INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Jinfeng Chen,Qingze Zhang,Yuanhong Zhong,Zhaoying Wang,Yakun Guo,Ming Sun,Lin Yu
To address the limitations of molecular sieves and metal oxides in the NH3-SCR of NOx, we synthesized a novel hybrid catalyst by integrating FeNbCe metal oxides with Cu-SSZ-13. The FeNbCe comodification significantly enhanced the low-temperature performance and sulfur resistance of Cu-SSZ-13 while maintaining 100% N2 selectivity across a broad activity window. The incorporation of Fe, Nb, and Ce reduced weak-acid and Lewis-acid sites while increasing strong Brønsted-acid sites, crucial for catalytic activity. The FeNbCe/Cu-SSZ-13 catalyst exhibited an enhanced surface oxygen content and redox capacity, promoting the “fast SCR” pathway and improving N2 selectivity at low temperatures. The FeNbCe oxides synergistically reacted with SO2, protecting Cu2+ active sites from sulfur poisoning and maintaining 100% NOx conversion for 4 h after SO2 introduction, maintaining 85% within 24 h. In situ DRIFTS characterization confirmed the dominance of the Langmuir-Hinshelwood (L-H) mechanism. The FeNbCe modification represents a significant advancement in the field of NH3–SCR catalysis, offering a practical and effective solution to enhance the performance of Cu-SSZ-13 while addressing key challenges such as sulfur resistance and low-temperature activity.
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DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2020
·
IF 3.104
Di Deng,Shujun Deng,Dandan He,Zhiheng Wang,Zhipeng Chen,Yi Ji,Guoping Yan,Guangjin Hou,Licheng Liu,Hong He
Ce- or La-doped Cu/SSZ-13 catalysts were prepared by a hydrothermal method and Cu, Ce or La ions were incorporated through stepwise ion exchange. The catalyst activity was measured for the ammonia selective catalytic reduction reaction. The structure and composition of catalyst were characterized by using X-ray diffraction, scanning electron microscopy, inductively coupled plasma mass spectrometry solid-state NMR, NH 3 -TPD techniques, and the active components were examined by XPS and XANES . The results indicate that the Ce and La doping can both completely preserve the SCR activity of Cu/SSZ-13 above 300 °C, but there is also a decrease of activity below 200 °C. On the other hand, Ce doping is beneficial to the formation of framework aluminum , stabilizes molecular sieve framework and Cu active sites of Cu/SSZ-13, thereby improves the catalyst hydrothermal stability. But La doping will decrease the amount of framework aluminum and Cu active sites of Cu/SSZ-13 after hydrothermally aging, even destroy zeolite CHA structure. This is quite harmful to the catalyst hydrothermal stability.
研究领域:
催化
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环境化学
·
材料科学
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DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 10
·2121-2131
·
IF 5.2
Yue Ma,Zhimin Shao,Xiaodong Wu,Yang Gao,Baofang Jin,Rui Ran,Zhichun Si,Zhenguo Li,Duan Weng
Urea is applied as an ammonia source for SCR in diesel vehicles, but incomplete urea decomposition may lead to insufficiency of NH3 and deposition of solid by-products. To improve the urea decomposition activity of Cu-SSZ-13 SCR catalysts, Cu-SSZ-13 was combined with TiO2 nanoparticles by a simple impregnation method. TiO2/Cu-SSZ-13 composites exhibited lowered decomposition temperatures of urea and related solid by-products. Thus, the composited catalysts showed higher NOx conversion and a lower amount of urea-related deposits than unmodified Cu-SSZ-13 in a simulated urea deposition scenario. The superiority of the urea decomposition activity of the composited catalysts was maintained upon 800 °C hydrothermal aging due to stabilized anatase over the catalysts according to XRD and Raman spectroscopy. H2-TPR, UV-vis, and STEM revealed the formation of Cu–Ti–O species due to Cu–Ti interactions, which was adverse to SCR activity, but no extra hydrothermal aging effect was observed on the composited catalysts compared with unmodified Cu-SSZ-13. This work showed the potential to improve the low-temperature urea-SCR performance of Cu-SSZ-13 via TiO2 modification.
研究领域:
催化
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环境科学
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材料科学
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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
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催化
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材料科学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Zhiying Liu,Meiqing Shen,Shuhuan Wang,Chunjuan Zhang,Jun Wang,Wei Li,Feng Gao
To elucidate how CeO2 additives enhance the activity and stability of Cu-SSZ-13 SCR catalysts, we investigated two CeO2/Cu-SSZ-13 composite catalysts with Cu loadings of 1.0 and 2.5 wt %. These catalysts were characterized using an array of techniques, including XRD, SEM, TEM, NMR, H2-TPR, NH3-TPD, DRIFTS, DFT and SCR reactions under both steady-state and transient kinetic analysis conditions. Our findings demonstrate that CeO2 promotes low-temperature SCR by forming exchanged, isolated Ce-ions, which enhance Cu-ion coupling efficiency. External surface CeO2 particles can convert NO + O2 to surface nitrates, but these species primarily act as spectators below ∼250 °C, and do not contribute to the enhancement of low-temperature SCR activity. In contrast, these surface CeO2 particles can synergizes with Brønsted acid sites (BAS) to elevate high-temperature SCR activity. Furthermore, hydrothermal stability and sulfur resistance are improved by the presence of external surface CeO2 particles, a benefit that applies irrespective of Cu loading.
研究领域:
催化
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环境化学
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材料科学
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物理化学
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表面科学
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Zhigang Xue,Yuan Shen,Liang Chen,Bo Liu,Na Hu,Rongfei Zhou,Weihong Xing
Pervaporation (PV) and vapor permeation (VP) using selective zeolite membranes are more energy-saving in dealing with azeotropic mixtures compared with conventional distillation for organic solvent dehydration. Herein, we developed a monolithic supported chabazite membrane and exploited its dehydration performance. The membrane was fabricated by secondary growth method on the 19-channel alumina monolithic without organic template. By finely controlling the homogeneity of nuclei growth and minimizing the intracrystalline defects through the epitaxial growth of uniformly nanosized SSZ-13 seed layer using cesium hydroxide and sodium hydroxide as cooperative hydration-mismatched inorganic structure directing agents (ISDA). The resulting monolithic chabazite membrane exhibits excellent water-perm-selectivity. The effects of feed water composition and operating temperature on the dehydration performance of the monolithic chabazite membrane were investigated through PV and VP processes. The typical membrane displayed excellent selectivities of more than 10,000 and 30,000 in 10/90 wt% water/ethanol and water/isopropanol mixtures at 393 K. The membrane exhibited excellent hydrothermal stability in a VP with a 10/90 wt% water/ethanol at 393 K for 72 h. The robust monolithic chabazite membrane with high packing density, strong mechanical strength, large membrane area and excellent water-selective performance significantly outperforms state-of-the-art membranes for dehydration in practical applications.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
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
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化学工程
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DOI
高影响因子
ChemCatChem
·
2026
·Vol. 18
·期 15
·e70966
·
IF 4.1
Fengyuan Chen,Yuwen Liu,Guoli Fan,Jianyun Bao,Minghao Zhao,Feng Li
In methanol-to-olefins (MTO) reactions, extending the catalyst lifetime remains a critical challenge for industrial applications. Herein, we develop a synergistic synthetic strategy integrating a micro-liquid film (MLF) reactor, crystal seed assistance, and ligand protection to efficiently incorporate cerium species into SSZ-13 zeolite, thereby yielding highly dispersed CeO x nanocluster-modified SSZ-13 zeolites (Ce-SSZ-13). The CeO x loading effectively modulated the acid properties by weakening Brønsted acid strength while generating additional weak Lewis acid sites. The Ce-SSZ-13 zeolite featuring a 1 wt% Ce loading showed excellent catalytic performance at a weight hourly space velocity of 1 h −1 and 400°C, with a long catalyst lifetime of 10.4 h and a 91.3% selectivity of light olefins. Notably, the catalyst lifetime was enhanced by 41.1% compared with the unmodified SSZ-13 zeolite, accompanied by a significantly reduced coke formation rate of 0.081 mg·min −1 . It was revealed that the appropriate acidity of Ce-SSZ-13 zeolites efficiently suppressed hydrogen transfer and aromatization processes in MTO reactions and stabilized key hydrocarbon pool intermediates, thereby shifting the reaction pathway toward the olefin cycle. These findings provide an effective strategy for rationally designing high-performance SSZ-13 catalysts for MTO reactions and highlight the critical role of acid modulation of SSZ-13 zeolites. Graphical Highly dispersed CeO x nanoclusters-modified SSZ-13 zeolites with tailored surface acidity were synthesized through a synergistic strategy of crystal seed assistance, ligand protection, and micro-liquid film reactor-enhanced mixing. As-synthesized modified SSZ-13 zeolites could suppress coke deposition and substantially prolonging the catalyst lifetime in the methanol-to-olefins reaction.
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DOI
高影响因子
RSC Advances
·
2026
·Vol. 16
·期 1
·383-393
·
IF 4.6
Dongdong Chen,Weiqi Zhang,Zhenzhen Jia,Huibin Liu,Bo Zhang,Shasha Liu,Feng Liang,Wuwan Xiong,Xiang Li
Pd-loaded CHA zeolites (e.g., Pd-SSZ-13) have been identified as a promising candidate for passive NOx adsorption (PNA) in low-temperature environments. The inclusion of lubricant oil additives or biofuels in automotive exhaust after-treatment systems subjects Pd-SSZ-13 to chemical poisoning from contaminants such as alkali metals (e.g., Na and K). In this study, we present a straightforward yet highly effective approach to regenerate Pd-SSZ-13 that has been poisoned by alkali metals, achieved through washing with a dilute NH4Cl solution. The underlying mechanisms of both poisoning and regeneration were thoroughly explored, revealing that the deactivation due to alkali-metal poisoning is primarily attributed to the transformation of the active Pd2+ ion into PdOx and a concomitant reduction in Brønsted acid sites. The NH4Cl washing not only removes alkali metal contaminants, thereby restoring the Brønsted acid sites previously occupied by them, but also converts the inert PdOx back into their active states (i.e., isolated Pd2+). This investigation unveils a simplified yet highly efficient NH4Cl washing technique for the regeneration of the deactivated Pd-SSZ-13, offering profound implications for extending the catalyst's lifespan and enhancing its performance in cold-start exhaust after-treatment applications.
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Wenhan Wang,Wenqiang Li,Zijian Wang,Bo Liu,Bing Wang,Jingui Duan,Rongfei Zhou
Carbon dioxide capture is an effective method to mitigate climate change . Highly CO 2 -selective and highly moisture-resistant absorbent is essential for energy-efficient carbon capture by absorption. Herein, a highly CO 2 -selective and high-silica CHA zeolite in a pure lithium form (Li-SSZ-13) was synthesized using a direct synthesis method for the first time. The effects of gel n (SiO 2 )/ n (Al 2 O 3 ) ratio, gel n (SiO 2 )/ n (Li 2 O) ratio and synthesis time on the crystallinity , yield, micropore volume and CO 2 loading of the crystals were systematically investigated. The adsorption isotherms of CO 2 and N 2 were measured for directly synthesized Li-SSZ-13, conventional Na-SSZ-13 and ion-exchanged Li-Na-SSZ-13 zeolites. The dynamic breakthrough adsorption properties were measured for Li-SSZ-13 in comparison with Na-SSZ-13 and Li-Na-SSZ-13. The obtained Li-SSZ-13 exhibited a high CO 2 adsorption capacity of 4.48 mmol/g and a high CO 2 /N 2 IAST selectivity of 310 at 100 kPa and 273 K, which were 45.0 % and 441 % higher than Na-SSZ-13 zeolite, 24.8 % and 179 % higher than Li-Na-SSZ-13 zeolite, respectively. It suggests that directly synthesized Li-SSZ-13 zeolite has great potential for efficient CO 2 capture from flue gas .
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Shuyi He,Zheguan Lin,Jie Shi,Linyu Zhou,Qingyan Cui,Tiesen Li,Jiangyong Liu,Yuanyuan Yue
For traditional strategies to construct SO 2 and H 2 O co-resistant systems in low-temperature NH 3 selective catalytic reduction (NH 3 -SCR) catalysts, the primary challenge lies in mitigating the partial loss of redox activity at active sites. Herein, we present an approach to construct a protective system based on interface engineering principles, effectively safeguarding Cu active sites in ZnO/FeCu-SSZ-13 under SO 2 and H 2 O exposure. The core innovation stems from the creation of a strong interface effect originated from Zn-O-Al bonds formed between ZnO and the framework Al on the FeCu-SSZ-13 surface. This interface effect can regulate the electronic structure of Zn O bonds on ZnO component, producing abundant basic sites around the Cu active sites, enabling the preferential adsorption of SO 2 and its oxidation into ZnSO 4 , thereby virtually eliminating the redox ability loss of Cu active sites. As a result, ZnO/FeCu-SSZ-13 achieves exceptional low-temperature NH 3 -SCR performance, maintaining over 90 % NO x conversion even in the presence of SO 2 and H 2 O. Our work opens a new avenue for developing low-temperature NH 3 -SCR catalysts with desired SO 2 and H 2 O resistance, offering valuable insights for advancing catalytic performance in challenging reaction conditions.
研究领域:
催化
·
环境化学
·
材料科学
·
表面工程
·
化学反应工程
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2026
·
IF 5.4
Dongdong Chen,Siting Hu,Zhenzhen Jia,Huibin Liu,Bo Zhang,Shasha Liu,Wuwan Xiong,Xiang Li
The integration of lubricant oil additives or biofuels compels the Passive NO x Adsorber (PNA) within automotive exhaust after-treatment systems to withstand chemical poisoning from contaminants such as phosphorus (P). For the first time, lanthanum (La) has been employed to enhance the operational efficacy of Pd-loaded small-pore SSZ-13 zeolite (i.e., Pd-SSZ-13) in the presence of phosphorus species. Our findings reveal that La modification significantly bolsters the resilience of Pd-SSZ-13 against P-induced deactivation during the cold-start phase. Furthermore, we have elucidated a pronounced reduction in the degradation of active cationic Pd 2 + ions and Brønsted acid sites within the Pd-SSZ-13 framework upon the introduction of La. Notably, La not only exerts a stabilizing influence on the framework aluminum at the Brønsted acid sites but also effectively mitigates the interaction between the active Pd 2+ species and phosphorus, thereby preventing the formation of metaphosphate and its subsequent conversion into bulk PdO x aggregates. This research offers profound insights, particularly concerning the utilization of La to augment the resistance of Pd-SSZ-13 zeolite catalysts against poisoning by various chemical poisons (such as alkali metals or sulfur) and to enhance their high-temperature hydrothermal stability.
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高影响因子
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