RSC Advances
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2025
·Vol. 15
·期 11
·8696-8706
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IF 4.6
Zijian Wang,Ming Ke,Zhaozheng Song
Mordenite is extensively utilized in the domains of adsorption and catalysis owing to its excellent selectivity, stability, and renewability. In this work, the effects of crystal seeds, the ratio of SiO2/Al2O3, crystallization temperature, silicon source, and structure directing agents on the morphologies of mordenite are investigated by utilizing hexamethyleneimine (HMI) as the OSDA. Results indicate that the transformation of rod-like and flake-like mordenites is mainly related to the increasing ratio of SiO2/Al2O3, and the formation of flake-like morphology is related to various conditions. On a macro level, the rod-like and flake-like zeolites are formed by transforming amorphous precursors into small crystals and growing them epitaxially. On a micro level, HMIH+ progressively displaces Na+ to balance the framework charge with the increasing ratio of SiO2/Al2O3. DFT calculation and nuclear magnetic resonance results confirm the specific guidance of HMI on the T2 and T4 sites of the rod-like and flake-like mordenites. The conclusion can serve as a reference for regulating the morphology and active sites of mordenite.
研究领域:
材料科学
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催化与吸附领域
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Lin Hu,Jingcheng Wu,Xian-Yong Wei,Changlin Yu,Lei Li,Lingling Li
Exploring the value-added utilization of lignin showed the great significant to realize the efficient conversion of lignocellulosic biomass, which had good environmental, economic, and social benefits. However, the catalytic hydrogenolysis of lignin faced the great problems, including harsh reaction conditions and low product yield. In this research, the FeOx modified Ru/mordenite (M) was synthesized by deposition–precipitation method and strengthened the effective lignin conversion process. Ru 2.5% Fe 2.5% /M showed the high catalytic hydrogenolysis activity of β-O-4 and α-O-4 bond under the condition of 260 °C, 1 MPa H 2 , and 3 h in the methanol. Though the research about reaction of model compounds and several characterizations, synergistic action of highly dispersion RuFe nanoparticles and acidic sites significantly promoted the breakage of C-O bond. The introduction of Fe species can reduced the size of metal nanoparticles. The lignin oil reached the high value of 47.8 wt%, and contained the low RC value of phenolic compounds. Finally, the reaction mechanism of lignin catalytic hydrogenolysis was discussed, and it found that the highly dispersed RuFe nanoparticles enhanced the synergistic transfer ability of H 2 and methanol to release H•. This research would give some useful understandings for the efficient thermochemical conversion of lignin.
研究领域:
催化化学
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生物质能
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环境科学
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DOI
高影响因子
Science China-Materials
·
2018
·Vol. 61
·期 9
·1185-1190
·
IF 4.318
Xu Yi,Shen Xuefeng,Peng Cheng,Ma Yue,Han Lu,Wu Peng,Peng Honggen,Che Shunai
The mordenite (MOR) nanoparticles (MNPs) with ultra-small crystallites (∼30 nm) were synthesized by using tetraethylammonium bromide (TEAB) as structure directing agent at low temperature (403 K). The formation of MNPs was considered to be due to high concentration of TEAB and occurrence of limiting Ostwald ripening at low temperature. The MNPs exhibited not only higher catalytic activity at low temperature for selective catalytic reduction of NO x but also higher catalytic activity and longer lifetime for disproportionation of toluene than conventional MOR (c-MOR) bulk crystals.
研究领域:
材料科学
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催化化学
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纳米技术
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无机化学
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DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-10
·
IF 15.7
Tang Xuan,Bai Xiaowei,Wang Yating,Li Xiaomin,Zhang Feifei,Wang Li,Wang Xiaoqing,Li Jinping,Yang Jiangfeng
Achieving low-energy and high-efficiency sieving of nitrogen rejection from methane in natural gas purification processes requires precise control of material pore size with a resolution of 0.1–0.2 Å, which is highly challenging. Here, we report a novel adsorbent (MOR-Cu), a mordenite with copper introduced in situ via high-temperature crystallization, enabling precise sieving of nitrogen and methane by the appropriate pore size and pore geometry. Refinement of the crystal structure shows that the higher crystallization temperature changes the position of the copper component, increasing pore volume and enhancing nitrogen adsorption capacity and kinetics. MOR-Cu-210 obtained by crystallization at 210 °C exhibits a record nitrogen adsorption capacity (0.74 mmol g –1 ) and nitrogen/methane uptake ratio (62.1) at 298 K and 1 bar, breaking the bottleneck of adsorption capacity and selectivity. Cyclic gas adsorption tests and column breakthrough experiments confirm high separation performance and stable recyclability.
研究领域:
材料科学
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化学工程
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吸附技术
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气体分离
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无机合成
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产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2020
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IF 0
Pei He,Ying Li,Kai Cai,Xiong Xiong,Jing Lv,Yue Wang,Shouying Huang,Xinbin Ma
Morphology dependent catalytic performance has been reported pervasively in heterogeneous catalysis, especially on nano-materials. Microporous zeolites with different shapes and sizes tend to exhibit distinct features in reactions, mainly resulting from varied diffusion limitations. Nano-sized zeolites are considered as great catalyst candidates because of a shorter diffusion path. However, design and fabrication of zeolite with nano dimensions and desired morphology are still challenging. Here, we elucidate the pathway(s) of mordenite (MOR) zeolite growth, which involves both particle attachment and layer-by-layer mechanisms. Then, we report a facile method to tune the morphology of MOR by adding cetyltrimethylammonium bromide (CTAB) during conventional hydrothermal synthesis. By combining TG-DTG, ICP-OES, acidic sites quantification, and a DFT study, we disclose that CTAB functions as a growth modifier as well as a pore filler during crystallization. As a result, the nanosheets-assembled, bundles-like, and flowers-like MOR are successfully synthesized, respectively. More importantly, the obtained MOR samples with CTAB addition show enhanced activity in carbonylation of dimethyl ether because of improved mass transfer efficiency. The results of this study offer a commercially available strategy to achieve required structural outcomes and optimize performance for microporous zeolites.
研究领域:
催化化学
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材料科学
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纳米技术
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多相催化
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微孔材料
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DOI
FUEL
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2024
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IF 6.7
Peng Lu,Wenjia Yu,Kui Wang,Xiaotong Wu,Wanting Zhang,Chuang Xing,Qinhong Wei,Yanhong Wang,Ce Du
A series of mordenite zeolites were prepared by a simple acid treatment in the presence and absence of templates for dimethyl ether carbonylation to methyl acetate. The structure and acidity of the prepared catalysts were characterized by XRD, BET, SEM, NH 3 -TPD, FTIR and TG. The nitric acid treatment mainly removed non-framework Al atoms in zeolites, thereby improving the crystallinity of samples, which was also protected by the template. Also, the specific surface area and mass transfer were improved due to the increase in porous structure and surface roughness. Furthermore, compared to 8-MR, the Brønsted acid sites in 12-MR can be reduced to a greater extent. And the protective effect of template molecules on the Al atom can maintain a relatively high level of Brønsted acid sites in mordenite. The relatively high Brønsted acid sites in 8-MR served as active sites. Meanwhile, the significant reduction of Brønsted acid content within 12-MR effectively inhibited carbon accumulation and improved the stability of the carbonylation reaction. M-0.1 exhibited the best catalytic performance, with DME conversion rate and MA selectivity of 72.75% and 96.14%, respectively. Therefore, retention of the organic template during acid treatment is an effective approach to improve the carbonylation activity.
研究领域:
化学工程
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催化材料
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产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2022
·Vol. 96
·期 12
·2747-2756
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IF 0.791
Li Xixi,Lu Xinhuan,Jing Run,Zhang Haifu,Wang Chenlong,Zhang Huaxin,Wang Beibei,Zhou Dan,Xia Qinghua
Abstract The MOR supported cobalt complex materials were synthesized by ion exchange method and used to catalyze the epoxidation reaction of α-pinene with air. The liquid phase batch mode of epoxidation reaction was carried out under atmospheric pressure and aerobic conditions. Among the supported [Co(NH 3 ) 6 ] 3+ -zeolites catalysts, [Co(NH 3 ) 6 ] 3+ -MOR exhibited the best catalytic efficiency for the titled reaction, and high reaction conversion as well as epoxidation product selectivity were obtained for α-pinene and α-epoxypinane. Parametric studies were performed to examine the effect factors like the Co content, the solvent, the initiator, the substrate amount and the catalyst amount. The catalyst can be reused at least nine cycles without significant loss in activity towards epoxidation.
研究领域:
化学工程
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催化材料
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DOI
高影响因子
Materials
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2024
·Vol. 17
·期 4
·854
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IF 3.1
Peixuan Lin,Song Ye,Ling Pan,Ruihao Huang,Haoran Zhang,Deping Wang
In this research, upconversion nanocrystals incorporated with MOR zeolite composites were synthesized using the desilicated MOR zeolite as a host for the in situ growth of NaREF4(RE = Y, Gd) Yb/Er nanocrystals. The structure and morphology of the composites were studied with XRD, XPS, and TEM measurements, and the spectral studies indicated that the subsequent thermal treatment can effectively improve the upconversion emission intensity of Er3+. By using the NaYF4:Yb/[email protected]composite that holds the strongest upconversion emission, a probe of UCNC@DSiMOR/BPEI was constructed with the modification of branched poly ethylenimine for the detection of Cu2+. It was indicated that the integrated emission intensity of Er3+shows a linear dependence with the logarithm value of the Cu2+concentration ranging from 0.1 to 10 μM. This study offered a feasible method for the construction of UCNC@zeolite composites with enhanced upconversion emission, which may have a potential application as fluorescent probes for the detection of various metal ions by adjusting the doping luminescent center.
研究领域:
材料科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry Letters
·
2021
·
IF 6.475
Ke Gong,Zhengmao Liu,Lixin Liang,Zhenchao Zhao,Meiling Guo,Xuebin Liu,Xiuwen Han,Xinhe Bao,Guangjin Hou
Herein, utilizing acetonitrile as the probe molecule, the acidity and host–guest interactions of H-mordenite (H-MOR) zeolites are investigated comprehensively by solid-state NMR spectroscopy and theoretical calculation. The locations and local configurations of Brønsted acid sites (BASs) in H-MOR are revealed by multinuclear and multidimensional NMR experiments with adsorption/coadsorption of acetonitrile (CD3CN) and trimethylphosphine (TMP). Moreover, the confinement effect of dual pores in MOR has been characterized via the quantitative determination of host–guest interactions between CH3CN and BASs. The 1H–15N dipolar measurement results and DFT calculations demonstrate that there are two kinds of acetonitrile molecules adsorbed in 12-membered ring (12MR) main channels with distinct mobility, where acetonitrile undergoes either partially restricted or highly flexible motion in the time scale of nanoseconds to microseconds. These two types of acetonitrile can exchange with temperature rising. In contrast, the mobility of acetonitrile in 8-membered ring (8MR) channels is very restricted due to the confinement of the framework.
研究领域:
材料科学
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催化化学
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物理化学
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固体核磁共振波谱学
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沸石化学
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2015
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IF 2.337
Jianlin Zhang,Yaming Mao,Jing Li,Xiaochen Wang,Jingyan Xie,Yu Zhou,Jun Wang
Micro-macroporous hierarchical mordenite (MOR topology) zeolitic monoliths with ultrahigh mechanical stability (crushing strength: 38 MPa) were directly prepared by the one-pot hydrothermal synthesis involving an unconventional acidic hydrolysis route. The obtained monolith exhibited highly crystallized MOR structure with the surface area of 388 m 2 g −1 and pore volume of 0.2 cm 3 g −1 , same as its powder analog. Moreover, it is the first example of binder-free hierarchical zeolites with the high mechanical strength comparable to industrially available binder-shaped counterparts. The micro-shape of primary particles and macro-shape of monoliths could be controlled by varying the elemental synthetic conditions. The synthesis is an efficient, sustainable and environmentally friendly approach because it avoids the employment of sacrificial templates, binders and high-temperature calcination , not only saving energy and time, but also inhibiting waste release. Also importantly, the MOR monolith could be directly used as the shaped catalyst without additional post-mold treatments. Catalytic tests in solvent-free Friedel–Crafts benzylation reaction of benzene with benzyl alcohol showed that the MOR monolith was much more active than its powder and binder-shaped control catalysts.
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DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 7
·1049
·
IF 3.9
Chenchen Dong,Yunduo Liu,Yumeng Xia,Hu Liu,Yan Zhang,Shouying Huang,Xinbin Ma
The carbonylation of dimethyl ether (DME) to produce methyl acetate (MA) has a promising prospect in industry. Mordenite (MOR) has been widely studied due to its excellent catalytic activity and high MA selectivity; however, its microporous characteristic limits the intracrystalline diffusion that influences the activity and stability. Therefore, it becomes essential to clarify the relationship between catalytic activity and diffusion. In this study, a series of MOR samples with similar Si/Al contents and aspect ratios, but different sizes, were successfully synthesized by adjusting the synthesis parameters (Si/Al contents in gel, aging time, the amount of water, and alkalinity). Based on quantitative analysis of acid properties and catalyst evaluation, both the apparent turnover frequency of MA (TOFMA) and the stability decrease with the increase in particle size. Diffusion parameter measurements and kinetic analysis via zero length column methods show that the intracrystalline diffusion restriction becomes more serious with increasing particle size. The larger the MOR crystals with enhanced mass transfer limitation that undergo lower activity, the higher the selectivity of byproducts, as well as the faster their deactivation.Keywords:dimethyl ether;carbonylation;mordenite;size effect;diffusion limitation
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2022
·
IF 6.562
Yumeng Xia,Zehua Li,Ying Li,Kai Cai,Yunduo Liu,Jing Lv,Shouying Huang,Xinbin Ma
Dimethyl ether (DME) carbonylation is an important reaction for methyl acetate (MA) and ethanol production from syngas. Mordenite (MOR) has been used as an industrial catalyst due to the competitive catalytic properties, especially with extremely high selectivity of MA (>99%). Given the Brønsted acid sites (BAS) in 8-MR are proved the active centers, the properties of BAS are crucial factors that influence the reaction. Until now, most of the researches focus on increasing the number of BAS rather than tuning the acid strength. Here we modified H-MOR by Ga introduction using incipient wetness impregnation. Catalyst evaluation results suggest that Ga species can enhance DME conversion with a maintained MA selectivity. Combining with characterizations and DFT calculation, the textural and acidic properties along with the existing form of Ga species are determined. Further in-situ IR, theoretical and kinetics investigations demonstrated that the enhanced acid strength accelerates the reaction on Ga-modified MOR catalysts. This work inspires us that improving the acid strength is an efficient strategy for Brønsted acid-catalyzed reaction, such as DME carbonylation .
研究领域:
催化化学
·
理论计算化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）