Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 10
·5608-5616
·
IF 7.443
Chan Wang,Miao Yang,Peng Tian,Shutao Xu,Yue Yang,Dehua Wang,Yangyang Yuan,Zhongmin Liu
A spherical self-assembly of SAPO-34 nanosheets was hydrothermally synthesized by using a quaternary ammonium-type organosilane surfactant [3-(trimethoxysilyl)propyl]octadecyldimethylammonium chloride (TPOAC) as the mesoporogen and a part of the silica source, and diethylamine (DEA) as the microporous template. The prepared materials were well characterized by XRD, XRF, SEM, TEM, N2 adsorption–desorption, NH3-TPD, NH3-adsorbed IR and pyridine-adsorbed IR measurements. It revealed that the morphologies, compositions and acidity of the SAPO-34 products changed significantly with the increased TPOAC/TEOS ratio, showing that the TPOAC/TEOS ratio had a significant impact on the crystallization process of SAPO-34. Solid state 13C, 29Si NMR and TG-DTA analyses were further conducted to investigate the status of TPOAC in the final products. A possible crystallization process involving TPOAC was proposed. The catalytic performances of the synthesized SAPO-34s were evaluated using the MTO reaction. The optimal SAPO-34 nanosheet assemblies with a hierarchical porous structure displayed a remarkably enhanced catalytic lifetime and high yields of light olefins.
研究领域:
材料科学
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化学工程
·
催化
·
无机化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Siyuan Zhao,Ke Ma,Kailong He,Xiaoxun Ma,Chengyi Dai
Due to cost and energy consumption constraints, converting benzene into ethylbenzene using low-cost syngas instead of ethylene as an alkylation reagent is significant. However, when using syngas as the reaction raw material, generating ethylated side chains on the benzene ring is challenging. Instead, toluene/xylene becomes the primary product. We used a three-bed series connection method in a reactor, achieving one-step high selectivity of syngas and benzene to produce ethylbenzene. In the first bed layer (ZnAl2O4/SAPO-34), the syngas was first converted into methanol/dimethyl ether (DME) on ZnAl2O4. Then, it was further converted into low-carbon olefins on SAPO-34, with the microporous shape-selective effect of SAPO-34, inhibiting the generation of toluene/xylene in the alkylation of benzene with methanol/DME. At the same time, we proved that the absence of microporous shape-selective effect acid sites on the outer surface of S34 can lead to the occurrence of side reactions of benzene and methanol/DME methylation. In the second bed layer, SAPO-34 could continue to convert unconverted methanol/DME in the first bed layer into low-carbon olefins. In the third layer (ZSM-5), ethylene and benzene underwent highly selective alkylation on ZSM-5 to convert it into ethylbenzene. We found a “volcanic” curve relationship between the selectivity of ethylbenzene and the Brønsted acid site density of ZSM-5. On the one hand, Brønsted acid could catalyze the formation of ethylbenzene from benzene and ethylene; On the other hand, excessive Brønsted acid could lead to the isomerization of ethylbenzene to toluene/xylene. When the Brønsted acid showed a site density of 0.7 mmol/g, the selectivity of ethylbenzene was as high as 87%, with a byproduct of xylene showing only 0.3%, which is usually difficult to separate from ethylbenzene. Finally, the three-bed catalytic system showed no deactivation after 100 h.
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
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Peng Zhang,Fangfang Li,Xuefang Yao,Pengze Zhang,Yukai Wu,Mengmeng Xi,Fanhui Meng,Lihua Kang,Mingyuan Zhu
The GaZrO x solid solution has been recently employed in OX-ZEO bifunctional catalysts for efficient conversion of syngas to light olefins, but it remains challenging to identify the specific contributions of Zr and Ga and to understand the detailed reaction mechanisms due to the structural complexity. To address this complexity and elucidate the active sites over the Zr-Ga oxide system, this study presents a catalyst designed by physical mixing ZrO 2 with different crystalline phases ( m -ZrO 2 & t -ZrO 2 ) and α -Ga 2 O 3 . The physical mixture of m -ZrO 2 and α -Ga 2 O 3 achieves a high CO conversion of 39.1 %, with light olefins selectivity of 87.3% among hydrocarbons after combined with SAPO-34, surpassing the performance of physical mixture of t -ZrO 2 and/or α -Ga 2 O 3 with SAPO-34. Combining the various characterizations and DFT calculations, we have confirmed that m -ZrO 2 site, enriched with oxygen vacancies and surface hydroxyl groups, is essential for CO adsorption and HCOO* intermediate formation, while the α -Ga 2 O 3 site plays a key role in the dissociation of H 2 . Furthermore, the electron transfer from m -ZrO 2 to α -Ga 2 O 3 in their mixture is more efficient than in a physically mixed t -ZrO 2 and α -Ga 2 O 3 . This accelerates the H 2 dissociation and boosts the spillover of hydrogen from α -Ga 2 O 3 to m -ZrO 2 , leading to the formation of more CH 3 O* intermediates and higher light olefins yield when combined with SAPO-34.
研究领域:
催化化学
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材料科学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2024
·Vol. 18
·期 10
·1-10
·
IF 4.3
Zhao Qiao,Wang Hongyu,Liang Haoting,Han Xiaoxue,Wei Chongyang,Wang Shiwei,Wang Yue,Huang Shouying,Ma Xinbin
Lower olefins, produced from syngas through Fischer-Tropsch synthesis, has been gaining worldwide attention as a non-petroleum route. However, the process demonstrates limited selectivity for target products. Herein, a hybrid catalyst system utilizing Fe-based catalyst and SAPO-34 was shown to enhance the selectivity toward lower olefins. A comprehensive study was conducted to examine the impact of various operating conditions on catalytic performance, such as space velocity, pressure, and temperature, as well as catalyst combinations, including loading pattern, and mass ratio of metal and zeolite. The findings indicated that the addition of SAPO-34 was beneficial for enhancing catalytic activity. Furthermore, compared with AlPO-34 zeolite, the strong-acid site on SAPO-34 was identified to crack the long-chain hydrocarbons, thus contributing to the lower olefin formation. Nevertheless, an excess of strong-acid sites was found to detrimentally impact the selectivity of lower olefins, attributed to the increased aromatization and polymerization of lower olefins. The detailed analysis of a hybrid catalyst in Fischer-Tropsch synthesis provides a practical strategy for improving lower olefins selectivity, and has broader implications for the application of hybrid catalyst in diverse catalytic systems.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2024
·
IF 4.4
Kewei Wang,Yuhao Bai,Jie Tao,Weijie Hu,Long-Sheng Wang,Meng Zhang,Li-Ming Wu
The crystal size and uniformity of zeolites are crucial for their excellent performance in various industrial applications. Here, by utilizing commercial micrometer-sized zeolites as seeds and adjusting the weight percentage of seeds from 0 % to 5 %, the crystal sizes of silicoaluminophosphate SAPO-34 samples first decrease from 12.47 μm (S0) to 3.04 μm (S4), then increase to 5.34 μm (S5). Correspondingly, their relative crystal size deviations first decrease from 183.32 % to 60.53 %, then increase to 115.17 %, and the crystal size uniformity factors first increase from 0.33 to 1, then decrease to 0.53. The crystal size uniformity factor of sample S4 equals 1, indicating that it exhibits the best crystal size uniformity. This method is also applicable to aluminosilicate zeolites. By adjusting the weight percentage of seeds from 0 % to 3 %, the crystal sizes of ZSM-5 samples first decrease from 13.61 μm (Z0) to 2.49 μm (Z2), then increase to 4.46 μm (Z3); correspondingly, their crystal size uniformity factors first increase from 0.42 to 1, then decrease to 0.71. In addition, this route significantly enhances the yields and relative crystallinities of both SAPO-34 and ZSM-5 zeolites. Specifically, the yield and relative crystallinity of SAPO-34 zeolite increase by 40.71 % and 8.45 % respectively, while the yield and relative crystallinity of ZSM-5 zeolite improve by 24.05 % and 12.55 % individually. Notably, in the methanol to olefins (MTO) reaction, the propylene selectivity to butene selectivity ratio is inversely related to the crystal size; this suggests that crystal size may play a primary role in the formation of propylene and butene, with smaller crystal sizes being more favorable for the formation of propylene compared to butene. Furthermore, sample S4, which has a crystal size uniformity factor of 1 and a crystal size of 3.04 μm, exhibits excellent MTO performance; its catalytic lifetime increases by 69 %, and selectivity for ethylene plus propylene increases by 6.3 % in comparison to conventional sample S0.
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 Environmental Chemical Engineering
·
2026
·Vol. 14
·期 1
·121143
·
IF 7.2
Rui Xiang,Tao Du,He Jia,Yingnan Li,Peng Chen,Qiang Yue,Heming Wang,Yisong Wang
Global warming caused by CO 2 has drawn increasing attention in recent years. Direct hydrogenation of carbon dioxide to light olefins (C 2 = -C 4 = ) is considered a promising strategy for carbon reduction. However, the catalytic performance of metal oxide/zeolite bifunctional catalysts still requires further optimization to enhance CO 2 conversion efficiency and C 2 = -C 4 = selectivity. This study incorporates a hierarchical porous structure into SAPO-34 molecular sieves to modulate their pore channel structure, while Mg doping is introduced into ZnZrOₓ to improve its crystal structure. Characterization results, including NH 3 -TPD and CO 2 -TPD, reveal that structural modifications improve the acidity of the SAPO-34 molecular sieve and enhance the CO 2 adsorption and activation capacity of ZnZrO x . The catalytic performance of the Z/S bifunctional catalyst was evaluated under the following reaction conditions: mass ratio of ZnZrO x to SAPO-34 (Z:S) = 1:1, reaction temperature = 380°C, reaction pressure = 2 MPa, and gas hourly space velocity (GHSV) = 16,000 mL·g cat ⁻¹ ·h⁻¹ . The bifunctional catalyst, composed of ZnZrO x doped with 3 % Mg and SAPO-34 with a mesoporous structure, demonstrated a CO 2 conversion of 10.7 % and a C 2 = -C 4 = selectivity of 78.8 % under these conditions, outperforming other Z/S catalysts. This work offers both theoretical and experimental insights for the design of highly efficient bifunctional catalysts for CO 2 hydrogenation to C 2 = -C 4 = .
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Dandan Tian,Yong Men,Shuang Liu,Jinguo Wang,Zhuping Li,Keye Qin,Tianle Shi,Wei An
Advances in design concept of oxide-zeolite (OX-ZEO) bifunctional tandem catalysts have demonstrated its potential for highly enhanced selectivity and yield in CO 2 conversion by assigning CO 2 activation and C-C coupling to specific oxide and zeolite , respectively. However, the crystalline structural effects of oxides have not been thoroughly investigated. Here, ZnO/ZrO 2 with different ZrO 2 crystalline phases modulated by Li doping has been used as an oxide catalyst to combine with SAPO-34 as a bifunctional composite catalyst for CO 2 hydrogenation to light olefins . With the transformation of the support ZrO 2 crystalline phase from tetragonal phase to mixed crystalline phase in the catalyst, the CO 2 conversion and yield of target product light olefins were significantly improved. The best-performing ZnO/5Li-ZrO 2 catalyst exhibited a CO 2 conversion of 28.56%, light olefins selectivity of 82.00% with a yield of 8.77% along with good stability under the reaction conditions of 380 °C, 3 MPa, and 6000 mL/g/h. The characterization results by XRD , Raman, HRTEM , XPS and CO 2 -TPD confirmed that the highly enhanced catalytic performance was attributed to the strong interaction between the mixed crystal phase 5Li-ZrO 2 and ZnO, which generated a large number of oxygen vacancies for CO 2 activation. The results indicate that controlling the crystal phase of the oxide support is of prime importance in designing more active and selective oxide-zeolite bifunctional catalysts for high-efficiency CO 2 to light olefins conversion.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2011
·Vol. 141
·期 12
·1821-1827
·
IF 1.907
Duan Chao,Zhang Xin,Zhou Rui,Hua Yuan,Chen Jie,Zhang Li
HZSM-5/SAPO-34 zeolite composites were prepared by hydrothermal synthesis (ZS-HS) and mechanical mixture (ZS-MM), respectively. ZS-HS showed higher propylene yield and better catalytic stability in ethanol conversion than ZS-MM as well as HZSM-5 and SAPO-34. In case of ZS-HS, SAPO-34 at least partially overlapped on HZSM-5, which resulted in the interfacial interaction of HZSM-5 and SAPO-34. Such interaction significantly modified the texture and the acidity of ZS-HS, which in turn affected its catalytic reactivity. ZS-HS showed the higher apparent formation rate of propylene, due to its moderate concentration and strength distribution of acid sites. Propylene, ethylene and butylenes might produce through the parallel reaction pathways and the common intermediate on ZS-HS. Graphical [Time course of ethanol conversion on ZS-HS and ZS-MM catalysts.]
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2014
·Vol. 14
·期 9
·6900-6906
·
IF 1.339
Chu Yue,Zhang Qiang,Wu Tongwei,Nawaz Zeeshan,Wang Yao,Wei Fei
Ultra-dispersed precious metal nanoparticles with good thermal stability are highly required for heterogeneous catalysis. However, the efficient and effective strategy to disperse ultra-fine precious metal nanoparticles at high reaction temperature is still not fully understood yet.
In this contribution, a family of catalysts with ultra-small Pt nanoparticles were prepared using impregnation method by adjusting the zeolite content in the SAPO-34 and γ-Al2O3 mixed support. The effect of Pt nanoparticle size on the catalytic activity,
selectivity, and stability was investigated in the propane dehydrogenation reaction. Catalyst with smaller Pt particles exhibits better catalytic performance. Both the highest Pt dispersion and the best catalytic activity can be achieved by using SAPO-34 and γ-Al2O3
mixed support with 70 wt.% of SAPO-34. The size and structure of the Pt nanoparticles on the optimal catalyst were characterized by transmission electron microscopy. Pt nanoparticles with an average size of 1.32 nm were observed. There were stronger metal-support interactions between the oxidized
tin species and Pt particles on SAPO-34 support compared to that on γ-Al2O3 catalyst. These lead to high Pt dispersion and consequently good catalytic performance.
研究领域:
催化化学
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材料科学
·
化学工程
·
纳米技术
·
多相催化
✓ 已验证
DOI
高影响因子
Nanoscale
·
2026
·
IF 5.2
Linlong Hu,Chentao Wang,Huibin Wang,Hua Pan,Mi Yan,Ke Wang,Pengfei Xie
CO2 reduction to light olefins is an important pathway toward carbon neutrality, but it is hindered by low thermodynamic conversion and the inherent trade-off between activity and selectivity. To address this challenge, a bifunctional catalyst consisting of Cu single atoms anchored on ZrO2 and SAPO-34 (Cu1/ZrO2-SAPO-34) was developed. This catalyst achieves 84.3% light olefin selectivity and 15.0% CO2 conversion, with stable performance maintained over 100 hours. In this catalyst, Cu single atoms, ZrO2, and SAPO-34 exhibit clear division of labor and synergy, responsible for CO2 activation, active site stabilization, and olefin selectivity control, respectively. Mechanistic investigations using in situ DRIFTS and DFT calculations demonstrate that the interaction between Cu single atoms and ZrO2 facilitates the further hydrogenation of formate intermediates to methoxy species, while reducing the energy barrier for methoxy hydrogenation to methanol, thus ensuring high light olefin selectivity in subsequent conversion over SAPO-34. This work provides new insights for CO2 conversion and the design and application of single-atom catalysts in tandem catalytic reactions.
✓ 已验证
DOI
PubMed
高影响因子
APPLIED ENERGY
·
2017
·
IF 7.182
Xiaowen Zhang,Xin Zhang,Helei Liu,Wensheng Li,Min Xiao,Hongxia Gao,Zhiwu Liang
In this work, the regeneration of rich CO 2 -loaded monoethanolamine (MEA) solvent with two catalysts (e.g. SAPO-34 and SO 4 2− /TiO 2 ) was investigated in order to reduce the energy requirement for solvent regeneration. The regeneration behavior with and without catalyst of a 5M MEA solution with an initial CO 2 loading of 0.5 mol CO 2 /mol amine at 96 °C was studied to compare their CO 2 desorption rate and heat duties. The results show that the two solid acid catalysts can reduce the heat duty for solvent regeneration and increase the CO 2 desorption rate in comparison with blank test. The mechanism of CO 2 desorption with catalyst in 5M MEA was proposed based on the result of catalyst characterization (e.g. N 2 absorption/desorption experiment, Py-IR, NH 3 -TPD, FT-IR and XRD) to better understand the desorption process. The results indicate that SAPO-34 with the higher joint value of Brϕnsted/Lewis acid sites ratio (B/L) and mesopore surface area (MSA) shows the faster CO 2 desorption rate and lower heat duty than SO 4 2− /TiO 2 . Based on the experimental results, the addition of solid acid catalysts into amine solution could be considered as one of choices to reduce the heat duty for CO 2 desorption from CO 2 -loaded amine solvent.
研究领域:
化学工程
·
环境科学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Xiaonan Zhao,Wei Liu,Xiufeng Liu,Baoquan Zhang
Mixed matrix membranes (MMMs) are challenged by the poor compatibility between fillers and a polymer matrix that leads to the weakened performance for gas separation. The surface modification of fillers with aminosilane should be an effective approach to improve their compatibility within the polymer matrix. 3-(2-Aminoethylamino)propyl-dimethoxymethylsilane (APDS) was used as a silane coupling agent for modification of sheet-like silicoaluminophosphate-34 (SAPO-34) crystal grains, and novel MMMs were fabricated by incorporating APDS-modified SAPO-34 crystal grains into a Pebax MH 1657 polymer. Based on characterization using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and mechanical tests, the incorporation of an APDS-modified SAPO-34 into Pebax matrix led to much enhanced interfacial adhesion within the MMM. In addition, the effect of the filler content in the MMM on the separation performance of a CO2/CH4 gas mixture and pure gases (CO2 and CH4) was investigated. Compared with available Pebax-based MMMs in the literature, the prepared MMM containing 8 wt % APDS-modified SAPO-34 exhibited the satisfactory CO2 permeability of ca. 137 Barrer and the highest selectivity of 34.7 for the CO2/CH4 gas mixture. It was believed that the excellent separation performance and good stability of the prepared MMM in this study should be due to the good interfacial compatibility of APDS–SAPO-34 fillers together with their strong affinity for CO2 within the MMM.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）