CATALYSIS TODAY
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2024
·
IF 5.2
Longyu Wang,Na Wang,Suohe Yang,Guangxiang He,Haiyan Liu,Xianghai Meng,Chunming Xu,Zhichang Liu,Haibo Jin
A diverse suite of Zn-SAPO-34 catalysts was synthesized employing three distinct methodologies for the incorporation of zinc species: thermal ion exchange, wet impregnation, and physical mixing. The catalysts were characterized using various analytical techniques including XRD, FT-IR, BET, SEM, XRF, XPS, NH 3 -TPD, and Py-IR, to elucidate the crystal structure, morphology, surface acidity, and the presence of zinc species within the catalysts. The study showed that the method of zinc introduction markedly impacts the physicochemical properties of the catalysts. Different approaches to introducing zinc species significantly influence the acid strength and type on the catalyst surface, with variations in the existing states of zinc across the catalysts. Specifically, zinc species introduced via thermal ion exchange coexist as ZnOH + and ZnO within the catalyst, whereas those from wet impregnation and physical mixing are individually present as either ZnOH + or ZnO. Furthermore, the study examined the catalytic performance of these Zn-SAPO-34 catalysts in the dehydration of fructose to produce 5-hydroxymethylfurfural (HMF). Catalysts prepared via thermal ion exchange exhinited superior performance, achieving an remarkable HMF yield of 94.6 %. Additionally, in situ infrared technology was used to investigate the effect of zinc species introduction on the fructose dehydration process, indicating suggesting that the introduction of zinc species enhances the transformation of fructose molecules.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xiaojun Dai,Yan Cheng,Qiang Wei,Meng Si,Yasong Zhou
In order to prepare non-noble metal supported hydroisomerization catalyst with high catalytic performance, this work first proposed a novel three-stage crystallization method to synthesize small-crystal and hierarchical SAPO-11 molecular sieve, and prepared the corresponding NiWS supported catalyst for the hydroisomerization of n-hexadecane. The physicochemical properties of the small-crystal and hierarchical SAPO-11 molecular sieve and the NiWS supported catalyst were analyzed via a series of characterization methods. It was found that the crystal size of SAPO-11-S was reduced to 21.8 nm and the particle size was reduced to 70–140 nm. SAPO-11-S was superior to SAPO-11-C in pore properties and acidity. The reason for the increase of the number of medium-strong B acid sites in SAPO-11-S was investigated by 29 Si MAS NMR characterization, and the formation mechanism of SAPO-11-S was proposed by tracking and analyzing the crystallization process of SAPO-11-S. The decrease of crystal size of SAPO-11 molecular sieve effectively improved the sulfidation degree of active metals and the dispersion degree of the active phase of the catalyst, and promoted more active phases to form “type II active phase”. Compared with NiW/SAPO-11-C, NiW/SAPO-11-S showed higher catalytic activity and isomerization selectivity, and the maximum i-hexadecane yield of NiW/SAPO-11-S was 44.77% higher than that of NiW/SAPO-11-C.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 2
·e202304152
·
IF 1.9
Xiaojun Dai,Yan Cheng,Tingting Liu,Lingjuan Mao
Graphical The effects of synthesis medium and synthesis conditions on the physicochemical properties of SAPO-11 molecular sieve were explored by combining the hydrothermal crystallization method with the fractional crystallization method. SAPO-11 molecular sieve has been widely used as the support of bifunctional catalyst for hydroisomerization of n-alkanes because of its mild acidity and unique one-dimensional pore structure, and has been widely used in industry. However, how to further improve and improve the physicochemical properties of SAPO-11 molecular sieve is still worth studying. In this work, fractional crystallization method was used to synthesize graded SAPO-11 molecular sieve. The effects of medium system, feed SiO 2 /Al 2 O 3 , crystallization time and crystallization temperature of the second crystallization process on the physicochemical properties of SAPO-11 molecular sieve were investigated from the perspectives of crystallinity, textural properties and acidity. The suitable synthesis medium and the best synthesis conditions were determined. It is expected to provide reference for the fractional crystallization synthesis of high performance SAPO-11 molecular sieve.
研究领域:
材料科学
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化学工程
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催化
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2017
·Vol. 7
·期 23
·5775-5784
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IF 5.773
Shuo Tao,Xiaolei Li,Guang Lv,Congxin Wang,Renshun Xu,Huaijun Ma,Zhijian Tian
The pore architecture and acidity of zeolite materials play crucial roles in the activity and selectivity of catalytic reactions. Herein, hierarchical SAPO-11 molecular sieve microspheres with uniform intercrystalline mesoporosity (ca. 4.3 nm) and tunable acidity were synthesized via dry-gel conversion (DGC) of a silicoaluminophosphate–organosilane composite. The products were comprehensively characterized using multiple techniques, including XRD, SEM, TEM, N2 adsorption–desorption, NH3-TPD, pyridine-adsorbed IR (Py-IR), TG and 29Si MAS NMR measurements. It is revealed that the products' acidity can be precisely tuned in a wide range by simply adjusting the water content used in the synthesis. The growth of such hierarchical SAPO-11 underwent a rearrangement of the mesopores: the original mesopores (ca. 17 nm) of the precursor were collapsed at the initial stage of crystallization and the final mesopores of the products were directed by the organosilane. More importantly, the Pt/hierarchical SAPO-11 catalysts exhibited enhanced isomerization selectivity in the hydroisomerization of n-dodecane, attributed to their excellent diffusion properties resulting from the hierarchical pore network. This work demonstrates a facile approach to synthesize hierarchical zeolites with tunable acidity, which is beneficial for catalytic reactions involving bulky molecules.
研究领域:
催化材料
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化学工程
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纳米材料
✓ 已验证
产品关联
DOI
高影响因子
Petroleum Science
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2022
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IF 4.757
Xue-Man Wang,Cheng-Long Wen,Yu Fan
Hierarchical SAPO-11 molecular sieve (ACS-11) was successfully synthesized employing the Al 2 O 3 /carbon (Al 2 O 3 /C) composite obtained through the pyrolysis of Al-based metal-organic framework (Al-MOF-96) as mesoporogen. Unlike other carbon-based mesoporogens with strong hydrophobicity, the Al 2 O 3 /C interacts with phosphoric acid and generates the AlPO 4 /C structure, which promotes the Al 2 O 3 /C dispersion in the synthesis gel of SAPO-11 and avoids the phase separation between them. The Al 2 O 3 /C as mesoporogen decreases the crystallite size of SAPO-11 via preventing the aggregation of SAPO-11 crystals. Additionally, the addition of Al 2 O 3 /C improves the Si distribution in the ACS-11 framework. Consequently, ACS-11 has smaller crystallites, more mesopores, and a greater amount of medium Brønsted acid centers than the conventional microporous SAPO-11 and the SAPO-11 synthesized using activated carbon as mesoporogen. The corresponding Pt/ACS-11 catalyst exhibits the maximal selectivity to multi-branched C 10 isomers (23.28%) and the minimal cracking selectivity (15.83%) in n-decane hydroisomerization among these catalysts. This research provides a new approach for preparing hierarchical silicoaluminophosphate molecular sieve-based catalysts to produce high-quality fuels.
研究领域:
催化材料
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化学工程
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燃料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 10
·1383
·
IF 3.9
Zhen Jiang,Liduo Chen,Yanhong Cui,Huijie Gao,Yisi Zhou,Wei Zhang,Yanhua Suo,Yingjun Wang
n-Alkane hydroisomerization over bifunctional catalysts is an effective approach for clean fuel production. However, achieving metal–acid synergy and enhancing the catalytic performance by the preparation of bifunctional catalysts with suitable proximity between the metal sites and Brønsted acid sites are still challenging. In this work, a series of Pt/SAPO-11 catalysts with different Pt loading applied inn-heptane hydroisomerization was synthesized. SAPO-11 was synthesized by the Instant Exactness Synthesis (IES) method, which, with unique morphology and pore structure, was chosen as support for the hydroisomerization catalysts; Pt/SAPO-11 was synthesized with the impregnation method, Pt nanoclusters with trace loading were fabricated over the SAPO-11 support, and the as-synthesized catalysts with different Pt loading were labeled as xPt/SAPO-11 (x = 0.1, 0.3, 0.5, 0.8 and 1.0). Various characterizations, including XRD, nitrogen adsorption–desorption, SEM, TEM, NH3-TPD and XPS, were carried out on catalysts to obtain deep insights into the microstructure and valence states of xPt/SAPO-11. The catalytic performance of xPt/SAPO-11, including catalytic selectivity and conversion, was investigated in then-heptane hydroisomerization in detail. Pt loading affected the catalytic properties of xPt/SAPO-11 in the hydroisomerization ofn-heptane. The selectivity of 0.5Pt/SAPO-11 toward isomers was about 65% with a conversion of 77% at 310 °C, which was obviously higher than other xPt/SAPO-11 catalysts.
研究领域:
催化化学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 12
·期 3
·894-905
·
IF 6.119
Jihui Yao,Yuzi Rong,Zeyan Gao,Xiaohua Tang,Fei Zha,Haifeng Tian,Yue Chang,Xiaojun Guo
To introduce a hierarchical porous structure into SAPO-34 zeolites and adjust their acid properties and crystalline size, a series of Zr-modified SAPO-34 zeolites (Zrx-SAPO-34 (x = 0.25, 0.50 and 0.75)) with hierarchical porous structure were synthesized by hydrothermal crystallization using palygorskite as a silicon and partial aluminum source, morpholine and tetraethylammonium hydroxide as organic structure directing agents and UiO-66 as a co-template agent. The obtained catalysts were characterized via XRD, SEM, TEM, EDX, N2-adsorption–desorption, NH3-TPD, FTIR, Py-IR, XRF, 29Si MAS NMR and TG analyses. The catalytic performance of Zrx-SAPO-34 in the methanol-to-olefin (MTO) transformation was investigated in a fixed bed reactor. The introduction of a hierarchical porous structure effectively enhanced the diffusion and mass transfer of the reactants/products, prolonging the catalytic lifetime. Additionally, the optimization of the acidity dramatically improved the selectivity for light olefins. Under the reaction conditions wherein the reaction temperature was 400 °C, the feed of WHSV was 2.0 h−1, the mass of the catalyst was 0.5 g and at atmospheric pressure, the Zr0.50-SAPO-34 zeolites exhibited optimum catalytic performance, where the methanol conversion was 100%, the light olefin selectivity was 98.66% and the catalytic lifetime was more than 1500 min.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2025
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IF 17.7
Ye Wang,Pan Gao,Dan Zhao,Tongrui Liu,Sitong Zhou,Miao Yang,Shiping Liu,Bing Li,Yida Zhou,Wenhao Cui,Guangjin Hou,Peng Tian,Zhongmin Liu
Silicoaluminophosphate (SAPO) molecular sieves possess diverse architectures and exceptional high-temperature hydrothermal stability, rendering them important acid catalysts. However, enhancing acid concentration of certain SAPO materials remains challenging, which limits their catalytic applications. Here, we report the synthesis of a series of SAPO materials using a developed SAPO precursor plus dual template (SPDT) strategy. A variety of SAPO materials characterized by high silica content and enhanced acidity, such as SAPO-34/56 intergrowths, SAPO-56, and SAPO-17, have been synthesized and thoroughly characterized using various techniques including integrated differential phase-contrast scanning transmission electron microscopy, two-dimensional solid-state nuclear magnetic resonance spectroscopy, and continuous rotation electron diffraction. The use of silica-enriched SAPO precursor combined with the flexible selection of the second template enables the crystalline phase regulation and improves the Si atoms incorporation into the framework. Notably, the synthesized SAPO-17 with abundant Si(4Al) species and unprecedentedly high acid density exhibits exceptional DeNO x activity after Cu loading, with NO x conversion exceeding 90% at 175–700 °C. This outstanding performance can be attributed to the unique ERI structure and the increased acidity of SAPO-17. This work not only presents an effective method for synthesizing SAPO molecular sieves with enhanced acidity but also offers a new perspective for expanding the active temperature range of the ammonia selective catalytic reduction reaction.
研究领域:
材料化学
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催化化学
·
无机非金属材料
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环境催化
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分子筛科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 97
·期 8
·2055-2067
·
IF 3.709
Xiaolong Liu,Jingye Ma,Minxin Wang,Hong Yuan
BACKGROUND A series of mesoporous Pt@KIT−6/SAPO−11 catalysts with SiO 2 :Al 2 O 3 molar ratios of 0.3, 0.4, or 0.5 and Pt loadings of 0.4, 0.8, or 1.2 wt% were prepared via an in situ encapsulation process using a PEO − PPO − PEO triblock copolymer (EO 20 PO 70 EO 20 , P123) as the mes. China 750001 oporous template and KIT−6 molecular sieves as the silicon source. RESULTS These catalysts were characterized by transmission electron microscopy (TEM), specific surface area analysis, and pyridine–infrared spectroscopy (Py − IR). The results showed that Pt nanoparticles with particle sizes of 3–7 nm were uniformly dispersed on the supports. These materials also exhibited good mesoporous structures with specific surface areas of 138–197 m 2 /g and average pore sizes of 7.1–9.9 nm. The specimens having a SiO 2 :Al 2 O 3 molar ratio of 0.4 also showed an orderly strip−shaped pore structure. The Py − IR results indicated that the catalysts had both Brønsted acid and Lewis acid sites, with total acid contents in the range of 77.8–131.1 μmol/g. CONCLUSION The decarboxylation of oleic acid using these materials under CO 2 was examined. The catalyst with a SiO 2 :Al 2 O 3 molar ratio of 0.4 and a Pt loading of 0.8 exhibited the best catalytic performance and a C8 − C17 alkanes yield as high as 85.1% at 340 °C by using a catalyst−to−oil mass ratio of 1:10 and a reaction time of 5 h. This performance was attributed to the ordered mesoporous structure of this catalyst along with its high surface area (173 m 2 /g), good crystallinity (92.8%), suitable acid content (98.6 μmol/g), and abundant Pt metal active sites. © 2022 Society of Chemical Industry (SCI).
研究领域:
催化化学
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材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2019
·
IF 4.191
Xiaoyun Li,Rui Xu,Qingling Liu,Min Liang,Jiaxin Yang,Shuangchun Lu,Guangbi Li,Lefu Lu,Chuanling Si
A one-step process was proposed for valorization of corn stover into furfural and levulinic acid catalyzed by SAPO-18 zeolites. With the aim to produce furfural and levulinic acid, the Brønsted to Lewis acid site ratios of SAPO-18 were modified. The influence of reaction temperature, time and the ratios of Brønsted to Lewis acid site on the valorization of corn stover were investigated. At the fixed catalyst concentration of 20 g/L, a furfural yield of 95.1% was observed at 205 °C for 40 min using SAPO-18 with Brønsted to Lewis acid site ratio of 0.11, and a levulinic acid yield of 70.2% achieved at 190 °C for 80 min using SAPO-18 with Brønsted to Lewis acid site ratio of 0.17. The Brønsted to Lewis acid site ratios of SAPO-18 were adjusted by altering the framework Si/Al ratio of SAPO-18. The SAPO-18 with lower Brønsted to Lewis acid site ratios showed higher activity for furfural production from corn stover and that with higher ratios exhibit superior catalytic effect for levulinic acid formation. The kinetic models considering the effect of Brønsted to Lewis acid site ratios agreed with the experiment values well, which provided detailed insights on the conversion of hemicellulose and cellulose fraction of corn stover into furfural and levulinic acid.
研究领域:
化学工程
·
生物质能
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Lei Chen,Wenjie Yao,Xu Chen,Gang Yang
The Cu-Ce modified SAPO-34/ZSM-5 (S-Z) composite molecular sieve catalysts were synthesized via a stepwise crystallization process using triethylamine (TEA) and tetraethylammonium hydroxide (TEAOH) as dual templates. This method significantly reduces the crystallization time from 24 hours to 12 hours. The incorporation of metal ions alters the structure and acid strength of the molecular sieves, thereby decreasing the rate of coke formation during the reaction, which in turn extends the catalyst's lifetime. Experimental results demonstrated that the catalyst's lifetime increased progressively with the addition of Ce. In the methanol-to-olefin reaction, the catalytic lifetime of the S-Z/Cu 0.05 -Ce 0.05 samples reached 1440 mins, approximately 480 mins longer than that of the S-Z samples, while maintaining a selectivity for low-carbon olefins at around 89.6%.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Chenglong Wen,Shanlei Han,Jundong Xu,Yu Fan
The article proposes a novel and eco-friendly method for synthesizing SAPO-11 in ethylene glycol (EG) and supercritical carbon dioxide (ScCO 2 ). The method incorporates ScCO 2 into EG to decrease the solubility of SAPO-11 precursors in EG and thereby forms a highly supersaturated solution of SAPO-11 precursors. The as-synthesized SAPO-11 possesses smaller particles, a larger external surface area, and a larger number of acid sites than the SAPO-11 synthesized in EG and the SAPO-11 synthesized in water and ScCO 2 , respectively. These advantages of the as-synthesized SAPO-11 endow the corresponding catalyst with superior dibranched isomer selectivity and low cracking selectivity during 1-octene hydro isomerization.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）