ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2024
·Vol. 31
·期 13
·19738-19752
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IF 0
Tian Kun,Pan Jie,Liu Yun,Wang Ping,Zhong Ming,Dong Yuanhua,Wang Meng
Heterogeneous Fenton oxidation using traditional catalysts with H 2 O 2 for the degradation of 1,4-dioxane (1,4-DX) still presents challenge. In this study, we explored the potential of Fe-ZSM-5 zeolites (Fe-zeolite) with three Si/Al ratios (25, 100, 300) as heterogeneous Fenton catalysts for the removal of 1,4-DX from aqueous solution. Fe 2 O 3 or ZSM-5 alone provided ineffective in degrading 1,4-DX when combined with H 2 O 2 . However, the efficient removal of 1,4-DX using H 2 O 2 was observed when Fe 2 O 3 was loaded on ZSM-5. Notably, the Brønsted acid sites of Fe-zeolite played a crucial role during the degradation of 1,4-DX. Fe-zeolites, in combination with H 2 O 2 , effectively removed 1,4-DX via a combination of adsorption and oxidation. Initially, Fe-zeolites demonstrated excellent affinity for 1,4-DX, achieving adsorption equilibrium rapidly in about 10 min, followed by effective catalytic oxidative degradation. Among the Fe-ZSM-5 catalysts, Fe-ZSM-5 (25) exhibited the highest catalytic activity and degraded 1,4-DX the fastest. We identified hydroxyl radicals (·OH) and singlet oxygen ( 1 O 2 ) as the primary reactive oxygen species (ROS) responsible for 1,4-DX degradation, with superoxide anions (HO 2 · /O 2 · − ) mainly converting into 1 O 2 and ·OH. The degradation primarily occurred at the Fe-zeolite interface, with the degradation rate constants proportional to the amount of Brønsted acid sites on the Fe-zeolite. Fe-zeolites were effective over a wide working pH range, with alkaline pH conditions favoring 1,4-DX degradation. Overall, our study provides valuable insights into the selection of suitable catalysts for effective removal of 1,4-DX using a heterogeneous Fenton technology.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
PubMed
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Meihua Zhu,Shiming Huang,Yudan Gong,Yunyan Zhou,Xinyu Chen,Yongsheng Liu,Na Hu,Fei Zhang,Xiangshu Chen,Hidetoshi Kita
Good separation performance NaY zeolite membrane was successfully prepared on the tubular mullite support by fluoride-containing precursor synthesis gel. The fluoride source had a great influence on NaY zeolite membrane growth and separation performance for EtOH/ETBE mixture, the NaF containing precursor gel was benefit for preparing high Si/Al ratio, fine reproduction quality and long-term stable NaY zeolite membrane. Solid state 19 F MAS NMR characterization results indicated that the fluorine existed in the channel of NaY zeolite crystals. Both flux and separation factor of the NaY zeolite membrane were greatly depended on the separation temperature and composition of EtOH/ETBE mixtures. The NaY zeolite membrane presented eminent long-term stability for separating 20 wt% EtOH/ETBE mixture at 60 °C, even if the test time was prolonged to 80 h, the flux and separation factor were kept 1.30 kg m −2 h −1 and 1100.
研究领域:
材料科学
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膜分离技术
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化学工程
·
无机非金属材料
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功能材料
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2025
·
IF 3.9
Zhouxiao Zhai,Jingce Bi,Yi Wang,Ningning Liu,Linshan Wang,Xia Zhang,Zhuopeng Wang,Yide Han
Graphical In this work, a mesoporous molecular sieve with graphite carbon-coated Co NPs (Co@CN/Al-MCM-41) was successfully synthesized by vacuum-injecting the precursor solution into the MCM-41 molecular sieve and subsequent calcination. Experimental results demonstrate that Co@CN/Al0.1-MCM-41 exhibits excellent catalytic performance in the hydrogenation of FF. Its excellent catalytic performance is primarily attributed to the interaction between Co species and Al species of MCM-41, including the reduction effect, electron transfer, and enhancement of acid density. The catalytic hydrogenation of furfural (FF) to furfuryl alcohol (FOL) using metal-loaded mesoporous molecular sieves represents a significant research area. In this work, a mesoporous molecular sieve with graphite carbon-coated Co NPs (Co@CN/Al-MCM-41) was successfully synthesized by vacuum-injecting the precursor solution into the MCM-41 molecular sieve and subsequent calcination. Using Co@CN/Al 0.1 -MCM-41 as the catalyst, the selective hydrogenation of FF to FOL achieved a conversion rate of 91.2% under mild conditions at 120 °C, which is 2.85 times higher than that of Al-free Co@CN/MCM-41, with an FOL selectivity of 97.2%. The experimental results revealed a strong correlation between FF conversion and the Si/Al ratio of MCM-41 molecular sieve. Increasing the Al species content facilitated the formation of more Co NPs active sites because of the strong electrostatic interaction, thereby promoting the activation of FF and hydrogen and enhancing the catalytic activity of Co@CN/Al 0.1 -MCM-41. Additionally, Co@CN/Al 0.1 -MCM-41also exhibited stable performance over five consecutive cycles, which was attributed to the formation of graphite carbon-coated Co NPs structure during the synthesis process. This simple fabrication strategy provides a novel approach for the modification of mesoporous molecular sieves with excellent catalytic activities.
研究领域:
催化化学
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材料科学
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化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Xiaohong Yao,Jian Zhang,Chao Long
This study explored how the Si/Al ratio in Nb-Mn/MCM-41 catalysts affect toluene degradation via plasma catalysis. Adjusting the Si/Al ratio altered catalyst acidity and redox properties, decreasing the Si/Al ratio led to increased acidity, higher Mn 3+ /Mn 4+ ratio and greater O ads /O lat ratio as indicated by NH 3 -TPD, XPS, and O 2 -TPD analysis. Lower Si/Al (Nb-Mn/M(25)) boosted toluene removal efficiency to 98.2% under dry conditions due to increased oxygen vacancies and acidity. Moderate humidity enhanced conversion, but higher humidity levels proved detrimental, especially for low Si/Al catalysts. At a humidity level of 3.11 vol%, the toluene removal efficiency of Nb-Mn/M(25) exhibited a reduction of 15.3%, while Nb-Mn/M(200) with higher Si/Al ratio decreased only by 3%. Hydrophobic, higher Si/Al catalysts showed better resistance to humidity's negative impact. These findings offered insights into designing efficient catalysts for VOC removal by optimized Si/Al ratio and managing humidity.
研究领域:
环境催化
·
材料科学
·
化学工程
·
等离子体化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2024
·
IF 4.8
Xue-Juan Chen,Xi Hong,Bing Zhan,Xiu-Feng Hou
A series of nanosized “rice ball” like hierarchical beta zeolite aggregates (RBZ x A y , x = 6, 9, 12 or 15; y = 2, 4 or 6) with hierarchical structures are successfully synthesized via gel aging and hydrothermal method without mesoporous template. The as-prepared RBZ x A y zeolites possess two ranges of inter-crystalline mesoporous that formed by zeolite nanoparticles aggregation compared to the non-aged samples (B 12 Z 4 ). The effects of Si/Al ratio and crystallization time on the morphology, structure and surface acidic properties of RBZ x A y were systematically investigated. Meanwhile, RBZ x A y as catalysts were applied in the conversion of lactic acid (LA) to lactide (LT) to investigate their catalytic performance. Benefitting from smaller crystal size, hierarchical structures and higher acid content, the representative catalyst (RBZ 12 A 4 ) exhibited outstanding catalytic activity that the LA conversion was high to 98 % and the LT yield up to 94 %. In addition, RBZ 12 A 4 presented perfect regeneration ability after 10 times recycles. This work provides an effective and facile route to directly synthesis nanocrystals aluminosilicate zeolite with hierarchal structure, and constructs an approach for efficiently converting LA to LT, it has greatly significance for the development of polylactic acid industry.
研究领域:
化学
·
材料科学
·
催化
·
高分子科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）