SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Li Peng,Zhaofeng Duan,Shumin Cen,Xuehong Gu
High-silica CHA (SSZ-13) zeolites membranes, with pore size between the molecular size of CO 2 and N 2 or CH 4 , are promising for some industrial CO 2 separation process. Considering water is typically present in these industrial gas feed and the negative impact of moisture on the membranes’ gas permeation, it is highly desirable to increase the surface hydrophobicity of membranes to reduce the adsorption of water. In this paper, a W-doping strategy was proposed to increase the hydrophobicity of SSZ-13 membranes by eliminating the silanols on the surface, and the W-doped high-silica CHA (W-SSZ-13) zeolite membranes were prepared for the first time. Characterizations such as SEM, XRD, and XPS confirmed the successful incorporation of W into CHA membrane. The incorporation of W reduced the pore mouth size, and the W-SSZ-13 zeolite membranes showed improved CO 2 /N 2 and CO 2 /CH 4 separation performance. After W-doping, the maximum separation factors ( α max ) for the CO 2 /N 2 mixture with equimolar composition under dry conditions increased from 8.8 to 16.9, and for the equimolar CO 2 /CH 4 mixture, the value increased from 105.9 to 176. The W-SSZ-13 membranes also showed better separation performance under wet conditions. For both systems, the W-SSZ-13 membrane showed higher α max and less CO 2 permeance reductions, indicating a more resistance in wet conditions.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 17
·10156-10162
·
IF 2.599
Cui Yucun,Tong Xueting,Li Ying,Chen Mingjiong,Zhou Wenyong,Ren Silin,Li Lei,Yan Zheng,Zhu Longfeng
We show that a nickel-amine complex (nickel-diethylenetriamine, Ni-DETA) is an efficient organic template for the one-pot synthesis of Ni-SSZ-13 zeolite. The effects of the reaction compositions, including the molar ratios of SiO 2 /Al 2 O 3 , H 2 O/Al 2 O 3 , Ni-DETA/Al 2 O 3 , and Na 2 O/Al 2 O 3 , on the synthesis of the pure product were investigated using different temperatures and synthesis times. Physicochemical characterizations, including XRD, SEM, and 27 Al NMR, show that the zeolitic product has good crystallinity, uniform crystals, and contains a tetrahedral Al 3+ species. The N 2 sorption isotherms, TG–DTA curves, IR spectra, and UV–Vis spectra show that Ni-DETA acts as a template in the product obtained. Interestingly, Ni-SSZ-13 zeolite is obtained by the conversion of Ni-Y zeolite produced in the crystallization process.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ADSORPTION SCIENCE & TECHNOLOGY
·
2013
·
IF 0.559
Jiaodi Tang,Yaping Zhou,Wei Su,Xiuwu Liu,Yan Sun
Zeolite SSZ-13 was synthesized by a traditional hydrothermal method, and characterized by powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The porous structure of the samples was determined from nitrogen uptake measurements at 77 K, and the surface properties were analyzed by Fourier transform infrared spectroscopy. The zeolite SSZ-13 had a type I isotherm with a uniform pore-size distribution and most pores were less than 1 nm. The Langmuir surface area was 703 m2/g. The adsorption of various gases on SSZ-13 was studied experimentally and a high selectivity for CO2 over N2 was achieved.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2021
·Vol. 134
·期 2
·837-849
·
IF 2.081
Zhao Xinhong,Niu Li,Hao Zongyi,Long Xuefeng,Wang Dongliang,Li Guixian
SSZ-13 has been widely used in catalysis and adsorption due to its excellent hydrothermal stability and large specific surface area. It was reported that the long crystallization time was one of the primary challenges limiting its industrial progress. In this paper, we reported a novel solid-state grinding route of synthesizing SSZ-13 zeolite, which was based on interzeolite transformation strategy and promoted by sodium persulfate (Na 2 S 2 O 8 ). The effects of the amount of Na 2 S 2 O 8 and crystallization time on the purity and crystallinity of SSZ-13 zeolite were studied by XRD measurements in detail. The results indicated that the crystallization time could be significantly shortened from 72 to 24 h when the molar ratio of Na 2 S 2 O 8 /SiO 2 was changed from 0 to 0.01, proving that Na 2 S 2 O 8 has the ability of accelerating the crystallization of SSZ-13 as a hydroxyl radical reagent. Three typical SSZ-13 materials and a reference sample were used as the catalysts for methanol-to-olefins reaction (MTO) and their physicochemical properties were analyzed by SEM, N 2 physisorption and NH 3 –TPD techniques. The SEM characterization results showed that the crystal size of SSZ-13 synthesized in the presence of Na 2 S 2 O 8 was larger than that of the one in the absence of it. The NH 3 –TPD results showed that the introduction of Na 2 S 2 O 8 could modulate the acid properties of SSZ-13 zeolites. The MTO tests revealed that the catalytic lifetime of one sample with Na 2 S 2 O 8 promoter (SSZ-13-0.01M-24h) was much longer than that of the other three samples. The observed difference in catalytic stability was mainly attributed to their various concentrations of medium strong acid sites.
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 COMMUNICATIONS
·
2024
·
IF 4.4
Na Wang,Qianrui Li,Jinping Yuan,Di Zhao,Hongjian Yang,Yige Wang
Ag + -exchanged SSZ-13 zeolites with single-phase white-emitting, especially obtained in a mild temperature (400 °C), are highly desirable for the construction of white LEDs, but rarely reported. Herein, luminescent silver nanoclusters composites were synthesized though treating H-SSZ-13 zeolites in the presence of a moderate amount of sodium hydroxide solutions, by assembling the silver nanoclusters in the modified SSZ-13 zeolites, followed by heating under mild conditions, which it bright white light emission phenomena under a 365 nm UV light. This white emitting may be ascribed to the collapse of the zeolite skeleton due to the etching of the zeolites by NaOH, thereby formation and stabilization of silver nanoclusters within modified Na-SSZ-13 zeolites. For the first time, the white-emitting Ag@Na-SSZ-13-400 zeolites phosphors were obtained at a mild temperature (400 °C) with a photoluminescence quantum yield (PLQY) of 24.45 % and the CIE chromaticity coordinate were (0.26, 0.33) under the 360 nm excitation. We believe that this work may provide a prospect for application of SSZ-13 zeolites and the preparation of luminescent AgNCs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Shichao Han,Xiaomin Tang,Ye Ma,Qinming Wu,Jiaqi Shi,Jian Li,Xiangju Meng,Anmin Zheng,Feng-Shou Xiao
The selective catalytic reduction of nitrogen oxide with methane (CH4–SCR) has been considered as an alternative technology for the simultaneous removal of NOx and CH4, and one of the efficient catalysts for this reaction is Co-exchanged SSZ-13 (Co-SSZ-13) zeolite catalyst. However, the preparation of the Co-SSZ-13 zeolite catalyst is costly due to the use of an expensive organic template and Co exchange. We demonstrate here the design of a low-cost cobalt–amine complex (Co–DETA) as a novel structure-directing agent (SDA) for the one-pot synthesis of Co-SSZ-13 zeolite with the assistance of theoretical calculations. Physicochemical characterizations including X-ray diffraction, scanning electron microscopy, N2 sorption, and magic-angle spinning nuclear magnetic resonance show that the Co-SSZ-13 zeolite has good crystallinity, a cubic morphology, a high surface area, and four-coordinated aluminum species. Furthermore, thermogravimetry–differential thermal analysis, Fourier transform infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy confirm that the Co–DETA complex acts as a SDA for the synthesis of Co-SSZ-13 zeolite. More importantly, the Co-SSZ-13 zeolite exhibits good catalytic performance in the CH4–SCR reaction with 10% H2O in the feed gas stream. The efficient and facile synthesis of Co-SSZ-13 zeolite plus its good catalytic performance might offer a good opportunity for its industrial applications in the future.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Chenxi Wang,Gang Lv,Yunqiang Li,Ye Liu,Chonglin Song
The selective catalytic reduction of nitrogen oxides by methane (CH 4 /NO X -SCR) is a potential technique for the abatement of the NO X emissions from lean-burn GDI engines, due to the excellent thermal stability of CH 4 . This work focuses on the promotion of In/SSZ-13 catalysts by Ce modification for the CH 4 /NO X -SCR performance at high temperatures. A series of In/SSZ-13 and Ce-In/SSZ-13 catalysts were prepared using the wetness impregnation method. The effects of Ce modification on the catalytic performance were analysed in detail using the scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectrum and temperature-programmed desorption/reduction techniques. The results show that the Ce modification significantly enhances the high-temperature activity of the In/SSZ-13 catalysts for the NO X -SCR reaction, especially for the 5 wt% Ce-15 wt% In/SSZ-13 sample which has more than 75% NO X conversion at 390–700 °C. In addition, the Ce modification enhances the water vapor tolerance of the catalyst sample. The Ce modification increases not only the concentration of surface chemisorption oxygen species, but also the relative amount of InO + species which serve as the main active sites for CH 4 activation. Furthermore, the incorporation of Ce into In/SSZ-13 greatly promotes NO X adsorption on the catalyst surface. Most importantly, the Ce modification makes In species well-dispersed on the catalyst surface and thus suppresses the formation of bulk In 2 O 3 species which are more active for the CH 4 non-selective oxidation. The combination of all these effects results in the Ce-In/SSZ-13 samples with the superior catalytic activity .
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Liancheng Bing,Zan Sun,Shuaiguo Zhang,Baoyu Chen,Hongxia Zhang,Min Wang,Changqing Chu,Dezhi Han,Jiankang Zhang,Fang Wang,Guangjian Wang
Direct dehydrogenation of propane to propylene (PDH) is a promising route to meet the ever-growing global propylene demand, but the industrial Pt-based catalysts usually suffer from serious deactivation derived from coke deposition and sintering under harsh reaction conditions. In this work, PtZn bimetallic nanoparticles encapsulated into high-silica SSZ-13 zeolites (PtZn@SSZ-13) were synthesized via a facile ligand-protected interzeolite transformation strategy. In a PDH reaction, the synthesized 0.5Pt3Zn@SSZ-13 catalyst exhibits superior catalytic performance with a propane conversion of 23.7% and a propylene selectivity of 96.8%, which is significantly better than that of PtZn supported on high-silica SSZ-13 (0.5Pt3Zn/SSZ-13). Particularly, the high catalytic activity of this catalyst can be kept during three successive oxidation–reduction cycles. Detailed characterizations including HAADF-STEM, XPS, UV–Vis, H 2 -TPR reveal that the remarkable improvement of PDH performance is attributed to the PtZn synergistic effect as well as the confinement of SSZ-13 zeolites. The DFT calculations and microkinetic simulations also evidenced that the Pt particles anchored on the Zn-doped SSZ-13 zeolite pore framework possessed obviously higher propane dehydrogenation activity, whereas the anti-coking ability of 0.5Pt3Zn@SSZ-13 was also stronger than Pt (1 1 1) surface, demonstrating the superior performance of 0.5Pt3Zn@SSZ-13.
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
FUEL
·
2024
·
IF 6.7
Zongyang Zhang,Yuping Li,Ze Chen,Fuchao Ji,Xiaohong Liang,Haicheng Xuan,Lina Han,Peide Han
Developing an economical and high-efficiency synthesis pathway of SSZ-13 zeolite is of great significance for the ammonia selective catalytic reduction of nitrogen oxides (NH 3 -SCR of NO x ) reactions. Herein, SSZ-13 zeolite were synthesized using L zeolite as the aluminum source in the presence of a mixed structure directing agent (SDA) composed of N,N,N, trimethtyl-1-adamantammonium hydroxide (TMAdaOH) and tetraethylammonium hydroxide (TEAOH). This synthesis strategy aims to accelerate the crystallization rate through interzeolite transformation, while less expensive TEAOH can play a cooperative structure-directing role, thus reducing the consumption of expensive TMAdaOH template. The results showed that pure SSZ-13 zeolites with high crystallinity can be obtained from L zeolite within 12 h at 160 ℃ under low TMAdaOH/SiO 2 ratio of 0.05 (too low to carry out the synthesis on its own in the current synthesis system) in the presence of TEAOH. Moreover, the crystallization mechanism was also investigated by XRD, FT-IR, SEM and TG-DTG techniques. It was proposed that the crystallization of SSZ-13 occurs through the formation of SSZ-13 nuclei under the direction of TMAdaOH and promotion of TEAOH, subsequently TMAdaOH was incorporated in the framework to further induce the crystal growth of SSZ-13. Especially, the zeolite crystal size can be modulated by the amount of TEAOH added. In addition, After Cu 2+ exchange, the obtained Cu-SSZ-13 sample exhibits superior catalysis performance in the NH 3 -SCR of NO x reaction, and the NO x conversion rate remained over 90 % across a broad range from 200 to 600 °C, demonstrating its significant application potentials in NO x removal from diesel vehicle exhausts.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
PETROLEUM CHEMISTRY
·
2022
·Vol. 62
·期 8
·962-971
·
IF 1.258
Hao Zongyi,Niu Li,Long Xuefeng,Li Hongwei,Wang Dongliang,Ji Dong,Zhao Xinhong
Abstract Two different seed crystals (K–CHA and nano-scaled SAPO-34) were used to promote the rapid interzeolite conversion of USY and fumed silica to pure SSZ-13 zeolite phase via a grinding route. The results show that both seeds can shorten the crystallization time of SSZ-13 zeolite to 24h, which is much shorter than the syntheses in the absence of seeds. The phase purity, morphology, textural parameters, elemental compositions and acid properties of two typical H–SSZ-13 samples with seeds were analyzed by XRD, SEM, N 2 physisorption, EDS and NH 3 –TPD techniques in detail, and compared with the sample without seeds and a reference sample. The results indicate that the introduction of seeds can effectively modify the acid properties of H–SSZ-13, especially their medium strong acid sites. The methanol-to-olefins (MTO) reaction was employed as a probe to evaluate the catalytic stability of above four H–SSZ-13 catalysts. The results reveal that the catalytic lifetime of the two catalysts using seeds is much longer than that of the one without seeds and the reference sample H–SSZ-13–RS. It was speculated that the appropriate concentration of medium strong acid sites may play a pivotal role in prolonging their catalytic lifetime. Here our findings may throw light on the rational design of long-lifetime H-SSZ-13 catalysts in the MTO reaction.
研究领域:
化学工程
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Yichang Yang,Xiangyu Meng,Longfeng Zhu,Jinghuai Yang,Guoliang Zhang,Hongxia Shen,Xuebo Cao
Rapid synthesis of Si-rich (SiO2/Al2O3 > 100) SSZ-13 zeolite under fluoride-free conditions is highly desirable but still challenging. Herein, we for the first time report a rapid synthesis of all silica and aluminosilicate (SiO2/Al2O3 > 100) SSZ-13 zeolite without the addition of fluoride species. The crystallization could be fully completed at 160 °C for 4 h when the aging of the starting gel is 3 h at room temperature after the addition of a zeolite seed. The key to success is the formation of more basic building units (4- and 6-membered rings) in the initial gel with the aging time of 3 h after the addition of a zeolite seed, leading to the successful rapid synthesis of Si-rich SSZ-13 zeolite. The obtained Si-rich SSZ-13 zeolite displays high crystallinity, uniform cubic morphology with a nanoparticle feature, and a large surface area. More importantly, the obtained Si-rich SSZ-13 zeolite displays excellent performance in the adsorption of ethanol and methanol-to-olefin reaction.
研究领域:
材料科学
·
化学工程
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）