence, with ten times higher quantum efficiency than Imine-COF. Olefin-COF-F benefits from interlayer hydrogen bonding and can detect HCl via fluorescence turn-off behavior and showed fluorescence turn-on behavior in NaOH solutions. Coating blue light-emitting diodes with Olefin-COF-F resulted in a high-purity white-light device. This research offers valuable insights into the controlled synthesis of COF-based photoluminescent materials featuring ACQ groups.
{"title":"Synergistic regulation of photoluminescence in covalent organic frameworks by linkages and functional groups","authors":"Lei Fang , Shaoping Feng , Heping Yan , Na Wu , Gaozhang Gou","doi":"10.1016/j.micromeso.2025.113579","DOIUrl":"10.1016/j.micromeso.2025.113579","url":null,"abstract":"<div><div>Covalent organic frameworks (COFs) provide considerable design flexibility concerning linkages and functional groups. By modulating the degree of conjugation, charge delocalization, and π-π stacking of COFs, promising photoluminescent materials can be developed. Here, we synthesized a series of 2D COFs containing aggregation-caused quenching (ACQ) groups (pyrene), and the fluorescence of the pyrene moiety was fine-tuned by varying the linkers (imine, olefin) and functional groups (‒OH, ‒OMe, ‒F). Compared to imine-based COFs, the olefin-linked COF (Olefin-COF-F) exhibited significantly enhanced photoluminescence, with ten times higher quantum efficiency than Imine-COF. Olefin-COF-F benefits from interlayer hydrogen bonding and can detect HCl <em>via</em> fluorescence turn-off behavior and showed fluorescence turn-on behavior in NaOH solutions. Coating blue light-emitting diodes with Olefin-COF-F resulted in a high-purity white-light device. This research offers valuable insights into the controlled synthesis of COF-based photoluminescent materials featuring ACQ groups.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"390 ","pages":"Article 113579"},"PeriodicalIF":4.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579581","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 : 2025-03-04DOI: 10.1016/j.micromeso.2025.113577
Zehong Zhu , Qingxin Wu , Xueying Wang , Haiyang Zhang , Jian Li , Yanzhao Dong , Yongsheng Xu , Yunsheng Dai , Jinli Zhang
Here, the spiral mesoporous hydrothermal carbonaceous nanospheres (SMHNs) were designed and fabricated from pentose precursors to enhance gas diffusion in acetylene hydrochlorination. Through the optimization of hydrothermal conditions, the optimized SMCNs-800 material showcased the highest catalytic activity with an acetylene conversion of 77 % under the condition of GHSV (C2H2) = 30 h−1. The structural analysis indicated that the material with helical structure could provide larger pore sizes and abundant defect sites, exposing more active sites. The structure-activity relationship among acid-base properties of the catalyst surface, the adsorption-desorption capacity for the reactants and the catalytic activity jointly demonstrated that pyridine-N and -C=O could provide abundant basic sites for the adsorption and activation of H-Cl, thus accelerating the process of acetylene hydrochlorination reaction.
{"title":"Acetylene hydrochlorination catalyzed by N/O-doped spiral mesoporous carbonaceous nanospheres","authors":"Zehong Zhu , Qingxin Wu , Xueying Wang , Haiyang Zhang , Jian Li , Yanzhao Dong , Yongsheng Xu , Yunsheng Dai , Jinli Zhang","doi":"10.1016/j.micromeso.2025.113577","DOIUrl":"10.1016/j.micromeso.2025.113577","url":null,"abstract":"<div><div>Here, the spiral mesoporous hydrothermal carbonaceous nanospheres (SMHNs) were designed and fabricated from pentose precursors to enhance gas diffusion in acetylene hydrochlorination. Through the optimization of hydrothermal conditions, the optimized SMCNs-800 material showcased the highest catalytic activity with an acetylene conversion of 77 % under the condition of GHSV (C<sub>2</sub>H<sub>2</sub>) = 30 h<sup>−1</sup>. The structural analysis indicated that the material with helical structure could provide larger pore sizes and abundant defect sites, exposing more active sites. The structure-activity relationship among acid-base properties of the catalyst surface, the adsorption-desorption capacity for the reactants and the catalytic activity jointly demonstrated that pyridine-N and -C=O could provide abundant basic sites for the adsorption and activation of H-Cl, thus accelerating the process of acetylene hydrochlorination reaction.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"389 ","pages":"Article 113577"},"PeriodicalIF":4.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549142","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 : 2025-03-04DOI: 10.1016/j.micromeso.2025.113576
Taotao Lu , Hui Li , Yanping Zheng , Lei Shi , Rong Nie , Liang Zhao , Yanxing Qi
Pillar[5]arene, a novel class of pillar-shaped macrocyclic hosts, has demonstrated significant potential across diverse fields due to its symmetrical pillar-shaped structures, flexible functionalization, and unique host–guest interactions. Moreover, pillar[5]arene-based functional materials have garnered considerable interest owning to their unique topological and chemical structures, as well as their physicochemical properties. In this review, we discuss the exceptional properties of pillar[5]arene-based silicon materials. Specifically, we summarize the preparation of complex pillar[5]arene-based silicon materials and their applications in molecular recognition, chromatographic separation, adsorption and controllable release (including pH, electron, temperature, ions, gas, multiresponsive controlled release and osmotic release). Finally, we outline the future perspectives of pillar[5]arene chemistry. We anticipate that this review will serve as a valuable reference for researchers in the field and inspire new discoveries related to pillar[5]arene-based materials.
{"title":"Progress in pillar[5]arene-based silicon porous materials: From preparation to applications","authors":"Taotao Lu , Hui Li , Yanping Zheng , Lei Shi , Rong Nie , Liang Zhao , Yanxing Qi","doi":"10.1016/j.micromeso.2025.113576","DOIUrl":"10.1016/j.micromeso.2025.113576","url":null,"abstract":"<div><div>Pillar[5]arene, a novel class of pillar-shaped macrocyclic hosts, has demonstrated significant potential across diverse fields due to its symmetrical pillar-shaped structures, flexible functionalization, and unique host–guest interactions. Moreover, pillar[5]arene-based functional materials have garnered considerable interest owning to their unique topological and chemical structures, as well as their physicochemical properties. In this review, we discuss the exceptional properties of pillar[5]arene-based silicon materials. Specifically, we summarize the preparation of complex pillar[5]arene-based silicon materials and their applications in molecular recognition, chromatographic separation, adsorption and controllable release (including pH, electron, temperature, ions, gas, multiresponsive controlled release and osmotic release). Finally, we outline the future perspectives of pillar[5]arene chemistry. We anticipate that this review will serve as a valuable reference for researchers in the field and inspire new discoveries related to pillar[5]arene-based materials.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"389 ","pages":"Article 113576"},"PeriodicalIF":4.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549145","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 : 2025-03-04DOI: 10.1016/j.micromeso.2025.113571
Lin Lei , Jiaxian Chen , Jinhong Xiao , Yongjian Qiu , Qinggang Ren , Yaju Chen , Hongbing Ji
An imidazolium-based hyper-crosslinked porous ionic polymer (IHPiP) immobilized phosphotungstic (PW) anions hybrid catalyst (IHPiP-PW) was synthesized based on a one-pot Friedel–Crafts alkylation and quaternization reaction, followed by anion exchange. The obtained IHPiP-PW exhibited a high specific surface area of 615 m2 g−1 containing plentiful hierarchical pores. IHPiP-PW was effective in the oxidation of 1-phenylethanol into acetophenone with H2O2 to give a high conversion of 95.7 % and quantitative selectivity. A remarkable turnover number of 3300 and initial turnover frequency of 914.0 h−1 were obtained at a substrate/PW molar ratio of 4000. Kinetic study demonstrated that 1-phenylethanol oxidation obeyed pseudo-first-order kinetics and the apparent activation energy was calculated to be 26.116 kJ mol−1. This catalytic system was tolerant of a wide range of substrates. Moreover, IHPiP-PW could be readily recovered and effectively reused for six cycles without significant catalytic activity loss.
{"title":"Phosphotungstic anions-based imidazolium porous ionic polymer for oxidation of alcohols with hydrogen peroxide","authors":"Lin Lei , Jiaxian Chen , Jinhong Xiao , Yongjian Qiu , Qinggang Ren , Yaju Chen , Hongbing Ji","doi":"10.1016/j.micromeso.2025.113571","DOIUrl":"10.1016/j.micromeso.2025.113571","url":null,"abstract":"<div><div>An imidazolium-based hyper-crosslinked porous ionic polymer (IHPiP) immobilized phosphotungstic (PW) anions hybrid catalyst (IHPiP-PW) was synthesized based on a one-pot Friedel–Crafts alkylation and quaternization reaction, followed by anion exchange. The obtained IHPiP-PW exhibited a high specific surface area of 615 m<sup>2</sup> g<sup>−1</sup> containing plentiful hierarchical pores. IHPiP-PW was effective in the oxidation of 1-phenylethanol into acetophenone with H<sub>2</sub>O<sub>2</sub> to give a high conversion of 95.7 % and quantitative selectivity. A remarkable turnover number of 3300 and initial turnover frequency of 914.0 h<sup>−1</sup> were obtained at a substrate/PW molar ratio of 4000. Kinetic study demonstrated that 1-phenylethanol oxidation obeyed pseudo-first-order kinetics and the apparent activation energy was calculated to be 26.116 kJ mol<sup>−1</sup>. This catalytic system was tolerant of a wide range of substrates. Moreover, IHPiP-PW could be readily recovered and effectively reused for six cycles without significant catalytic activity loss.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"390 ","pages":"Article 113571"},"PeriodicalIF":4.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562202","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 : 2025-03-04DOI: 10.1016/j.micromeso.2025.113578
Alshaima Sayed , Ahmed M. El-Sherbeeny , Gouda Ismail Abdel-Gawad , Wail Al Zoubi , Essam A. Mohamed , Mostafa R. Abukhadra
Three varieties of calcium-bearing mesoporous silica (MCM-41) were synthesized using different types of natural calcium carbonate precursors (limestone (L.MCM), coral reefs (C.MCM), and marble (M.MCM). The different varieties were characterized by different analytic techniques confirming their formation as Ca-MCM-41 with mesoporous properties and possessing different morphologies. They were applied in adsorption studies for sulfate ions, achieving saturation capacities of 135.9 mg/g (L MCM), 167.9 mg/g (C MCM), and 141 mg/g (M MCM). The better performance of C.MCM than the other forms is in agreement with its morphological aspects and its enhanced surface area (159.6 m2/g) in addition to the supporting theoretical findings. Modeling the uptake process based on the concepts and parameters of statistical physics declared enrichment of C.MCM surface with a higher density of active sites (Nm = 86.5 mg/g) as compared to L.MCM (64.7 mg/g) and 68.14 mg/g (M MCM). Each of these sites can accommodate up to 3 sulfate ions, donating the impact of multi-ionic interactions mechanisms in addition to their adsorption in parallel and vertical orientations. Energetic and thermodynamic assessment implies uptake of sulfate by exothermic reactions of spontaneous behaviors displaying uptake energy less than 8 kJ/mol. This energetic level corresponds to the physical adsorption mechanisms, including hydrogen bonding and van der Waals forces. The C.MCM structure (1.2 g/L) was applied effectively in realistic sequestration of sulfate from seawater along the Gulf of Suez, reducing its content (2614 mg/L) by about 42 %, adsorbing about 1103 mg of sulfate ions.
{"title":"Synthesis and characterization of series of Ca-MCM-41 nanoporous structures for effective elimination of sulfate ions; insight into the used calcium precursor and realistic studies","authors":"Alshaima Sayed , Ahmed M. El-Sherbeeny , Gouda Ismail Abdel-Gawad , Wail Al Zoubi , Essam A. Mohamed , Mostafa R. Abukhadra","doi":"10.1016/j.micromeso.2025.113578","DOIUrl":"10.1016/j.micromeso.2025.113578","url":null,"abstract":"<div><div>Three varieties of calcium-bearing mesoporous silica (MCM-41) were synthesized using different types of natural calcium carbonate precursors (limestone (L.MCM), coral reefs (C.MCM), and marble (M.MCM). The different varieties were characterized by different analytic techniques confirming their formation as Ca-MCM-41 with mesoporous properties and possessing different morphologies. They were applied in adsorption studies for sulfate ions, achieving saturation capacities of 135.9 mg/g (L MCM), 167.9 mg/g (C MCM), and 141 mg/g (M MCM). The better performance of C.MCM than the other forms is in agreement with its morphological aspects and its enhanced surface area (159.6 m<sup>2</sup>/g) in addition to the supporting theoretical findings. Modeling the uptake process based on the concepts and parameters of statistical physics declared enrichment of C.MCM surface with a higher density of active sites (Nm = 86.5 mg/g) as compared to L.MCM (64.7 mg/g) and 68.14 mg/g (M MCM). Each of these sites can accommodate up to 3 sulfate ions, donating the impact of multi-ionic interactions mechanisms in addition to their adsorption in parallel and vertical orientations. Energetic and thermodynamic assessment implies uptake of sulfate by exothermic reactions of spontaneous behaviors displaying uptake energy less than 8 kJ/mol. This energetic level corresponds to the physical adsorption mechanisms, including hydrogen bonding and van der Waals forces. The C.MCM structure (1.2 g/L) was applied effectively in realistic sequestration of sulfate from seawater along the Gulf of Suez, reducing its content (2614 mg/L) by about 42 %, adsorbing about 1103 mg of sulfate ions.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"390 ","pages":"Article 113578"},"PeriodicalIF":4.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579095","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 : 2025-03-01DOI: 10.1016/j.micromeso.2025.113572
Shaoqing Jin, Qiangqiang Luo, Xueyan Fan, Hongmin Sun, Weimin Yang
Although Ti-MWW zeolite has received lots of attention due to its superior catalytic oxidation performance, it's still challenging to obtain boron-free Ti-MWW zeolite with few defects and high catalytic performance by a simple way. Herein, secondary acid treatment was utilized to modify the structure of Ti-MWW zeolite and its catalytic behavior. It was found that almost all the framework boron atoms could be removed by secondary acid treatment under different conditions. However, different from secondary acid treatment under low-temperature & high-acid concentration (LTHC) condition, that under high-temperature & low-acid concentration (HTLC) condition can heal the silanol nests originally existing and formed during boron removal through silicon migration, remarkably improving the hydrophobicity, the micro-environment of framework TiO4 species (Fw-TiO4) and thus the catalytic activity in 1-hexene epoxidation in spite of a certain amount of inactive anatase TiO2 species formed. This study would be helpful for the post modification and understanding of Ti-MWW zeolite.
{"title":"Effect of secondary acid treatment on the structure of Ti-MWW zeolite and its catalytic performance","authors":"Shaoqing Jin, Qiangqiang Luo, Xueyan Fan, Hongmin Sun, Weimin Yang","doi":"10.1016/j.micromeso.2025.113572","DOIUrl":"10.1016/j.micromeso.2025.113572","url":null,"abstract":"<div><div>Although Ti-MWW zeolite has received lots of attention due to its superior catalytic oxidation performance, it's still challenging to obtain boron-free Ti-MWW zeolite with few defects and high catalytic performance by a simple way. Herein, secondary acid treatment was utilized to modify the structure of Ti-MWW zeolite and its catalytic behavior. It was found that almost all the framework boron atoms could be removed by secondary acid treatment under different conditions. However, different from secondary acid treatment under low-temperature & high-acid concentration (LTHC) condition, that under high-temperature & low-acid concentration (HTLC) condition can heal the silanol nests originally existing and formed during boron removal through silicon migration, remarkably improving the hydrophobicity, the micro-environment of framework TiO<sub>4</sub> species (Fw-TiO<sub>4</sub>) and thus the catalytic activity in 1-hexene epoxidation in spite of a certain amount of inactive anatase TiO<sub>2</sub> species formed. This study would be helpful for the post modification and understanding of Ti-MWW zeolite.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"389 ","pages":"Article 113572"},"PeriodicalIF":4.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549144","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 : 2025-03-01DOI: 10.1016/j.micromeso.2025.113573
Su-Un Lee , Jun-Hyuk Ahn , Wang-Geun Shim , Sungjune Lee , Kwang-Eun Jeong , Su Ah Kang , Chul-Ung Kim , Jeong-Chul Kim , Tae-Wan Kim
The particle size of SSZ-13 zeolites, while maintaining a consistent cubic shape and uniform Si/Al2 ratios, was successfully controlled from 100 nm to 900 nm via seed-assisted interzeolite conversion of Y zeolites in the presence of TMAdaOH and NaOH. Despite the consistent Si/Al2 ratio, variations in particle size induced significant changes in acidic properties, attributed to alterations in the coordination of aluminum species on the zeolite surface. Specifically, smaller particle sizes and spherical morphology resulted in reduced acidity, particularly at the strong acid sites. Propane equilibrium isotherms also revealed that the modifications of particle size and the associated acidity substantially influence the diffusion and residence time of reactants and products. In ethylene-to-propylene (ETP) reactions, smaller particle sizes in cubic SSZ-13 enhanced diffusion and reduced acidity, minimizing undesirable successive reactions and increasing propylene selectivity. However, excessive diffusion and weaker acidity caused the premature escape of intermediates, demonstrating a volcano-type relationship between particle size and catalytic efficiency. Notably, 250 nm-cubic SSZ-13 achieved an optimal balance of diffusion and acidity via size and shape control, leading to slower deactivation, higher propylene selectivity, and greater propylene yield. These findings provide valuable insights into the interplay between morphological modifications, physicochemical properties, and catalytic performance, offering a foundation for advancing the design of catalytic materials.
{"title":"Impact of modified acidity and diffusion on ethylene-to-propylene reaction via size and shape controlled SSZ-13 zeolite","authors":"Su-Un Lee , Jun-Hyuk Ahn , Wang-Geun Shim , Sungjune Lee , Kwang-Eun Jeong , Su Ah Kang , Chul-Ung Kim , Jeong-Chul Kim , Tae-Wan Kim","doi":"10.1016/j.micromeso.2025.113573","DOIUrl":"10.1016/j.micromeso.2025.113573","url":null,"abstract":"<div><div>The particle size of SSZ-13 zeolites, while maintaining a consistent cubic shape and uniform Si/Al<sub>2</sub> ratios, was successfully controlled from 100 nm to 900 nm via seed-assisted interzeolite conversion of Y zeolites in the presence of TMAdaOH and NaOH. Despite the consistent Si/Al<sub>2</sub> ratio, variations in particle size induced significant changes in acidic properties, attributed to alterations in the coordination of aluminum species on the zeolite surface. Specifically, smaller particle sizes and spherical morphology resulted in reduced acidity, particularly at the strong acid sites. Propane equilibrium isotherms also revealed that the modifications of particle size and the associated acidity substantially influence the diffusion and residence time of reactants and products. In ethylene-to-propylene (ETP) reactions, smaller particle sizes in cubic SSZ-13 enhanced diffusion and reduced acidity, minimizing undesirable successive reactions and increasing propylene selectivity. However, excessive diffusion and weaker acidity caused the premature escape of intermediates, demonstrating a volcano-type relationship between particle size and catalytic efficiency. Notably, 250 nm-cubic SSZ-13 achieved an optimal balance of diffusion and acidity via size and shape control, leading to slower deactivation, higher propylene selectivity, and greater propylene yield. These findings provide valuable insights into the interplay between morphological modifications, physicochemical properties, and catalytic performance, offering a foundation for advancing the design of catalytic materials.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"390 ","pages":"Article 113573"},"PeriodicalIF":4.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579580","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 : 2025-03-01DOI: 10.1016/j.micromeso.2025.113574
Elen Maria Feliciano Pereira , Alejandro Lopez-Castillo , Leandro Martins
The activity of the chabazite zeolite in the Methanol to Olefins (MTO) reaction is tightly connected to the organic intermediates confined in its pores. The intermediates and the pores of near dimensions construct a reciprocal reaction environment for the MTO, known as the hydrocarbon pool (HP) mechanism. The chabazite structure (CHA) stands out in MTO due to the three-dimensional system of large pores connected by small openings, allowing the confinement of the intermediates, allowing small olefins to diffuse in and out. Herein, the organic intermediates in the HP arose as soon as the CHA catalyst was subjected to reaction temperature under a methanol flow. HP was identified to be composed of bridged-ring alkanes (at very low temperatures) and polyaromatics of up to five rings, which grew throughout the reaction, leading to the deactivation of the catalyst. The most active species are the least polymeric. The systematic increase in reaction temperature from 190 to 450 °C revealed a combined change of the zeolite's crystalline structure, which elongates into the c-direction, while olefins are formed. DFT computational simulations confirmed confinement is a spontaneous process forming a hybrid organic-inorganic environment active in the MTO reaction. Other DFT results expanded the understanding of the molecular confinement related to interaction energies with and without system deformation in obtaining geometric parameters beyond the experimental resolution.
{"title":"Evolution of active intermediates in MTO reaction on a Chabazite catalyst","authors":"Elen Maria Feliciano Pereira , Alejandro Lopez-Castillo , Leandro Martins","doi":"10.1016/j.micromeso.2025.113574","DOIUrl":"10.1016/j.micromeso.2025.113574","url":null,"abstract":"<div><div>The activity of the chabazite zeolite in the Methanol to Olefins (MTO) reaction is tightly connected to the organic intermediates confined in its pores. The intermediates and the pores of near dimensions construct a reciprocal reaction environment for the MTO, known as the hydrocarbon pool (HP) mechanism. The chabazite structure (CHA) stands out in MTO due to the three-dimensional system of large pores connected by small openings, allowing the confinement of the intermediates, allowing small olefins to diffuse in and out. Herein, the organic intermediates in the HP arose as soon as the CHA catalyst was subjected to reaction temperature under a methanol flow. HP was identified to be composed of bridged-ring alkanes (at very low temperatures) and polyaromatics of up to five rings, which grew throughout the reaction, leading to the deactivation of the catalyst. The most active species are the least polymeric. The systematic increase in reaction temperature from 190 to 450 °C revealed a combined change of the zeolite's crystalline structure, which elongates into the c-direction, while olefins are formed. DFT computational simulations confirmed confinement is a spontaneous process forming a hybrid organic-inorganic environment active in the MTO reaction. Other DFT results expanded the understanding of the molecular confinement related to interaction energies with and without system deformation in obtaining geometric parameters beyond the experimental resolution.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"389 ","pages":"Article 113574"},"PeriodicalIF":4.8,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549143","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 : 2025-02-28DOI: 10.1016/j.micromeso.2025.113570
Haoyan Zhou , Mei Zu , Shiquan Li , Yuanxi Chang , Chenglong Lv , Haifeng Cheng
The development of materials that simulate the visible and near-infrared (Vis-NIR) spectral characteristics of vegetation is crucial in the field of biomimetic camouflage. In this research, a novel spectral simulation material based on ion-exchanged zeolites has been synthesized, designed to simulate the spectral characteristics of green and yellow foliage. The structure and microscopic morphology of ion-exchanged zeolite was checked by XRD, FTIR, SEM techniques. Also, N2 physisorption analyses and UV–Vis–NIR spectroscopy were use to analyzed the effect of ion exchange concentration on its water vapor adsorption capacity and spectral reflectance. The introduction of metal cations can mimic the absorption of different pigments in visible bands in plant leaves. Meanwhile, the analysis shows that exchange with chromium and iron cations resulted in a maximum increase in specific surface area to 604 and 582 m2/g, respectively, and consequently the increase in water adsorption capacity with approximately the same rate (13.1 %, 9.3 %), which further enhances the similarity of the near-infrared spectra. Subsequently, bionic coatings were prepared using ion-exchanged zeolites as pigments, and the spectral correlation coefficient of the Vis-NIR spectrum between bionic coatings and green and yellow leaves reached 0.95 and 0.96, which effectively solved the problem of accurately simulating the same color and spectrum as vegetation in the 400–2500 nm wavelength range.
{"title":"Ion-exchanged zeolite for simulating the Vis-NIR spectra characteristics of natural leaves","authors":"Haoyan Zhou , Mei Zu , Shiquan Li , Yuanxi Chang , Chenglong Lv , Haifeng Cheng","doi":"10.1016/j.micromeso.2025.113570","DOIUrl":"10.1016/j.micromeso.2025.113570","url":null,"abstract":"<div><div>The development of materials that simulate the visible and near-infrared (Vis-NIR) spectral characteristics of vegetation is crucial in the field of biomimetic camouflage. In this research, a novel spectral simulation material based on ion-exchanged zeolites has been synthesized, designed to simulate the spectral characteristics of green and yellow foliage. The structure and microscopic morphology of ion-exchanged zeolite was checked by XRD, FTIR, SEM techniques. Also, N<sub>2</sub> physisorption analyses and UV–Vis–NIR spectroscopy were use to analyzed the effect of ion exchange concentration on its water vapor adsorption capacity and spectral reflectance. The introduction of metal cations can mimic the absorption of different pigments in visible bands in plant leaves. Meanwhile, the analysis shows that exchange with chromium and iron cations resulted in a maximum increase in specific surface area to 604 and 582 m<sup>2</sup>/g, respectively, and consequently the increase in water adsorption capacity with approximately the same rate (13.1 %, 9.3 %), which further enhances the similarity of the near-infrared spectra. Subsequently, bionic coatings were prepared using ion-exchanged zeolites as pigments, and the spectral correlation coefficient of the Vis-NIR spectrum between bionic coatings and green and yellow leaves reached 0.95 and 0.96, which effectively solved the problem of accurately simulating the same color and spectrum as vegetation in the 400–2500 nm wavelength range.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"390 ","pages":"Article 113570"},"PeriodicalIF":4.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552478","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 : 2025-02-27DOI: 10.1016/j.micromeso.2025.113560
Tian Zhao, Fuli Luo, Pengcheng Xiao, Saiqun Nie, Jiayao Chen, Yi Chen
This review systematically explores the application and research progress of metal-organic frameworks (MOFs) based composites in electrocatalysis. Firstly, we introduce a variety of preparation methods for MOFs-based composites, including in situ doping/substitution, hydrothermal/solvent-thermal methods, solution impregnation, dual-solvent impregnation, and sandwich assembly, with a focus on analyzing the effects of different methods on the structure and properties of the materials. Secondly, the practical applications of MOFs-based composites in electrocatalytic reactions, including hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, nitrogen reduction reaction, and carbon dioxide reduction, are elaborated in detail, with emphasis on their excellent properties and catalytic mechanisms. Finally, we look forward to the future development trend of MOFs-based composites, and believe that with the emergence of novel synthesis technologies and idealized design methods, MOFs-based composites will show greater potential for applications in areas such as renewable energy conversion and environmental governance. In summary, this review provides a comprehensive perspective and in-depth analysis of the electrocatalytic studies of MOFs-based composites.
{"title":"Strategies for the preparation of MOFs-based composites and their research progress in electrocatalysis","authors":"Tian Zhao, Fuli Luo, Pengcheng Xiao, Saiqun Nie, Jiayao Chen, Yi Chen","doi":"10.1016/j.micromeso.2025.113560","DOIUrl":"10.1016/j.micromeso.2025.113560","url":null,"abstract":"<div><div>This review systematically explores the application and research progress of metal-organic frameworks (MOFs) based composites in electrocatalysis. Firstly, we introduce a variety of preparation methods for MOFs-based composites, including in situ doping/substitution, hydrothermal/solvent-thermal methods, solution impregnation, dual-solvent impregnation, and sandwich assembly, with a focus on analyzing the effects of different methods on the structure and properties of the materials. Secondly, the practical applications of MOFs-based composites in electrocatalytic reactions, including hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, nitrogen reduction reaction, and carbon dioxide reduction, are elaborated in detail, with emphasis on their excellent properties and catalytic mechanisms. Finally, we look forward to the future development trend of MOFs-based composites, and believe that with the emergence of novel synthesis technologies and idealized design methods, MOFs-based composites will show greater potential for applications in areas such as renewable energy conversion and environmental governance. In summary, this review provides a comprehensive perspective and in-depth analysis of the electrocatalytic studies of MOFs-based composites.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"389 ","pages":"Article 113560"},"PeriodicalIF":4.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529013","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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