JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Kunli Song,Shuqi Zhao,Zhenguo Li,Kaixiang Li,Yurong Xu,Yijun Zhang,Yonghong Cheng,Jian-Wen Shi
SSZ-13 has been commercialized as a catalyst in diesel engines for the selectivity catalytic reduction of nitrogen oxides (NO x ) with ammonia (NH 3 -SCR), but the catalyst is facing the problem of poisoning. Herein, two well-designed catalysts, Cu-SSZ-13 and cerium (Ce) doped Cu-SSZ-13 are synthesized, and their tolerance to zinc (Zn) and phosphorus (P) poisoning alone and together are explored in detail. The research found that Zn and P poisoning alone leads to the destruction of Cu-SSZ-13 structure, resulting in the decline of denitration (de-NO x ) performance following the mechanism dominated by Eley-Rideal (E-R). Surprisingly, it is found that zinc phosphate particles are formed at inactive sites on the surface of Cu-SSZ-13 in the presence of Zn and P together, which protects the active sites, enhances the adsorption of nitric oxide. As a result, the excellent de-NO x performance of Cu-SSZ-13 is well maintained following the dual mechanism of E-R and Langmuir-Hinshelwood (L-H). In addition, the introduction of Ce stabilizes the active sites, so as to improve the de-NO x performance and the poisoning tolerance of Cu-SSZ-13. This work deeply analyzes the reasons of Zn and P poisoning and the positive effect of Ce on Cu-SSZ-13, which provides ideas for improving the poisoning tolerance of Cu-SSZ-13 and promotes the further application.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
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
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
TOPICS IN CATALYSIS
·
2024
·
IF 2.8
Wang Xinyu,Xu Xin,Xiong Wuwan,Ye Daiqi,Chen Peirong
Catalytic oxidation is an effective solution for the control of methane (CH 4 ) emission in exhausts from natural gas vehicles. Pd-based small-pore zeolites (such as Pd-SSZ-13) are considered to be the most active catalysts for CH 4 oxidation, but H 2 O in the exhausts tends to induce deactivation of Pd catalysts. In this work, we tuned the hydrophobicity of Pd-SSZ-13 as a representative to improve its H 2 O resistance in CH 4 oxidation. Pd-SSZ-13 catalysts with different Si/Al ratios were obtained by dealuminizing the pristine SSZ-13 zeolite with acid followed by Pd ion exchange, and a reduction of T 50 (i.e. the temperature to reach 50% conversion of CH 4 ) by 20 ℃ was achieved in CH 4 oxidation in the presence of 10 vol.% H 2 O. Detailed physicochemical characterizations showed that the fraction of highly dispersed PdO species (highly active in CH 4 oxidation) increased, whereas that of less inactive PdO x clusters decreased, in the Pd-SSZ-13 after acid modification. In addition, the increase of zeolite hydrophobicity after acid modification alleviated the H 2 O inhibition effect on the active PdO phase, leading to a less activity loss of Pd-SSZ-13 in CH 4 oxidation. The improved hydrophobicity also favored C 3 H 8 combustion over Pd-SSZ-13. These results suggested that simple acid modification could tune effectively the Si/Al ratio and hydrophobicity of zeolite supports, and eventually the physicochemical properties and oxidation performance of the supported Pd catalysts.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Zhikang Xu,Mingbin Gao,Xing Wu,Haibo Zhu
Pt-Cu bimetallic particles have been regarded as promising catalysts for propane dehydrogenation. The dispersion of Pt and Cu species on conventional supports always results in the formation of large Pt-Cu particles, and it is highly desirable to fabricate ultra-small Pt-Cu cluster catalysts for propane dehydrogenation. Herein, we used the isolated Cu species in the Cu-SSZ-13 to localize the Pt species and the alloying of Pt with Cu leads to a formation of ultra-small (<1 nm) Pt-Cu bimetallic clusters in the structure of SSZ-13. The structure of synthesized PtCu-SSZ-13 catalysts was studied by XRD, SEM, STEM, XPS, CO-FTIR, H 2 -TPR and EXAFS techniques, which demonstrates that Pt-Cu clusters are entrapped in the micropore of SSZ-13 and their migration can be greatly inhibited. The synthesized PtCu-SSZ-13 catalyst shows high activity and good regeneration in propane dehydrogenation. The optimized catalyst 0.3 %PtCu-SSZ-13 delivers propane conversion of 28.5 % (close to equilibrium conversion) with 100 % propane as feed under WHSV of 7.1 h −1 at 520°C, and its catalytic performance can be completely regenerated via calcination in air. Density functional theory (DFT) calculations indicate that the unique Pt-Cu bimetallic nanocluster structure reduces the energy potential for propane dehydrogenation as well as promotes the adsorption of C 3 H 8 and desorption of C 3 H 6 thus enhancing the activity of the PtCu-SSZ-13 catalyst.
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
MICROPOROUS AND MESOPOROUS MATERIALS
·
2025
·
IF 4.7
Weibo Chen,Feng Ye,Shuanshi Fan,Yanhong Wang,Xuemei Lang,Zijian Zhang,Gang Li
Manipulating pore structures with precisely controlled pore sizes and surface chemistry is essential for fabricating high-quality zeolite membranes. This study aims to improve the performance of SSZ-13 membranes by tuning their pore structures using an occluded organic structure-directing agent (OSDA) through low-temperature hydrocracking. The resulting membranes demonstrated notable improvements in H 2 /CO 2 separation. Permeation tests indicated that the SSZ-13 zeolite membrane achieved a moderate H 2 permeance of 1.04 × 10 −7 mol Pa −1 m −2 s −1 , along with a markedly improved H 2 /CO 2 ideal selectivity of 225 at 150 °C. Both H 2 and CO 2 permeances increased significantly through the membrane with increasing temperatures, suggesting an activated diffusion mechanism for their permeation. The activation energy for H 2 permeation was calculated to be as high as 8.98 kJ mol −1 , suggesting that the membrane has a relatively small mean pore size and minimal defects. CO 2 adsorption and temperature-programmed desorption (TPD) analysis showed a pronounced interaction between CO 2 molecules and the SSZ-13 membrane, likely accounting for the exceptionally low CO 2 permeance observed. These SSZ-13 zeolite membranes demonstrate considerable potential for efficient H 2 /CO 2 separation in practical applications.
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
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 27
·15238-15245
·
IF 12.732
Linying Wang,Dali Zhu,Juan Wang,Wenhao Cui,Jingfeng Han,Bing Li,Dong Fan,Peng Tian,Zhongmin Liu
An X-ray amorphous material with a CHA-like structure, named embryonic CHA zeolite, has been designed and employed for the synthesis of SSZ-13, which leads to ultra-fast crystallization (1.5–12 h), wide product SiO2/Al2O3 ratio (SAR = 22–100) and high yield (82.8–92.9%). The usage of N,N,N-trimethyl-1-adamantammonium hydroxide (TMAdaOH) for the synthesis can be controlled at unprecedentedly low amounts (TMAdaOH/SiO2 = 0.035–0.050). Characterization results reveal that the embryonic zeolite has a small particle size of 10–20 nm, large micro/mesopore volume and abundant double 6-ring units (subunits of the CHA structure). It provides ample active surface and subunits for the formation of the CHA structure and promotes the fast synthesis of SSZ-13 with a wide phase region. The resultant material (SAR = 23.2), after Cu2+ exchange, exhibits superior NH3-SCR activity and extraordinary hydrothermal stability (steaming at 800 °C for 16 h), implying its promising application for NOx removal. In addition, high-silica SSZ-13 shows good catalytic performance for the MTO reaction. It is anticipated that the embryonic zeolite-assisted strategy will benefit the synthesis of more industrially important zeolites.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jingang Wang,Jianbo Zhang,Cheng Xing,Taosheng Jin,Jinpeng Liu,Meiting Ju,Xuejiao Tang
Phosphorus (P) poisoning of NH 3 -SCR catalysts is inevitable in application of NO x abatement of diesel exhaust. The distinct effects on Cu-SSZ-13 of P from different precursors (H 3 PO 4 and (NH 4 ) 2 HPO 4 ) were figured out and the mechanism was further investigated. P-poisoned Cu-SSZ-13 (Si/Al = 6) catalysts were prepared and characterized using N 2 adsorption, X-ray powder diffraction (XRD), scanning electron microscope with energy-dispersive X-ray spectroscopy mapping (SEM-EDX), ammonia temperature-programmed desorption (NH 3 -TPD), X-ray photoelectron spectroscopy (XPS), hydrogen temperature programmed reduction (H 2 -TPR), electron paramagnetic resonance (EPR) and 27 Al solid-state magic angle spinning nuclear magnetic resonance spectroscopies ( 27 Al NMR). Significant enhancement of high-temperature activities (400–600 °C) were observed for the catalysts with P loading of 0.3–0.9 wt%, since the appropriate incorporation enabled to bind P atoms to CuO x in remained framework. However, the high P content of 1.5 wt% resulted in a detrimental effect on framework to induce the accumulation of Cu species. Interestingly, the dominant P from H 3 PO 4 was inclined to directly attack the framework Al leading to more severe dealumination, while the P from (NH 4 ) 2 HPO 4 interacted with Cu 2+ to form copper phosphate with more Cu 2+ migrating to the surface of the catalyst which promoted the NO x conversation at each active site resulting in the low-temperature catalytic activity unchanged. So, control of the P/Cu and form of P is capable of preventing P poisoning and unlocks the potential of Cu-SSZ-13 in exhaust treatment.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Qikai Ren,Shuaishuai Wang,Haoyu Liu,Xing Zhang,Yanran Cui,Gui-Rong Zhang,Lei Nie,Donghai Mei
The dry reforming of methane (DRM) serves as a pivotal reaction for hydrogen generation and the simultaneous conversion of methane and carbon dioxide, two major greenhouse gases, into syngas that can further be converted into high-value fuels and chemicals. However, catalyst deactivation imposes a major challenge that prohibits the market penetration of DRM. Here we reported a series of bifunctional Ni-Ce catalysts supported on SSZ-13 (Ni-Ce-SSZ-13) and discovered that a small amount of Ce could significantly enhance the activity, selectivity, and stability for DRM. Optimal ratio of Ni to Ce has been identified to yield peak catalytic performance. The optimal performance is correlated with the maximum Ce 3+ /Ce 4+ ratio as revealed by XPS analysis, which implies an increased presence of oxygen vacancies in the catalysts. It played a crucial role in facilitating the oxidation of activated CH 4 species at Ni sites, thereby enhancing DRM activity and diminishing the detrimental coke formation. It is also disclosed that integrating proper amount of Ce fosters its interactions with Ni, effectively preventing the agglomeration of Ni sites. This work presents great implications for the rational design and catalytic synergy of bi-/multi-functional zeolite catalysts for other technological applications.
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
Catalysis Science & Technology
·
2021
·Vol. 11
·期 22
·7467-7474
·
IF 6.119
Yangfan Ming,Gang Li
When Cu–TEPA (Cu2+ coordinated with tetraethylenepentamine) is used as a template in the one-pot synthesis of Cu–SSZ-13, Cu2+ will be reduced to Cu0, resulting in a too high Cu content in the product. Herein, by adding iron complexes to the precursor, the reduction of Cu2+ could be inhibited and FeCu–SSZ-13 samples with rational Cu and Fe contents were prepared by a simple one-pot strategy. Although these samples show high activity in the NH3-SCR at low temperature, their high temperature performance is poor due to the lack of strong NH3 adsorption sites such as Brønsted acid sites. Meanwhile, different iron complexes were used as iron sources to synthesize FeCu–SSZ-13, and among them the sample with sodium nitroprusside shows the highest activity. Due to the large ionic radius of K+, it is easily retained which blocks the pores, so the performance of the samples synthesized with a K-type iron source is poorer than that of their Na-type counterparts. Moreover, the activity of the catalyst synthesized with an Fe3+ source is higher than that synthesized with an Fe2+ source because the valence state of Fe sources has a great influence on the Fe chemical state in the catalysts.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Dongdong Chen,Huarong Lei,Wuwan Xiong,Ying Li,Xiang Ji,Jia-Yue Yang,Baoxiang Peng,Mingli Fu,Peirong Chen,Daiqi Ye
Phosphorus (P) originating from lubricant oil additives or biofuels is an emerging chemical poison in catalytic systems for automotive exhaust after-treatment. Here, we demonstrate that P-poisoning led to severe deactivation of small-pore Pd-SSZ-13 zeolites (with CHA framework) as passive NOx adsorbers (PNA) and CO oxidation catalysts for cold-start exhaust purification applications. Deactivation mechanisms of P-poisoning were unraveled by comparatively examining the P-free and P-loaded Pd-SSZ-13 zeolites using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), temperature-programmed reduction by hydrogen (H2-TPR), CO pulse adsorption, temperature-programmed desorption using NH3 as a probe molecule (NH3-TPD), ultraviolet/visible light (UV/vis) spectroscopy, and in situ diffuse relectance infrared Fourier transform spectroscopy (DRIFTS). The loss of isolated Pd sites─namely, [Pd(OH)]+ and Pd2+ (located in the eight- and six-membered rings of CHA framework, respectively)─was revealed to be largely responsible for the deactivation of Pd-SSZ-13 in passive NOx adsorption and catalytic CO oxidation. In situ DRIFTS studies using NO or CO as a probe molecule suggest that [Pd(OH)]+ was more susceptible to P-poisoning than Pd2+. Specifically, P-poisoning led to a migration of [Pd(OH)]+ from cationic exchange sites to the zeolite surface, forming inactive metaphosphate (i.e., [Pd(OH)]+PO3–) and bulk PdOx species at high temperatures. In contrast, P-poisoning of Pd2+ sites proceeded via a sequential transformation to [Pd(OH)]+ first, and then to [Pd(OH)]+PO3– and bulk PdOx. This study provides a comprehensive mechanistic understanding on the deactivation of Pd-SSZ-13 by P-poisoning, and may guide the design of high-performance, phosphorus-resistant Pd-zeolite catalysts for cold-start exhaust after-treatment.
研究领域:
催化材料
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Yinan Wang,Xuteng Zhao,Ting Chen,Zuwei Zheng,Rijing Zhan,He Lin
Pd/SSZ-13 with different Al distributions were hydrothermally synthesized and utilized as passive NOx adsorbers (PNA). The characterization results indicated that more concentrated Al distribution can not only improve the ion-exchanged level of Pd but also generated more Z 2 Pd 2+ sites at six-member rings. Thus, as revealed by NOx adsorption experiments, samples with more Z 2 Pd 2+ sites showed high NOx storage capacity as well as stronger water resistance. Besides, 84.8 % adsorption capacity of this sample was retained after hydrothermal aging treatment. On the other side, Pd existed as [Pd(OH)] + sites on SSZ-13 with isolated Al as the majority. These sites were vulnerable to H 2 O and less stable. Seriously Pd agglomerated was observed on the aged Pd/SSZ-13 with less paired Al. This study revealed that proper Al distribution on SSZ-13 could significantly improve the performance and stability of the catalyst and provided a new direction for the design of PNA catalysts.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）