CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 3.7
Dingding Liu,Yating Huang,Zhenguo Li,Guohua Jing,Yongdan Li,Huawang Zhao
The advancements in engine technology have led to a decrease in exhaust temperatures, hence enhancing the activity of Cu-SSZ-13 at low temperatures becomes crucial and challenging. This enhancement can be achieved using dual-phase metal oxide/Cu-SSZ-13 composite catalysts. In this work, we evaluated the comparative efficacy of Mn 3 O 4 and Mn 2 O 3 and discovered that Mn 3 O 4 exhibited a significantly superior enhancement in deNO x activity of Cu-SSZ-13 at low temperatures, achieving 95% NO x conversion at 200 °C. This is substantially higher than the conversions recorded by Mn 2 O 3 /Cu-SSZ-13 (78%) and Cu-SSZ-13 (40%). Kinetic and IR results demonstrate that Mn 3 O 4 /Cu-SSZ-13 and Mn 2 O 3 /Cu-SSZ-13 composite samples share a same low-temperature pathway, where bridged nitrates formed on the MnO x react with adsorbed on Brønsted acid sites in Cu-SSZ-13. In this reaction pathway, bridged nitrate formation is identified as the rate-determining step. The distinctive structure of Mn 3 O 4 triggers an increase in oxygen vacancies, creating a higher content of chemically adsorbed oxygen, compared to Mn 2 O 3 . Those adsorbed oxygen facilitates bridged nitrate formation. Consequently, due to the larger amount of bridged nitrate formed on Mn 3 O 4 compared to Mn 2 O 3 , the Mn 3 O 4 /Cu-SSZ-13 sample exhibits higher activity.
研究领域:
环境催化
·
材料化学
·
大气污染控制
·
化学工程
·
表面科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ting Huang,Yunyi Ge,Xiao Zhang,Boxiong Shen,Feng Shen
Water poisoning of catalysts presents a significant practical challenge in the removal of pollutants from coal-fired flue gas. Herein, a highly water-resistance Mn catalyst, with a structure of hollow spheres (NS) assembled by nanosheets and modified by inorganic siloxane was developed. The hydrophobic catalyst (Mn-Si 0.06 /NS) showed a 50% increase in VOC removal efficiency compared to Mn/Al 2 O 3 when exposed to wet flue gas containing 10 vol% water vapor. Strikingly, Mn-Si 0.06 /NS exhibited robust SO 2 resistance, especially under flue gas with high water vapor content. Mechanistic results shows that the enhanced water resistance of catalyst resulted from the synergy between morphological structure and the inorganic siloxane modification. DRIFTS and XPS analyses showed that the catalyst effectively prevented the water poisoning effect, which involves lattice oxygen consumption and transformation. The ability of catalyst to utilize oxygen under wet flue gas was also confirmed by product analysis, which revealed a clear preference for the oxidation reaction path of o-xylene compared with Mn/Al 2 O 3 . Molecular dynamics (MD) simulations show the dynamic scenario of VOC and water vapor adsorption on the catalysts and provide an intuitive picture of the catalysts' water resistance.
研究领域:
环境催化
·
材料科学
·
大气污染控制
·
化学工程
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2022
·
IF 6.137
Xueqiang Liu,Diandi Li,Jiguang Li,Jianle Wang,Shujie Liang,Hong Deng
Heavy metal ion pollution (e.g., Hg, Pb, Cr, Cd) that has a great threat to human health is a global concern, because of their great toxicity (e.g., carcinogenicity and mutagenicity). Therefore, it is necessary to find an economical and efficient technology to remove metal. In recent years, modified biochar plays an important role in the removal of heavy metal. However, most of the biochar modification methods rely on high temperature and long time, which limits their application in practical engineering. In this study, we firstly synthesized HMBC (MnO X -OBC, peanut shells as raw materials) using H 2 O 2 -NaOH method, where the materials only need to be modified for 10 min at ambient temperature to obtain high adsorption performance. The maximum Pb(Ⅱ) and Cd(Ⅱ) adsorption capacities of HMBC were 164.59 mg g − 1 and 36.77 mg g − 1 , respectively, which were 7.2 times and 5.6 times that of the unmodified PBC (peanut shells derived biochar ) , and the main adsorption mechanisms were complexation, ion exchange, cation-π interaction and precipitation. The adsorption process of lead and cadmium by HMBC was more consistent with the Freundlich model and Pseudo-second-order adsorption kinetics . HMBC had high selectivity for lead and cadmium, and the adsorption performance of HMBC was basically not reduced after five cycles. The above experimental results show that the newly prepared HMBC has the potential to treat lead and cadmium industrial wastewater.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2014
·
IF 3.309
Yuxi Gao,Xiaodong Wu,Shuang Liu,Duan Weng,Hongwei Zhang,Rui Ran
MnO x –CeO 2 mixed oxides were synthesized using a sol–gel method and the barium-loaded catalyst was prepared by a wet impregnation. Both catalysts were hydrothermally aged at 800 °C for 10 h. The fresh and aged catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), high-resolution transmission electron microscopy (HRTEM), H 2 temperature-programmed reduction (H 2 -TPR), NO temperature-programmed oxidation (NO-TPO) and soot temperature-programmed oxidation (soot-TPO). Compared with MnO x –CeO 2 , the Ba-modified mixed oxides show a much higher hydrothermal stability. Barium exists in the form of orthorhombic carbonate and cubic nitrate on the fresh sample. BaMnO 3 nanoparticles are identified to form at the interface of CeO 2 crystallites upon the hydrothermal ageing. The formation of the perovskites prohibits the sintering of ceria significantly, and consequently maintains the redox property of the aged mixed oxides to a great degree. Additionally, the nanoscaled perovskites themselves also contribute to the catalytic activity of the aged oxides catalyst.
研究领域:
催化材料
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 38
·17984-17998
·
IF 3.3
Si Duan,Guihong Lan,Xiaoting Yang,Yongqiang Liu,Haiyan Qiu,Bo Xu,Yuan Gao,Zhuang Xie
Antibiotic contamination has become one of the most pressing problems in the field of water purification. Using nano-graphite (nano-G) as a carbon carrier, a ZrO2–MnOx/nano-G composite electrode with high catalytic activity was prepared by a hot pressing method based on MnOx/nano-G prepared by a sol–gel method. The results showed that the ZrO2–MnOx/nano-G electrode reduces charge transfer resistance while improving surface oxygen desorption ability. MnOx can catalyze the two-electron reduction of O2 to produce H2O2, which can then be converted to ˙OH and ˙O2−. Thereafter, the results of free radical capture experiments confirmed that ˙O2− played a significant role in the electrocatalytic degradation of tetracycline hydrochloride (TC) by a ZrO2–MnOx/nano-G composite electrode. Furthermore, the abundant hydroxyl groups on the surface of nano-G and ZrO2 particles can be used as active sites for catalyzing the Mn3+/Mn4+ redox reaction, resulting in the generation of additional free radicals. The high-efficiency electrocatalytic degradation of TC was achieved through the synergistic action of the three. Under optimal reaction conditions, the degradation rate of TC reached 93% after 120 min of electrolysis. ZrO2–MnOx/nano-G displayed satisfactory stability following 10 cycles of degradation experiments. Finally, the potential TC degradation pathway was investigated using liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT), and the degradation mechanism was clarified.
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 3
·324
·
IF 4.146
Jinkun Guan,Lusha Zhou,Weiquan Li,Die Hu,Jie Wen,Bichun Huang
SO2poisoning is a great challenge for the practical application of Mn-based catalysts in low-temperature selective catalytic reduction (SCR) reactions of NOxwith NH3. A series of Gadolinium (Gd)-modified MnOx/ZSM-5 catalysts were synthesized via a citric acid–ethanol dispersion method and evaluated by low-temperature NH3-SCR. Among them, the GdMn/Z-0.3 catalyst with the molar ratio of Gd/Mn of 0.3 presented the highest catalytic activity, in which a 100% NO conversion could be obtained in the temperature range of 120–240 °C. Furthermore, GdMn/Z-0.3 exhibited good SO2resistance compared with Mn/Z in the presence of 100 ppm SO2. The results of Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction of H2(H2-TPR) and temperature-programmed desorption of NH3(NH3-TPD) illustrated that such catalytic performance was mainly caused by large surface area, abundant Mn4+and surface chemisorbed oxygen species, strong reducibility and the suitable acidity of the catalyst. The in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) results revealed that the addition of Gd greatly inhibited the reaction between the SO2and MnOxactive sites to form bulk manganese sulfate, thus contributing to high SO2resistance. Moreover, in situ DRIFTS experiments also shed light on the mechanism of low-temperature SCR reactions over Mn/Z and GdMn/Z-0.3, which both followed the Langmuir–Hinshelwood (L–H) and Eley–Rideal (E–R) mechanism.Keywords:SO2poisoning;low temperature;NH3-SCR;in situ DRIFTS
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 3
·1524-1530
·
IF 3.361
Fan Bai,Lincheng Xu,Daode Wang,Li An,Zhanzhong Hao,Fan Li
Manganese oxide composites with mixed valence states were prepared through the hydrothermal method by compositing with Ti4O7 and calcining at different temperatures, and their ORR and OER catalytic performance were investigated. The prepared catalysts were characterized by XRD, SEM-EDS, HRTEM-EDS, and XPS methods to analyse their phase constitution, morphology feature, and surface composition. The major phase of manganese oxides was Mn3O4, which is a one-dimensional structure, and its growth was induced by Ti4O7. The ORR and OER catalytic activity can be enhanced due to the preferred orientation of manganese oxides. Electrochemical measurements, namely CV, LSV and EIS, were utilized for determining the ORR and OER catalytic activity, whereas CA and ADT were used for studying the durability and stability. A Li–O2 battery was assembled to test the electrochemical behavior and properties in practical application. MnOx/Ti4O7 calcined at 300 °C exhibited the best catalytic activity of 0.72 V vs. RHE half-wave potential for ORR and 0.67 V vs. RHE overpotential for OER. The proportion of Mn3+ was also highest in all the MnOx/Ti4O7 composites. The assembled Li–O2 battery shows high performance with a voltage gap of only 0.85 V. Therefore, it can be affirmed that the inducement of Ti4O7 could strengthen the preferred orientation in manganese oxide growth and Mn3+ in MnOx/Ti4O7 plays a vital role in catalyzing ORR and OER, with both improving the ORR and OER bifunctional catalytic performance of manganese oxides.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2026
·
IF 8.2
Youn-Jun Lee,Chohee Yang,Deok Hyun Moon,Eilhann E. Kwon
CO 2 thermochemical treatment yielded MnO x -biochar and CO-rich syngas. • Micro- and mesopore development enhanced BPA adsorption by MnCCB (CO 2 ). • MnO x rich in Mn(IV) and Mn(III) promoted catalytic BPA oxidation. • Char gasification and oxygenate conversion increased yields of CO and H 2 . Adsorptive removal of aqueous organic pollutants is often limited by mass-transfer kinetics to the adsorbent surface. To address this constraint, integrated adsorption-oxidation processes have been widely explored as a strategic measure because they enable in situ degradation of adsorbent-bound organic pollutants, thereby regenerating active sites and prolonging removal performance. However, many such systems require energy inputs and chemical oxidants, which hinder practical implementation. Here, we evaluate MnO x -loaded corncob (CC) biochar produced under a CO 2 atmosphere (MnCCB (CO 2 )) as a bifunctional adsorption-oxidation material for bisphenol A (BPA) removal. Physicochemical characterization showed that CO 2 -assisted fabrication yielded MnO x with a higher oxidation state in MnCCB (CO 2 ) than that in the N 2 -derived analogue (MnCCB (N 2 )). MnCCB (CO 2 ) exhibited increased micro-/mesopore volume and a higher specific surface area. Consistent with these structural advantages, MnCCB (CO 2 ) achieved a BPA removal rate constant of 8.48 × 10 -2 min −1 , outperforming MnCCB (N 2 ) and pristine CC biochars produced under either N 2 or CO 2 . Beyond pollutant removal, Mn-catalyzed CO 2 mediated thermochemical treatment also enhanced syngas formation during MnCCB (CO 2 ) production. This improvement is attributed to selective catalytic reactions between bio-oil and CO 2 , during which CO 2 is converted to CO in the presence of MnO x . Overall, this work demonstrates the potential of CO 2 -assisted thermochemical treatment for the simultaneous production of functional biochar and syngas. Download: Download high-res image (121KB) Download: Download full-size image
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2025
·
IF 4.7
Yinming Fan,Yuanzhen Li,Siqi Jiang,Yanping Zhang,Yinian Zhu,Shengpeng Mo,Lei Liao,Yanan Zhang,Xiaobin Zhou,Zongqiang Zhu
Volatile organic pollutants (VOCs) can serve as an alternative to ammonia for NO reduction, thereby enabling the simultaneous removal of VOCs and NO. In this study, different morphologies of MnO x /CoO x catalysts derived from MOFs were controllably synthesized under various hydrothermal synthesis conditions for the simultaneous removal of 1,2-propanediol and NO. Among the various samples, sample A, characterized by its rod-like structure, demonstrated superior catalytic activity. It achieved simultaneous photothermal coupling for the degradation of 1,2-propanediol and NO under UV irradiation at 240 °C, with conversion rates reaching 52 % and 67 %, respectively. The morphology of the catalysts significantly influences their catalytic performance. The incorporation of Mn increased the structural disorder of the material, thereby reducing the coordination order of Co. This significant change in the coordination environment modulates the intrinsic catalytic activity of the samples, leading to distinct catalytic properties. Furthermore, the catalytic reaction mechanisms were clarified utilizing in-situ DRIFTS combined with calculations based on Density Functional Theory. Sample A, featuring abundant unsaturated cobalt and manganese defects within its distinctive coordination configuration, greatly promoted the conversion of 1,2-propanediol into crucial intermediate species. This study presents a novel approach for the synergistic removal of VOCs and NO x .
研究领域:
催化化学
·
材料科学
·
环境化学
·
纳米材料
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·Vol. 12
·期 3
·112578
·
IF 7.4
Zhao Zheng,Cheng Zhang,Junchen Li,Yan Zhao,Dingli Fang,Ao Han,Peng Tan,Qingyan Fang,Gang Chen
The removal of indoor formaldehyde (HCHO) is crucial for human health. The design of highly catalytically active nonprecious metal catalysts has major challenges, and the use of transition metal element modification to improve the catalytic performance is an effective strategy. In this study, the active component Mn was loaded on highly active crystalline anatase TiO 2 {001}, and the effect of the calcination temperature on the catalytic activity was investigated. The important influence of temperature on the catalyst valence distribution, surface active oxygen species, and content was thoroughly determined by characterization techniques, such as XPS , H 2 -TPR, and O 2 -TPD. The catalytic reaction process was further analyzed by in situ infrared technology to determine the reaction intermediates and to clarify the catalyst reaction poisoning mechanism; additionally, a reasonable HCHO catalytic reaction pathway was proposed with the combination of density function theory calculations. In addition, oxygen defects on the catalyst surface were determined by EPR , and based on theoretical calculations, the oxygen defects could further reduce the reaction energy barrier through the Langmuir-Hinshelwood mechanism. By exposing specific crystal surfaces and increasing the number of oxygen defects, the catalytic activity could be effectively improved; based on these results, our study provides a concept for the subsequent development of nonprecious metal catalysts.
研究领域:
催化化学
·
环境化学
·
材料科学
·
表面科学
·
纳米材料
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Shanliang Jiang,Changhao Li,Yaseen Muhammad,Ying Tang,Ruimeng Wang,Junjie Li,Jing Li,Zhongxing Zhao,Zhenxia Zhao
Construction of highly-active photothermal catalysts featuring merits of high quantum efficiency and superior heat resistance is a great challenge during volatile organic compounds (VOCs) degradation under high humidity. Herein, a facile solvent-induced dimensionality reduction strategy was proposed to engineer a nanosheeted and polycrystalline Cu/Mn-based catalyst (M-Cu/MnO x ) having interfacial oxygen vacancies for enhanced photo-thermal catalytic degradation of toluene under highly humid conditions. Unique Cu-mediated δ-MnO 2 /Mn 3 O 4 nanosheets with high surface area exhibited excellent light absorptivity and photogenerated carrier separation efficiency, as well as superior light-driven thermogenesis. It realized ultra-high (92.8%) toluene conversion and deep mineralization (84.4%) under RH = 80% and continuous catalytic reaction (200 h). Its toluene degradation rate exhibited 3.5–71.9 times higher than reported state-of-the-art photothermal catalysts. The newly designed M-Cu/MnO x catalyst provides a promising, low-cost and alternative for the efficient degradation of toluene and other similar VOCs under humid conditions on large-scale operations.
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2016
·Vol. 45
·期 26
·10530-10538
·
IF 4.177
Hui Hua Peng,Jie Chen,De Yi Jiang,Xiao Long Guo,Hao Chen,Yu Xin Zhang
MnOx-decorated MgAl layered double oxide (M-LDO) was fabricated via merging of memory effect and anion intercalation, accompanied by the reduction/calcination process. The as-obtained nanocomposites were characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD) and N2 adsorption–desorption. To clarify the detailed formation mechanism, optimized calcination temperature/time and temperature for methyl orange (MO) adsorption were investigated. Adsorption experiments showed that the adsorption behaviour fitted well with a Langmuir isotherm and pseudo-second-order model, and the maximum adsorption capacity calculated from the Langmuir model was 555.55 mg g−1. The adsorption process was exothermic and spontaneous in nature. Moreover, the used adsorbent could be regenerated for at least five cycles (94% removal retained) through a thermal procedure, indicating that the M-LDO hybrid is a promising adsorbent with promising ability to remove anionic dye pollutants from wastewater.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）