Petroleum Science
·
2022
·
IF 4.757
Wei-Long Zhan,Yu-Chao Lyu,Xin-Mei Liu,Lei Fan,Fu-Rang Li,Ye Yang
The Ni/SAPO-11 catalyst used for n-hexane hydroisomerization was prepared via a novel two-step crystallization strategy. It involves introduction of nickel salt into the pre-crystalized system of SAPO-11 by grinding followed by a second crystallization step. No extra solvent is introduced during the whole synthesis procedure which reduces waste liquid emissions significantly. More importantly, interaction between nickel and support is effectively regulated by the novel method to achieve a well dispersed nickel species and inhibit formation of inert nickel spinel simultaneously. Chemical environments of framework Si are tuned to enhance surface acidity of the Ni/SAPO-11 catalyst. It also shows smaller particle size which favors fast diffusion of reactants and products. Insights into the two-step crystallization indicate that accumulation of SAPO-11 precursors in the pre-crystallization stage, pH regulation by nickel salt and structural directing effect of Ni 2+ during the second crystallization period account for the rapid crystal growth and smaller particle size of the Ni/SAPO-11 catalyst. All the unique features endow the Ni/SAPO-11 catalyst higher activity and isomers selectivity than the Pt/SAPO-11 catalyst in n-hexane hydroisomerization.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 53
·47864-47872
·
IF 3.289
Chan Wang,Miao Yang,Wenna Zhang,Xiong Su,Shutao Xu,Peng Tian,Zhongmin Liu
With the aid of self-designed organophosphorous surfactant [2-(diethoxylphosphono)propyl]hexadecyldimethylammonium bromide (DPHAB), SAPO-34s with various special morphologies have been hydrothermally synthesized by using tetraethylammonium hydroxide (TEAOH), diethylamine (DEA) and triethylamine (TEA) as templates, respectively. The synthesized SAPO-34s were well characterized by XRD, XRF, SEM, N2 adsorption–desorption, solid state NMR and NH3-TPD measurements. The status of DPHAB was also investigated by using FT-IR, 13C NMR, TG–DTA and 31P NMR measurements as well as density functional theory calculations. It is found that the addition of DPHAB changes the crystal morphology dramatically and the aggregation degree of the crystals increases with the rising DPHAB/H3PO4 ratio. Moreover, microporous templates play an important role in the synthesis of mesoporous SAPO-34. TEAOH, which has the strongest interaction energy with the CHA framework among the investigated templates, shows the best cooperating ability with an organophosphorous surfactant to direct the formation of nanosized and mesoporous SAPO-34. The prepared SAPO-34s showed improved catalytic properties in the methanol-to-olefins (MTO) reaction.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 21
·6193-6203
·
IF 7
Daizong Han,Dongyuan Yang,Chenyao Bi,Guoqing Zhang,Fei Yang,Qingqing Hao,Jianbo Zhang,Huiyong Chen,Xiaoxun Ma
SAPO-14 (AFN topology) zeolite has been considered as an ideal catalyst for the methanol-to-propylene (MTP) reaction with a very high one-pass propylene selectivity, due to its unique framework structure containing narrow 8-MR pore openings and ultra-small AFN cages. However, the conventional synthesis of SAPO-14 by hydrothermal treatments generally suffers from issues relating to low-efficiency, difficulty in product collection, and being unfriendly to the environment. Herein, we showcase a facile strategy for the fast and efficient synthesis of highly crystalline SAPO-14 via dry-gel conversion (DGC) for the first time. The crystallization time can be shortened from 2 days to 8 hours at a lower temperature, and the product yield after 8-hour synthesis can be increased from 41.8 to 71.6% compared with the conventional hydrothermal synthesis. Influencing factors in the synthesis, including the molar ratio of dry gel, the time of crystallization, and the ratio of water-to-dry gel (WTDG), on the crystallinity, morphology, and textural properties of the product zeolites are systematically discussed, and the possible crystallization mechanism is also proposed. Successful attempts using four types of silica sources, including silicic acid, fumed silica, Ludox HS-40, and TEOS, confirm the flexibility and adaptability of the proposed synthesis strategy. The superior catalytic performance with not only a high propylene selectivity (76.2%) but also a large P/E ratio (7.19) demonstrates that the SAPO-14 produced by the DGC method is a high-performance catalyst candidate for the selective conversion of methanol to propylene.
研究领域:
化学工程
·
材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2024
·
IF 2.5
Liang Ni,Wang Haiyan,Wang Yujia,Kang Lei,Bai Yingzhi,Sun Na
A strategy was devised for the synthesis of SAPO-34, which involved a concentrated gel system-assisted two-step crystallization method. This strategy effectively controlled the size and morphology of SAPO-34. The successful synthesis of SAPO-34 crystals with micron-scale cubic morphology and nano-scale sheets were achieved using triethylamine as a low-cost template. The paper thoroughly examined the growth evolution that occurs during the crystallization process, and it delved into the factors such as gel concentration and crystallization conditions in the synthesis. Furthermore, potential theories regarding nucleation and growth mechanisms were suggested. A systematic study was conducted to examine how the morphology and acidity of SAPO-34 zeolites impact their catalytic performance. The results confirmed that the SAPO-34 with low silicon content and lamellar structure was successfully synthesized through a two-step crystallization within a gel system of H 2 O/Al 2 O 3 = 30, with a thickness of approximately 50–300 nm. SAPO-34 nanosheets demonstrated a substantial enhancement in catalytic performance, with a catalytic life of 370 min and an 84.1% selectivity towards light olefins.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2013
·
IF 3.172
Yan Liu,Wei Qu,Weiwei Chang,Shuxiang Pan,Zhijian Tian,Xiangju Meng,Marcello Rigutto,Alexander van der Made,Lan Zhao,Xiaoming Zheng,Feng-Shou Xiao
Hierarchically porous SAPO-11 zeolite (H-SAPO-11) is rationally synthesized from a starting silicoaluminophosphate gel in the presence of polyhexamethylene biguanidine as a mesoscale template. The sample is well characterized by XRD, N 2 sorption, SEM, TEM, NMR, XPS, NH 3 -TPD, and TG techniques. The results show that the sample obtained has good crystallinity, hierarchical porosity (mesopores at ca. 10 nm and macropores at ca. 50–200 nm), high BET surface area (226 m 2 /g), large pore volume (0.25 cm 3 /g), and abundant medium and strong acidic sites (0.36 mmol/g). After loading Pt (0.5 wt.%) on H-SAPO-11 by using wet impregnation method, catalytic hydroisomerization tests of n -dodecane show that the hierarchical Pt/SAPO-11 zeolite exhibits high conversion of n -dodecane and enhanced selectivity for branched products as well as reduced selectivity for cracking products, compared with conventional Pt/SAPO-11 zeolite. This phenomenon is reasonably attributed to the presence of hierarchical porosity, which is favorable for access of reactants on catalytically active sites. The improvement in catalytic performance in long-chain paraffin hydroisomerization over Pt/SAPO-11-based catalyst is of great importance for its industrial applications in the future.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Yuxiang Liu,Wanrong Liu,Yuchao Lyu,Xinmei Liu,Jun Zhang,Yu Gu,Jiankun Huang,Svetlana Mintova,Zifeng Yan
A hierarchical SAPO-11 was prepared by a grinding synthesis method (GSM) and added as a promoter to increase the iso-paraffin yield of gasoline in fluid catalytic cracking (FCC) reaction. Compared to the classical hydrothermal method , the GSM leads to the creation of intra-crystalline mesopores with the assistance of a surfactant (Cetyltrimethyl Ammonium Bromide, CTAB). CTAB acts as a structure directing agent and as a hard template during the crystallization of SAPO-11. CTAB micelles formed the intra-crystalline mesopores in SAPO-11 crystals. The intra-crystalline mesoporosity of the SAPO-11 is preserved at 800 °C under steaming, which renders the material as an appropriate component of the FCC catalyst. Besides, the presence of mesopores provides isomerization active sites and accelerates the desorption of iso-paraffin. The mesoporous SAPO-11 showed a higher selectivity for iso-paraffin and the yield of iso-paraffin increased by 2%.
研究领域:
化学工程
·
石油加工
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Runyu Ma,Yida Zhou,Huifang Wu,Jincong Wang,Xin Yan,Wei Huang,Tianlong Wang,Shutao Xu,Limin Ren
SAPO-37 molecular sieve, characterized by its three-dimensional 12-membered-ring FAU structure, has drawn wide attention due to its unique properties and catalytic potential. However, its susceptibility to framework collapse under low-temperature and humid conditions hinders practical applications, affecting both the reaction performance and sample storage. To tackle this, we utilized aluminum phosphate as a precursor for synthesizing SAPO-37, aiming to modify Si incorporation mechanisms and improve P and Al environments. Solid NMR spectroscopy combined with other techniques proves that the resulting SAPO-37-AP has enriched silicon islands, leading to reduced water adsorption, more reversible structural change, and significantly enhanced stability after low-temperature vapor treatment compared to conventional SAPO-37. Remarkably, SAPO-37-AP, after water vapor treatment, still exhibits superior performance in the liquid-phase Beckmann rearrangement reaction. This approach enhances stability, reduces templating agent amounts, and improves the solid product yield, offering promising practical applications.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Gang Li,Shuanshi Fan,Zijian Zhang,Yanhong Wang,Xuemei Lang,Jing Li
SAPO-34 zeolite membranes were activated by ultraviolet (UV) radiation at low temperatures to reduce grain boundary defects. The successful detemplation of SAPO-34 zeolite powders using UV radiation was confirmed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and nitrogen adsorption-desorption. The irradiance exerted a significant impact on the quality of UV-detemplated SAPO-34 membranes. Under optimal UV detemplation conditions, SAPO-34 membranes showed a moderate H 2 permeance of ∼10 −7 mol Pa −1 m −2 s −1 , with a H 2 /i-C 4 H 10 permselectivity over 75 under room temperature. The membranes showed an exceptionally low CO 2 permeance in comparison with N 2 and CH 4 despite the smaller molecular size of CO 2 , resulting in an unprecedentedly high H 2 /CO 2 permselectivity over 50, which was ascribed mainly to the intense interaction between the CO 2 molecules and confined organic structure directing agent (OSDA) residue in membrane channels. The temperature dependence of singe-gas permeance through SAPO-34 zeolite membranes showed that gases, including He, H 2 , CO 2 , CH 4 , C 2 H 6 , C 3 H 8 , and i-C 4 H 10 , markedly increased as the temperature increased, indicating an activated diffusion mechanism. The activation energies for H 2 permeation through the SAPO-34 membranes were 17–23 kJ mol −1 , which were reasonable based on the correlation between the activation energy for H 2 permeation and the average pore size for reported membranes by assuming minimal grain boundary defects in the UV-detemplated SAPO-34 membranes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2024
·Vol. 11
·期 3
·036505
·
IF 1.8
Zhen Jiang,Liduo Chen,Yanhong Cui,Yanhua Suo,Wei Zhang,Yisi Zhou,Yingjun Wang
The monometallic Pt/SAPO-11 and bimetallic Ni-Pt/SAPO-11 catalysts were synthesized with Instant Exactness Synthesis (IES) method and characterized by XRD, nitrogen adsorption–desorption, SEM, TEM, FT-IR, Py-IR, NH3-TPD and XPS, and their properties were evaluated for the n-heptane hydroisomerization. The catalysts had spherical structure and moderate acid strength, and exhibited good n-heptane conversion and catalytic selectivity toward n-heptane isomers. Typically, Ni-Pt/SAPO-11 exhibited an isomer selectivity of 80.9% with a conversion of 69.9% at 310 °C, which was obviously better than Pt/SAPO-11 (isomer selectivity of 75.1% with a conversion of 60.6% at 310 °C). Moreover, the Ni-Pt/SAPO-11 catalyst displayed higher percentage of i-heptane (79%) and lower percentage of n-heptane (6%) than Pt/SAPO-11. The continuous test of 360 min indicated Ni-Pt/SAPO-11 catalyst had good catalytic stability. Bimetallic Ni-Pt alloy loaded on SAPO-11 had significantly effect on catalytic properties of n-heptane hydroisomerization.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Yongxin Ding,Jun Lin,Panjie Yu,Hongwei Zhang,Yongde Ma,Zhenping Cai,Yanning Cao,Kuan Huang,Lilong Jiang
The design of novel practical catalysts is critical for the blossoming of biodiesel green-energy, in which Mo-based catalysts are of particular interest. In this work, an in-situ synthesis method was proposed to obtain a combo Mo-based ionic liquid and SAPO-11 catalyst. The catalyst presents both highly dispersed MoS 2 as hydrodeoxygenation active sites and acidic sites for isomerization. MoS 2 with a few fine layers can be identified based on TEM images and the Brønsted acid sites are dominant based on Pyridine-IR analysis. A great performance of MoS 2 /C 8 min-15 %SA can be obtained under optimized reaction conditions with 100 % conversion of methyl palmitate, 75.0 mol% hydrodeoxygenation to n -C 15 -C 16 , and 20.5 mol % isomerization to i -C 15 -C 16 . The structure and activity of the catalyst can be retained at least for 4 cycles. Thin layers and high sulfurization, large amount of Brønsted acid sites, and suitable reaction conditions are key points to achieve a significant performance and avoid over cracking and deactivation. On basis of detected intermediates and kinetic data simulations, a complex reaction pathway was proposed and the specific k values for each elementary reaction were provided for the hydrodeoxygenation and isomerization of methyl palmitate.
研究领域:
催化化学
·
绿色能源
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2014
·Vol. 90
·期 3
·415-422
·
IF 2.494
Yanping Chen,Yiming Xu,Dang-guo Cheng,Yingcai Chen,Fengqiu Chen,Xiaoyong Lu,Yiping Huang,Songbo Ni
BACKGROUND The synthesis of C 2 –C 4 hydrocarbons from coal or biomass-derived syngas has received increasing attention because of the resource constraints of petroleum. The present study explores direct production of hydrocarbons from syngas over bifunctional catalyst containing methanol synthesis catalyst CuO–ZnO–Al 2 O 3 (CZA) and SAPO-34 zeolite. RESULTS The synthesis of C 2 –C 4 hydrocarbons from syngas was investigated over CZA/SAPO-34 bifunctional catalyst at temperatures ranging from 240 to 440°C. The results indicate that higher temperatures aggregate Cu metal and lead to the deactivation of CZA. The predominant products are dimethyl ether (DME) and methanol at temperatures from 280 to 360°C and a small amount of hydrocarbons are found due to the deactivation of SAPO-34 caused by a type of coke named ‘inert coke’. While 96.5% selectivity of C 2 –C 4 hydrocarbons in products of all hydrocarbons can be obtained at 400°C with less coke named ‘active coke’. CONCLUSION Reaction temperatures have significant effect on the selectivity of C 2 –C 4 hydrocarbons and coke species of SAPO-34. The ‘active coke’ of poly methyl-substituted benzene/naphthalene (MB/MN) acts both as an intermediate and as coke deposition. The ‘inert coke’ of poly methyl-substituted adamantine (MA) and other groups-substituted benzene/naphthalene acts only as coke depositions. Comprehensive consideration of the characteristics of this bifunctional catalyst, shows that a moderate temperature for C 2 –C 4 hydrocarbons synthesis from syngas might be approximately 400°C. © 2014 Society of Chemical Industry
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Zhaopeng Liu,Youming Ni,Zhongpan Hu,Yi Fu,Xudong Fang,Qike Jiang,Zhiyang Chen,Wenliang Zhu,Zhongmin Liu
The utilization of metal oxide-zeolite catalysts in the syngas-to-olefin reaction is a promising strategy for producing C 2 –C 4 olefins from non-petroleum resources. However, the effect of the crystal phase of metal oxides on the catalytic activity of these oxides is still ambiguous. Herein, typical metal oxides (ZnO/ZrO 2 ) with different crystal phases (monoclinic ( m -ZrO 2 ) and tetragonal ( t -ZrO 2 )) were employed for syngas conversion. The (ZnO/ m -ZrO 2 +SAPO-34) composite catalyst exhibited 80.5% selectivity for C 2 –C 4 olefins at a CO conversion of 27.9%, where the results are superior to those (CO conversion of 16.4% and C 2 –C 4 olefin selectivity of 76.1%) obtained over (ZnO/ t -ZrO 2 +SAPO-34). The distinct differences are ascribed to the larger number of hydroxyl groups, Lewis acid sites, and oxygen defects in ZnO/ m -ZrO 2 compared to ZnO/ t -ZrO 2 . These features result in the formation of more formate and methoxy intermediate species on the ZnO/ m -ZrO 2 oxides during syngas conversion, followed by the formation of more light olefins over SAPO-34. The present findings provide useful information for the design of highly efficient ZrO 2 -based catalysts for syngas conversion.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）