FUEL
·
2021
·
IF 6.609
Tao Pan,Sida Ge,Mengnan Yu,Yana Ju,Ran Zhang,Pei Wu,Kuanyu Zhou,Zhijie Wu
Zn modified ZSM-5 zeolite supported Ni bifunctional catalysts were prepared by in-situ hydrothermal synthesis (Zn-Ni-ZSM-5), co-impregnation method (Zn-Ni/ZSM-5) as well as combining in-situ hydrothermal synthesis of Zn-ZSM-5 and sequential impregnation of Ni (Ni/Zn-ZSM-5) and used for the selective converting olefin to aromatics applicable for FCC gasoline hydro-upgrading. The Lewis (L) acid sites generated by ZnOH + species and hydrogenation active sites from Ni 0 species were varied with preparation method, in which their locations at the external surface or micropores of zeolite changed the acid properties of catalysts. Comparing to the Zn-Ni/ZSM-5 from the co-impregnation method, direct in-situ hydrothermal method could incorporate Zn and Ni species within zeolite, which makes the strong interaction between the metal species and the framework Al to form medium-strong L acids (ZnOH + /NiOH + ). This leads to the decrease of ratio of Brønsted acid sites to L acid sites (B/L) from 0.40 to 0.12 and the difficulty in reducing of Ni cations to Ni 0 from 57% to 30% Ni 0 percent. Ni/Zn-ZSM-5 sample prepared by incorporating Zn species into micropores and sequential depositing Ni species at the external surface of zeolite possesses a low B/L ratio similar to Zn-Ni-ZSM-5 (0.20 versus 0.12) but a much higher Ni 0 percent (52% versus 30%). Zn-Ni-ZSM-5 shows closer intimacy between Zn and Ni species comparing to Zn-Ni/ZSM-5 and Ni/Zn-ZSM-5. For the 1-hexene aromatization, the formed iso -alkene at acid sites was quickly saturated to iso -alkanes by the adjacent Ni 0 particles over Ni-Zn-ZSM-5 catalyst in hydrogen steam. However, the location of aromatization active sites (ZnOH + , L acid sites) in micropores and hydrogenation active sites (Ni 0 species) on external surface of Ni/Zn-ZSM-5 makes the tandem conversion of n-alkene → iso -alkene → aromatics, rather than the n-alkene → iso -alkene → iso -alkane. Thus, Zn-Ni-ZSM-5 with close intimacy of ZnOH + and Ni 0 particles shows a high iso -alkane selectivity (27.9% iC 4 + ), while Ni/Zn-ZSM-5 exhibits a high aromatics selectivity (39.6 %) in the conversion of 1-hexene in hydrogen steam. Similar results have also found in the conversion of n-heptane. Here, the control of the intimacy of Zn and Ni in ZSM-5 zeolites has been realized to be a good protocol to adjust the selective conversion of olefins/alkanes to aromatics versus iso -alkanes.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Zhihong Zheng,Yi Lin,Zheyu Lin,Dacheng Zhang,Junhan Lin,Kailing Ruan,Chunxiang Lin,Xiaoxia Ye,Jie Chen
Efficient removal of p -arsanilic acid ( p -ASA) from contaminated water is crucial for mitigating arsenic contamination. In this study, a membrane adsorbent named CFM-Zn is developed by retanning Zn on a collagen fiber membrane (CFM). This development leverages the unique physicochemical properties of CFM and the strong affinity of Zn for p -ASA. The membrane is composed entirely of green, low-carbon, and recyclable materials, achieving sustainable removal of p -ASA and embodying the concept of using waste to treat waste for environmental recovery. Remarkably, it exhibits an ultra-high capacity of up to 515.46 mg·g −1 . Additionally, CFM-Zn demonstrates moderate reusability, with effectiveness maintained for at least five cycles. This study could advance the development of bio-based materials for water pollutant removal, expand the applications of leather waste, and significantly promote environmental purification and resource recycling.
研究领域:
环境科学
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材料科学
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水资源管理
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 13
·4412-4423
·
IF 5.721
Qiang Liu,Zhenbo Zhao,Masahiko Arai,Chao Zhang,Ke Liu,Ruhui Shi,Peixuan Wu,Zhuangqing Wang,Weiwei Lin,Haiyang Cheng,Fengyu Zhao
The transformation of γ-valerolactone (GVL) into 1,4-pentanediol (1,4-PDO) and 2-methyltetra-hydrofuran (2-MTHF) in the presence of H2, one of the useful biomass conversion and utilization processes, was investigated with monometallic Cu/Al2O3 and bimetallic ZnCu/Al2O3 catalysts. A 10 wt% Cu-loaded monometallic catalyst produced 1,4-PDO and 2-MTHF in comparable quantities at a medium conversion (∼50%). When Zn was added in a range of Zn/Cu molar ratios of up to 2, in contrast, the catalysts yielded 1,4-PDO in a high selectivity of about 97% at low and high conversion levels. In addition, the 1,4-PDO selectivity over the ZnCu/Al2O3 catalysts remained almost unchanged during recycled runs. That is, the addition of Zn to Cu/Al2O3 switched the product selectivity and improved the catalyst stability and reusability. Furthermore, the physicochemical properties of the catalysts were characterized by several methods including XRD, TEM, TPR, XPS, FTIR of adsorbed pyridine, and so on. On the basis of those results, the relationships between the catalytic performance (activity, selectivity, and reusability) and the catalyst structural features were discussed.
研究领域:
催化化学
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生物质转化
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材料科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
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IF 4.507
Xiaoping Wu,Qiao Zhang,Lungang Chen,Qiying Liu,Xinghua Zhang,Qi Zhang,Longlong Ma,Chenguang Wang
The development of thermally stable Pt-based catalysts with superior performance for propane dehydrogenation reactions remains a daunting challenge. In this study, a series of PtSn-Mg(Zn)AlO catalysts with different Zn and Pt contents were synthesized by the anion-exchange method for the propane dehydrogenation reaction. To investigate the influence of Zn on the reaction performance and the catalyst structure, the prepared catalysts were characterized with several analytical techniques, including XRD , TEM, HRTEM, H 2 -TPD and CO pulse chemisorption . A good propane conversion (initially higher than 55% and averaging 45.2% over a period of 2 h) and propene selectivity (higher than 99%) were obtained experimentally with PtSn-Mg(3Zn)AlO at 550 °C. The results demonstrated that Pt provided the active sites and that Zn was a promoter. The HRTEM and CO pulse chemisorption results indicated that the addition of Zn to the PtSn-MgAlO catalyst can stabilize the dispersion of metal particles and thus inhibit the sintering of Pt particles. Furthermore, the activities of the used catalysts were almost recovered through reaction-regeneration cycles with the burning-off of coke during five cycles.
研究领域:
催化
·
化工
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）