ENERGY & FUELS
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2022
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IF 4.654
Jing Li,Suxia Ma,Rongji Cui,Nuo Xu,Ting Pei
Solid waste fly ash can encroach on land, contaminate the environment, and jeopardize human health. An alkali fusion method combined with a hydrothermal method was adopted to prepare fly ash-derived ZSM-5 molecular sieves, and a series of Fe/ZSM-5 catalysts were also prepared to test their catalytic performance in NO oxidation with H2O2. Moreover, the characteristics of catalysts synthesized by fly ash, as well as the relationship between the structure and the catalytic activity, were analyzed in detail through multiple characterization approaches. The results gave important insights into the active sites of catalytic oxidation. They concluded that 10% Fe/ZSM-5 had the best catalytic activity in which Fe sites and Brønsted acid sites collectively provided the catalytic functionality, and 92% NO removal efficiency was obtained achieved under optimal experimental conditions. This work provided a new way for recycling fly ash and developing low-cost catalysts for NO removal.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Qichao Lu,Jie Li,Chen Liang,Lei Liu,Jinxiang Dong
Under the dual pressures of oil depletion and low-carbon transition, Fischer-Tropsch synthesis (FTS) technology offers a viable option for producing high value-added lower (C 2 -C 4 ) hydrocarbons from non-oil sources. However, conventional Fe-based catalysts often suffer from deactivation due to carbon deposition and sintering. Here, we report a unique Fe-ZSM-5 catalyst synthesized by doping Fe into ZSM-5, which demonstrates excellent FTS catalytic performance. During high-temperature template removal, Fe species migrated from the zeolite framework to form highly dispersed FeO x clusters (∼2 nm). Upon treatment by syngas, these FeO x clusters aggregate to form uniformly small-sized Fe 5 C 2 @C core-shell particles distributed on ZSM-5 support. The confinement effect of the inter-crystalline structure effectively prevents the sintering of Fe 5 C 2 . The smaller Fe 5 C 2 particles exhibit controlled CO dissociation, reducing the concentration of activated carbon species (C*), and the carbon shells (∼6.5 nm) limit the departure of C*, effectively suppressing carbon deposition. This unique structure enables stable catalytic activity for over 100 hours with maintained product selectivity. The Fe-ZSM-5 catalyst achieved a C 2 -C 4 hydrocarbons selectivity of 54.52 %, nearing the 56 % theoretical limit of the Anderson-Schulz-Flory (ASF) distribution. Additionally, the hydrophobic carbon shell prevents excessive oxidation of Fe 5 C 2 , reducing CO 2 selectivity by ∼56 % compared to conventional Fe/ZSM-5 catalysts, significantly enhancing atomic utilization efficiency and aligning with the principles of green development.
研究领域:
化学工程
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材料科学
·
能源催化
✓ 已验证
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Yuheng Qiao,Zhenzhen Guan,Mengyan Zhang,Gan Chen,Shifeng Zhou,Hailong Liu,Jiang Wu,Ruitang Guo,Weiguo Pan,Fangqin Li,Ping He
In this paper, a series of Fe-based catalysts with Zeolite Socony Mobil-5 (ZSM-5) as supports were synthesized using the sol–gel method to obtain the Fe/ZSM-5, Mn-Fe/ZSM-5, Cu-Fe/ZSM-5 and Cu-Mn-Fe/ZSM-5 catalysts. The synthesized catalysts were examined and characterized via catalytic activity testing, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N 2 adsorption/desorption, scanning electron microscope (SEM), temperature-programmed desorption of NH 3 (NH 3 -TPD), temperature-programmed reduction with H 2 (H 2 -TPR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results showed that the Cu-Mn-Fe/ZSM-5 catalyst had the best catalytic performance compared with the other catalysts. In addition, Fe/ZSM-5 and Cu-Mn-Fe/ZSM-5 all exhibited excellent stability as well as good tolerance to SO 2 & H 2 O under the experimental conditions. Further characterization results showed that with co-doping of Cu and Mn, the amount of Mn 4+ , Cu + , Fe 3+ and surface chemisorbed oxygen (O β ) on the surface of Fe/ZSM-5 increased, promoting the catalytic performance. The DRIFT studies revealed that the NH 3 -SCR reaction followed both the E-R and L-H mechanism on the surface of the Fe-based ZSM-5 catalyst. The Fe-based ZSM-5 catalyst is a good candidate for NH 3 -SCR both in high reactivity and outstanding stability.
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
CHEMOSPHERE
·
2019
·
IF 5.108
Ruijie Xie,Gaoyuan Liu,Dingping Liu,Shimin Liang,Dongxue Lei,Hanying Dong,Haibao Huang,Dennis Y.C. Leung
The traditional treatment processes for volatile organic compounds (VOCs) removal generally suffered several disadvantages, such as secondary air-pollutants. To overcome these issues, wet scrubber coupled with heterogeneous UV/Fenton was developed for gaseous VOCs (i.e. toluene) removal. ZSM-5 supported iron oxide (Fe/ZSM-5) was prepared as a multifunctional catalyst for activation of H 2 O 2 and enhancement of gas-liquid mass transfer. Toluene was removed efficiently by this coupled process with the removal efficiency of 85% during 120 min. Many intermediates were detected in the solution by GC-MS while no intermediates were observed in the outlet gas, suggesting that wet scrubber coupled with heterogeneous UV/Fenton could significantly reduce secondary air pollutants . The possible mechanism of toluene oxidation was proposed including the physical adsorption by Fe/ZSM-5 and OH oxidation. This study provides an environmentally benign and highly efficient chemical scrubbing process for gaseous VOCs removal.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2025
·
IF 7.5
Xiaohui Wang,Zhilong Cheng,Bingrong Liu,Huiyi Liu,Xin Fang,Ruiqi Chai,Lishuang Ma,Yuchao Lyu,Jianye Fu,Xinmei Liu
Methane dehydroaromatization (MDA) was a promising technology for the synthesis of high value-added aromatics through natural gas. Fe/ZSM-5 catalysts were widely used in MDA reaction. However, its catalytic mechanism remained ambiguous. In this work, a novel one-pot strategy was developed for the preparation of Fe/ZSM-5 catalysts, which can delicately control the iron species and acidic property of Fe/ZSM-5 catalysts. In-situ DRIFTS and DFT calculation demonstrated that MDA followed a bifunctional mechanism and the second C–H bond breaking process of CH 4 was the rate-determining step, where methane underwent coupling and dehydrogenation at the iron active sites to generate intermediate species (ethylene), and Brønsted acid sites played a key role in determining the selectivity of aromatics. Moreover, CO-pulse chemisorption revealed the quantitative synergistic effect between metal active sites and Brønsted acid sites. Catalysts with highly dispersed iron oxide and proper density of Brønsted acid sites exhibited the best catalytic performance. This study elucidated the catalytic roles of iron species and Brønsted acid sites in Fe/ZSM-5 catalysts in MDA and provided guidance for the future development of highly active MDA catalysts.
✓ 已验证
产品关联
DOI
高影响因子
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