ChemCatChem
·
2020
·Vol. 12
·期 13
·3512-3522
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IF 4.853
Chunlei Zhang,Guojuan Liu,Ping Wu,Gaofeng Zeng,Yuhan Sun
Graphical Formaldehyde oxidation : Complete HCHO removal was achieved at 90 °C under demanding conditions over the interconnected 3D structure of Na 1.1 Mn 4 O 8 -nanosheet@ Mn 5 O 8 -nanorod biphasic-crystals. Structure defects on the nano-rod/-sheet shared-edges significantly enhance the activity. With the increasing concerns on the formaldehyde (HCHO) hazard, the efficient oxidation of HCHO over affordable and harmless catalyst is of significant practical interest. Herein, the intermediate state of Mn 5 O 8 −Na 1.1 Mn 4 O 8 (Na−Mn 5 O 8 ) biphasic-crystal catalyst, which features Na 1.1 Mn 4 O 8 -nanosheet@ Mn 5 O 8 -nanorod interconnected 3D structure, is successfully fabricated through the anaerobic calcination of manganite followed by alkali treatment. The resultant Na−Mn 5 O 8 exhibits 100 % conversion of HCHO (150 ppm and 60000 h −1 ) and reliable stability (50 h) at 90 °C under demanding water-free feed conditions, which is superior to that of the reference samples of Mn 5 O 8 , Na 1.1 Mn 4 O 8 , MnO 2 and Na−MnO 2 . The experimental results demonstrate that the abundant structure defects (oxygen vacancies) on Na−Mn 5 O 8 , which may locate along the phase interfaces / shared-edges of Mn 5 O 8 nanorods and Na 1.1 Mn 4 O 8 nanosheets, significantly enhance the active oxygen species and finally contribute to the high activity for HCHO oxidation. Furthermore, the 3D structure of Na−Mn 5 O 8 favors mass transfer and fully exposing active sites for the HCHO adsorption and conversion. These findings reveal a way to enhance the catalytic activity of metal oxides via controlling the intermediate state of heteropical crystals.
研究领域:
材料科学
·
环境科学
·
催化化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Aimal Khan,Xianjie Feng,Chuankun Yin,Habib Ullah,Asif Ali Tahir,Bowen Li,Weiming Wang,Xiaoxia Li,Aihua Xu
Less-toxic, cost-effective, stable, and highly efficient catalysts for sodium sulfite (S(IV)) activation are required to degrade organic pollutants from wastewater. Herein, we report the facile thermal synthesis of Mn 2 O 3 @Mn 5 O 8 that activates S(IV) more efficiently than other Mn and transition-metal oxides. Mn 2 O 3 @Mn 5 O 8 exhibits good performance and long-term stability for eliminating various contaminants from aqueous media, including phenol, bisphenol A, nitrobenzene, 2,4-dichlorophenol, and acetaminophen. Its high performance is attributed to its multivalency, unique architecture, surface hydroxyl groups (–OH), and high surface area. X-ray diffractometry and high-resolution transmission electron microscopy revealed that Mn 2 O 3 @Mn 5 O 8 comprises well-combined cubic Mn 2 O 3 and monoclinic Mn 5 O 8 crystalline structures, whereas electron paramagnetic resonance spectroscopy and scavenging tests showed that SO 5 •− , SO 4 •− , and •OH radicals are generated during S(IV) activation, with SO 3 •− as a precursor. The mixed-valence state provides effective and favorable electron transfer via Mn redox cycling (Mn(II) ↔ Mn(III) ↔ Mn(IV)), improving the S(IV) activation performance and catalytic activity. Mn 2 O 3 @Mn 5 O 8 /S(IV) system shows stable performance in the 3.0–7.0 pH range. Density functional theory calculations confirmed the higher catalytic activity as indicated by high –OH adsorption energy and significant inter-charge transformation. This study provides new insights and strategies for the activation of S(IV) using less-toxic metal oxides as catalysts and broadens the scope of heterogeneous Mn-based catalysts and S(IV) chemistry in real-world applications, particularly for the treatment of wastewater.
研究领域:
环境科学
·
材料科学
·
化学
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DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 34
·17902-17914
·
IF 6.895
Lifang Chen,Ting Zhang,Hongye Cheng,Ryan M. Richards,Zhiwen Qi
In order to develop highly active non-precious metal catalysts for the selective oxidation of the platform compound 5-hydroxymethylfurfural (HMF) to the value-added bio-chemical 2,5-diformylfuran (DFF), we prepared high purity bivalent Mn5O8 nanoplates by a microwave-assisted ionic liquid route. The precursor of bivalent Mn5O8 nanoplates was formed through π–π stacking between imidazolium rings of the ionic liquid 1-butyl-3-methyl-imidazolium chloride and extending hydrogen bonds between Cl anions and hydrohausmannite. An oriented aggregation growth occurred on the basis of the Ostwald ripening under microwave heating. The high purity bivalent Mn5O8 nanoplates obtained through calcination at 550 °C for 2 h exhibited high HMF conversion (51%) and DFF selectivity (94%) at 5 bar of oxygen pressure in 2 h. The high concentration of Mn4+ on the exterior surfaces of Mn5O8 nanoplates as active sites coupled with good crystallinity played key roles for desirable mass and heat transfer, and for fast desorption avoiding over-oxidation. The reaction process over the Mn5O8 nanoplates was proposed based on the understanding of Mn4+ active centers and lattice oxygen via a Mn4+/Mn2+ two-electron cycle to enhance their catalytic performance. Furthermore, the Mn5O8 nanoplates could be readily recovered and reused without loss of catalytic activity. Thus, the high purity Mn5O8 nanoplates with good catalytic performance raises the prospect of using the type of sole metal oxide for practical applications.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2026
·
IF 6.6
Jingzhao Lu,Yanfang Zhu,Zhen He,Jun Zhao,Bingxia Duan,Yanyan Lu,Zhiliang Li,Yapeng Zhou,Guizhu Wu
Antibiotic residues pose a serious threat to aquatic environment, underscoring the urgency of developing efficient and stable advanced oxidation technologies. While the activation process based on peroxymonosulfate (PMS) shows great promise, its efficacy is highly dependent on the performance of the catalyst. In this study, a novel Mn 3 O 4 -Mn 5 O 8 nanohybrid was successfully synthesized and its performance in activating PMS for the degradation of tetracycline (TC) was systematically evaluated. By constructing an electron-rich interface, the nanohybrid achieved optimized manganese valence distribution and efficient cycling, leading to significantly enhanced catalytic activity. In the PMS system, the Mn 3 O 4 -Mn 5 O 8 attained 99.4% TC removal within 30 min, with the reaction rate constant (0.150 min⁻ 1 ) significantly exceeding those of the Mn 3 O 4 (0.052 min⁻ 1 ) and Mn 5 O 8 (0.066 min⁻ 1 ) systems, while the manganese leaching rate (3.65%) was much lower than that of unstable Mn 3 O 4 (8.53%). Mechanistic investigations revealed that the outstanding performance originated from interface-driven manganese valence cycling and electron transfer, which synergistically regulated both radical (O 2 ⁻) and non-radical ( 1 O 2 ) pathways. Furthermore, the catalyst exhibited good anti-interference capability in complex water matrices and cycling stability. This work provided a novel design principle centered on interface engineering and valence state synergy for developing high-performance manganese-based catalysts in PMS-driven water purification.
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DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2026
·Vol. 37
·期 2
·e70521
·
IF 3.8
Xu Zheng,Mingzhu Chen,Jun Zhang,Weijun Zhen,Yufeng Guo
The treatment of semi-coking wastewater generated during the semicoke production process has long been a bottleneck restricting the development of the coal chemical industry. The Fenton reaction is recognized as one of the most effective strategies for addressing water pollution; however, the susceptibility to mineralization and poor reusability of highly active catalysts has limited their practical application. Herein, a thermoplastic polyurethane (TPU) doped with oleic acid modified Mn 2 O 3 @Mn 5 O 8 (Mn 2 O 3 @Mn 5 O 8 -OA) composite fiber membrane was prepared via melt-blown spinning and blending using a melt-blown pilot setup. This composite was employed to activate peroxymonosulfate (PMS) for the degradation of semi-coking wastewater, achieving a maximum chemical oxygen demand (COD) removal efficiency of 72.4%. Material characterization confirmed successful catalyst immobilization and enhanced surface properties. Theoretical calculations provided molecular-level insights into the adsorption behavior of phenol and its degradation intermediates. The TPU-based membrane significantly improved catalyst stability and reusability while maintaining high catalytic activity, offering an effective strategy for advanced oxidation processes in complex wastewater treatment.
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）