Catalysis Science & Technology
·
2019
·Vol. 10
·期 3
·835-843
·
IF 5.726
Yan Zhang,Shide Wu,Xia Xu,Heqing Jiang
Rapid deactivation by coke deposition is the main obstacle of ethane aromatization over Zn/ZSM-5. In this work, using the prepared nanosized Zn/HZSM-5, an almost threefold product yield and significantly improved stability were achieved in comparison with those of the microsized catalyst. XRD and XPS analyses indicated that a higher percentage of reactive [ZnOZn]2+ species was maintained during ethane aromatization over nano-Zn/HZSM-5 than micro-Zn/HZSM-5. In addition, the evolution of carbon deposits over nanosized and microsized Zn/ZSM-5 was investigated during prolonged ethane aromatization reaction using Raman spectroscopy and thermogravimetry measurements. Compared to the microsized catalyst, the nanosized zeolite facilitated the faster escape of light aromatics and the precursors of carbon deposits from the zeolite pores, thus suppressing the accumulation of coke deposits and improving the catalyst stability. Based on the nanosized Zn/HZSM-5, a protocol of isothermal reaction followed by regeneration was developed by periodically removing carbonaceous deposits, and an ∼25–35% product yield was achieved after 10 reaction–regeneration cycles.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Runze Jin,Ke Ma,Zhongshun Chen,Zhongqiang Tang,Haobin Hu,Jiaofei Wang,Zhuangzhuang Zhang,Chengyi Dai,Xiaoxun Ma
The selectivity of methanol conversion to aromatics on Zn/ZSM-5 is often limited, mainly because the hydrogen removed during the process combines with low-carbon olefin intermediates to regenerate alkanes and reduce the effective utilization of carbon atoms. Herein, CO 2 is added to the methanol aromatization reaction as a receptor that consumes hydrogen in situ, which reduces the hydrogen transfer reaction and improves the selectivity of aromatics. It is proposed that aromatic selectivity under CO 2 atmosphere is determined by the chemical state of Zn species. Specifically, ZnO converts CO 2 and consumes hydrogen, and ZnOH + promotes methanol aromatization. Under the same conditions, aromatic selectivity of 3ZnZ18-IM under CO 2 atmosphere can reach 85.2 %, which is much higher than that of 71.4 % under N 2 atmosphere. This study provides a new strategy for methanol to aromatics (MTA) reaction, which has a positive impact on solving the energy and environmental problems in the production of aromatics.
研究领域:
化学工程
·
催化科学
·
能源与环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xinhui Liu,Chen Yan,Yilin Wang,Peng Zhang,Siyan Yan,Hanbin Wang,Jianguo Zhuang,Yitao Zhao,Yuchen Wang,Yijun Yu,Qichao Zhao,Xuedong Zhu,Fan Yang
A series of Zn loaded ZSM-5 (Zn/ZSM-5) zeolites were prepared utilizing either Zn(NO 3 ) 2 or Zn-based MOFs (ZIF-61, ZIF-8 and ZIF-14) as Zn sources to explore their effects on the catalysts’ physiochemical properties through characterizations and simulations. Results revealed that hierarchical structures containing meso - to macro- pores of 10 ∼ 80 nm aside from the intrinsic micropores were constructed profiting from the use of Zn-based MOFs. On the other side, lager proportions of medium acid and Lewis acid sites were generated by more Zn(OH) + , whose content was proven to be inextricably linked to the binding energy between Zn and ligand as well as local charge valence state of Zn. Benefitting from hierarchical structures and balanced acidities, Zn/Z5(ZIF-14) employing ZIF-14 as Zn source demonstrated higher aromatic selectivity and longer catalyst lifetime (50.9 % and 26 h) than the microporous counterpart synthesized from zinc nitrate hexahydrate (42.1 % and 20 h) in methanol to aromatics (MTA) reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Zhuo Wang,Huiling Zheng,Fanhui Meng,Tingjun Fu,Zhong Li
The use of ZSM-5@Zn/ZSM-5 core@shell nanocrystals as integrated catalyst for efficient aromatic production from methanol aromatization is demonstrated. By combining the attributes associated with core@shell structural and acidic features, ZSM-5@Zn/ZSM-5 exhibited synergistic and improved catalytic performance toward methanol aromatization. The effect of Zn/ZSM-5 shell thickness and the acid density of the ZSM-5 core on synergistic performance was systematically investigated. Results showed that aromatic selectivity could be increased with shell thickness and the acid density of the ZSM-5 core, while catalytic stability was subject to the optimization on both shell thickness and core acid density. The strengthening of dehydroaromatization on the shell catalyst after Zn introduction and the hydrogen transfer for aromatization with increasing core acid density was confirmed. A double boost on catalytic stability from methanol conversion along with 40.7% increase on aromatic selectivity could be achieved for core@shell catalyst with a coating ratio of 0.3 compared with that on single core catalyst. The fabrication of ZSM-5 core with low SiO 2 /Al 2 O 3 ratio for Zn/ZSM-5 not only provided more acid sites to promote the aromatization, but also promoted the dealkylation of the formed aromatics, which could enhance the selectivity of light aromatics and catalytic lifetime. The findings in the work not only enrich the family of core@shell composite zeolite catalysts, but also provide the fundamental understanding on the aromatization process over core@shell structural features.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
AICHE JOURNAL
·
2022
·Vol. 69
·期 5
·e17974
·
IF 4.167
Hao Yan,Delun Ren,Zhiqiang Li,Junshu Chen,Xinyang Zhang,Yanhao Wang,Gongzheng Duan,Xiang Feng,Xin Zhou,Yibin Liu,Xiaobo Chen,Chaohe Yang
Engineering acid site spatial location of zeolite catalyst harbors tremendous potential to boost catalytic performance but still remains a grand challenge for aromatization reaction. Herein, we successfully manipulate acid site spatial location inside the ZSM-5 channels to promote the hexane aromatization via the simple SiO 2 coating treatment. Multi-techniques demonstrated that the medium strong L acid in the channel originated from the Si(Al) O Zn structure is mainly retained in the Zn/ZSM-5-Si catalyst by covering the acid sites outside the channel. Surprisingly, there is a good linear relationship between BTEX yield and this medium strong L acid content. Based on the reaction kinetics, in situ FT-IR and theoretical calculations, it is found that the L acid with confinement effect served as the main active site could prominently enhance the cyclization of propene intermediate and the dehydrogenation of cycloalkane due to the strong affinity between the C/H and ZnOx, and control the desorption of BTEX (mainly benzene, toluene, ethylbenzene, and p-xylene) by weakening the binding of hydrogen proton to π electrons. Compared with the ordinary Zn/ZSM-5 catalyst, the yield of BTEX is increased by nearly 10%, and the Zn/ZSM-5-Si catalyst exhibits excellent anti coking deactivation ability. This strategy together with mechanistic results may pave the rational design of efficient Zn/ZSM-5 catalysts for aromatization reaction.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2026
·
IF 5.9
Guinong Qiao,He Li,Xuejian Liu,Haoyang Zhang,Jiazhuo Song,Hamed Alshawwa,Xinying Zou,Rong Han,Wenjun Tang,Ruijing Shangguan,Wenfu Yan,Zhimin Zhang
Bio-enhanced zeolite nanoplatform (NQZ@ZSM-5) engineered for dentin interfaces. • Synergistic antibacterial, anti-degradation, and remineralization at biointerfaces. • Aged bond strength increases ~2.03× versus a commercial adhesive. • Excellent biocompatibility with preserved interfacial adhesion performance. Dentin adhesives are essential for minimally invasive restorative dentistry. However, the long-term stability of the resin−dentin interface remains limited due to collagen degradation and bacterial erosion. Achieving synergistic antibacterial activity, collagen cross-linking, and remineralization at this interface is therefore crucial for durable dentin bonding. Quercetin (QC), a natural polyphenol, possesses both antibacterial activity and collagen cross-linking capability. These properties can be further enhanced through coordination with metal ions to form metal–phenolic networks (MPNs). In this study, we used the NGV peptide, derived from bone sialoprotein (BSP, a non-collagenous protein), as a remineralization motif. We combined NGV with an MPN to construct a bio-enhanced nanoplatform (NGV/QC−Zn@ZSM-5) for dentin adhesives. The nanoplatform was prepared by incorporating Zn 2+ into ZSM 5 zeolites, followed by surface coating with a QC−Zn MPN and subsequent functionalization with NGV. ZSM-5 serves as a multifunctional carrier due to its high ion-exchange capacity, tunable surface chemistry, and ability to enable controlled Zn 2+ release. The resulting system is designed to stabilize collagen, inhibit bacterial biofilm formation, and promote dentin remineralization. This integrated strategy strengthens the resin−dentin interface against both enzymatic and bacterial degradation, thereby improving bonding durability. Notably, after aging, the modified adhesive exhibited a bond strength approximately 2.03-fold higher than that of the commercial control. Overall, these results highlight the strong potential of this nanoplatform to enhance the longevity and clinical performance of dental bonding restorations.
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Jian Zhang,Liang Wang,Zhiyi Wu,Hai Wang,Chengtao Wang,Shichao Han,Feng-Shou Xiao
We report the synthesis of Zn/ZSM-5 particles coated with a silicalite-1 zeolite shell (core–shell Zn/ZSM-5@silicalite-1) via grinding of the raw silica source materials with TPAOH and Zn/ZSM-5, followed by solvent-free crystallization at 180 °C for 72 h. The product was well characterized by the XRD patterns, N2 sorption isotherms, SEM images, and TEM images. Because of the core–shell structure, the Zn/ZSM-5@silicalite-1 sample exhibits high selectivities for benzene, toluene, and xylenes in the conversion of methanol, compared with those over ZSM-5 and Zn/ZSM-5 samples. The solvent-free synthesis offers an alternative method for preparing core–shell Zn/ZSM-5@silicalite-1 catalysts.
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
Journal of Energy Chemistry
·
2015
·
IF 2.352
Xiaodong Wang,Xiaoxia Gao,Mei Dong,Hongbin Zhao,Wei Huang
Nano hierarchical mesoporous ZSM-5 catalysts were prepared with cationic dimethyldiallyl ammonium chloride acrylamide copolymer (PDDA) as a soft second template. Using ZSM-5 catalyst as a matrix, Zn/ZSM-5 catalysts were also obtained by the wet impregnation method. The effect of the PDDA amount and Zn loadings on the properties of the catalysts, including crystallinity , morphology, textural properties, acid nature and catalytic activity in MTG reaction, was investigated by XRD , FESEM , TEM, Nitrogen adsorption–desorption isotherms and NH 3 -TPD method, respectively. The MTG reaction was performed in a fixed bed reactor , and the result revealed that the nano hierarchical ZSM-5 catalyst prepared with a PDDA/Si molar ratio of 0.070 possesses longer stable phase of 70 h with a liquid hydrocarbon selectivity of 29.8%. Zn/ZSM-5 catalyst with a Zn/ZSM-5 ratio of 0.07 wt.% shows the highest liquid hydrocarbon selectivity, reaching 62.5%.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）