CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jiaqi Si,Jiayong Ni,Tian Lan,Guofeng Zhao,Ye Liu,Yong Lu
The Mn-NaW/TiO 2 catalyst shows a broad promise for practical application in the fluidized-bed oxidative coupling of methane (FB-OCM) but there is still a lack of understanding of the role of TiO 2 . Herein, a series of Mn-NaW/TiO 2 catalysts with tuned anatase and rutile compositions were obtained by varying the calcination temperature and duration and were examined in the FB-OCM reaction. It was found that the Mn-NaW/TiO 2 catalysts with a proper rutile fraction (F R ) of 30–90% could fully initiate the FB-OCM reaction at 760 °C, achieving 26–29% CH 4 conversion and 65–73% C 2 -C 3 selectivity for a feed gas of CH 4 /O 2 (5/1, vol/vol; no dilution gas) at 760–840 °C. The lattice oxygen in the TiO 2 did not directly participate in the FB-OCM reaction, whereas the TiO 2 phase played a crucial role in tuning the lattice oxygen activity of Mn 2 O 3 through the redox cycle of “2Mn 2 O 3 + 4TiO 2 ↔ 4MnTiO 3 + O 2 ”. The higher the rutile phase content in the Mn-NaW/TiO 2 catalysts, the lower the activity of the lattice oxygen in Mn 2 O 3 but conversely the higher the selectivity to C 2 -C 3 selectivity. In addition, the density functional theory (DFT) calculations confirmed that the anatase-rutile junction was conductive to the thermal reduction of Mn 2 O 3 to form MnTiO 3 .
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·
IF 3.1
Xiaofei Hao,Ran Wang,Xiumin Tan,Xiufeng Zhang,Xupo Liu,Zhaoyang Wu,Dongli Yuan
Fabricating efficient oxygen evolution reaction (OER) electrocatalysts is crucial for water electrocatalysis. Herein, the spinel-type high-entropy oxides of (Co, Fe, Mn, Ni, Cr) 3 O 4 were synthesized through the high-temperature calcination approach. The influences of calcination temperatures on structures and electrochemical properties were investigated. The optimized catalyst of HEO-900 contains the hybrid structure of regular polyhedrons and irregular nanoparticles, which is beneficial for the exposure of electrochemically active sites. It was identified that the abundant high-valence metal species of Ni 3+ , Co 3+ , Fe 3+ , Mn 4+ , and Cr 3+ are formed during the OER process, which is generally regarded as the electrochemically active sites for OER. Because of the synergistic effect of multi-metal active sites, the optimized HEO-900 catalyst indicates excellent OER activity, which needs the overpotential of 366 mV to reach the current density of 10 mA cm −2 . Moreover, HEO-900 reveals the prominent durability of running for 24 h at the current density of 10 mA cm −2 without clear delay. Therefore, this work supplies a promising route for preparing high-performance multi-metal OER electrocatalysts for water electrocatalysis application.
✓ 已验证
DOI
PubMed
高影响因子
ChemCatChem
·
2025
·
IF 3.9
Qian Li,Jie Zhang,Tong Yu,Jinwei Chen,Gang Wang,Zongbo Shi,Runsheng Zhuo,Ruilin Wang
Propane dehydrogenation (PDH) is a pivotal technology for propylene production. Supported Pt catalysts for PDH are often subjected to nanoparticle agglomeration and coke deposition, thus limiting their stability and efficiency. Herein, we constructed a high-performance Pt-Ce catalyst consisting of CeO x with redox properties and active Pt species with the regulated electronic properties. Through the controllable impregnation, the unique structure of adjacent Pt-CeO x sites were elaborately supported on the Mn-modified Silicalite-1 (Mn-S-1). Characterization results reveal that the generated Ce 3+ /V O species contribute to the formation of electron-deficient Pt 0 -V O -Ce 3+ active sites via hydrogen spillover and electron transfer. Benefiting from the high dispersion of active components, appropriate acidity, redox activity of V O , and electron-deficient Pt 0 sites, the optimal 0.5Pt0.2Ce/Mn-S-1 catalyst exhibits superior propane conversion of 38.23%, propylene selectivity of 88.45%, and excellent coke resistance. This study not only reveals the intrinsic correlation between active Pt and CeO x species but also provides valuable guidance for designing highly efficient catalysts. Graphical A high-performance Pt-Ce catalyst consisting of CeO x with redox properties and active Pt species with the regulated electronic properties was constructed through a controllable impregnation. Benefiting from the high dispersion of active components, appropriate acidity, redox activity of V O , and electron-deficient Pt 0 sites, the optimal 0.5Pt0.2Ce/Mn-S-1 catalyst exhibits superior propane dehydrogenation performance.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yan Sun,Ranxin Li,Qiubo Wang,Wen-da Oh,Mingjie Huang,Xiaohui Wu,Tao Zhou
The concept of converting biowaste to energy is popular worldwide; however, overcoming the trade-off between bio-oil recovery and obtaining functional biochar remains challenging. This study investigated the effects of three transition metal ions (Mn 2+ , Cu 2+ and Fe 2+ ) throughout the entire process of recovering 5-hydroxymethylfurfural (5-HMF) from forestry waste and on the catalytic abilities of biochar derived from the oil-extracted residue. The Cu 2+ , Fe 2+ , and Mn 2+ ions significantly increased 5-HMF yields by 93- to 158-fold compared to the metal-free control. However, only marginal improvements in the catalytic ability of the residue-derived biochar for persulfate activation were observed for Cu- or Fe-doped biochar, despite the general benefit of transition metal doping for biochar functionalization. Interestingly, a dual Mn-mediated promotion was achieved beyond enhancing 5-HMF production. The Mn-doped biochar (Mn-Biochar) exhibited excellent peroxydisulfate (PDS) activation capability, enhancing the degradation of the antibiotic sulfamethoxazole (SMX) by 6.6- to 15.0-fold. Characterizations revealed that incorporated nitrogen was responsible for this enhancement. N-doping transformed the Mn species into MnO, which tripled the Mn loading capacity and enhanced the electrical conductivity of the biochar. The formed Mn-N x structure in the biochar (Mn-N-FBBC) facilitated polarization of the O O bond and cleavage of the S O bond in PDS, generating 1 O 2 for SMX degradation. Life cycle assessment (LCA) indicated that this dual Mn-mediated process for 5-HMF recovery and biochar production offers synergistic benefits, realizing the “waste-resource-material-treatment” paradigm in biomass conversion.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Guangzhi He,Meng Gao,Yue Peng,Yunbo Yu,Wenpo Shan,Hong He
Mn-based oxides exhibit outstanding low-temperature activity for the selective catalytic reduction of NOx with NH3 (NH3-SCR) compared with other catalysts. However, the underlying principle responsible for the excellent low-temperature activity is not yet clear. Here, the atomic-level mechanism and activity-limiting factor in the NH3-SCR process over Mn-, Fe-, and Ce-based oxide catalysts are elucidated by a combination of first-principles calculations and experimental measurements. We found that the superior oxidative dehydrogenation performance toward NH3 of Mn-based catalysts reduces the energy barriers for the activation of NH3 and the formation of the key intermediate NH2NO, which is the rate-determining step in NH3-SCR over these oxide catalysts. The findings of this study advance the understanding of the working principle of Mn-based SCR catalysts and provide a fundamental basis for the development of future generation SCR catalysts with excellent low-temperature activity.
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Minjing Chen,Wenyang Wang,Zhepu Shi,Zhaoping Liu,Cai Shen
Solid electrolyte interphase (SEI) grown on electrode surfaces during charge-discharge processes plays a key role in the cycle performance of lithium-ion batteries. In-situ study of cathode electrolyte interphase (CEI) is challenging due to the complicated interfacial reactions on the cathode materials including gas formation and the formation of thin CEI film. Herein, we applied the electrochemical atomic force microscope (EC-AFM) to study the interfacial changes in high energy density Li- and Mn-rich (LMR) materials with an F-rich electrolyte (1 M LiPF 6 FEC/FEMC/HFE). The study indicated that the electrolyte formed a uniform and dense passivation CEI film on the LMR material surface at high voltage. The CEI is composed of inorganic LiF substrate as confirmed by X-ray photoelectron spectroscopy (XPS). The assembled battery (LMR||Li) shows an excellent cycle performance and maintains capacity at 85.5% after 100 cycles, compared to the 13.7% retention rate of commercial carbonate electrolyte (1 M LiPF 6 EC/EMC/DMC).
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Xinghao Wang,Jiayi Yao,Siyuan Wang,Xiaoxue Pan,Ruiyang Xiao,Qingguo Huang,Zunyao Wang,Ruijuan Qu
Photodegradation of pollutants is classically explained by reaction with reactive oxygen species. However Mn(III) may also remove pollutants, but direct evidence is actually lacking. Here we investigated the role of soluble Mn(III) on phototransformation of four typical estrogens, namely estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2), in the presence of Mn(II) and humic acid . Conversion rates of 60.2%, 89.0%, 87.6%, and 80.2% were achieved for E1, E2, E3, and EE2, respectively, after 72 h visible light irradiation. A detailed quenching experiments revealed that soluble Mn(III), and not reactive oxygen species, was the oxidant responsible for estrogen removal. The determination of Mn(III) concentration provided direct proof of the role of Mn(III)-based oxidizers in the conversion of estrogens. Soluble Mn(III) can form complexes with humic acid, and about 6.51 μM of Mn(III)-humic acid was formed from 20 μM of Mn(II) in the presence of 5 mg/L of humic acid. Furthermore, product identification and theoretical computation demonstrated that estrogens are mainly converted into oligomers (dimers, trimers, tetramers, etc.) via a single-electron process. According to these results, the oxidation of Mn(II) to Mn(III) is initiated by superoxide ion (O 2 •- ) generated from dissolved oxygen in the presence of humic acid under visible light irradiation. The formed soluble Mn(III) strips the estrogens of a single electron to generate phenoxyl radicals, which undergo oligomerization, while leads to regeneration of Mn(II). Hence, the photochemical Mn(II)-Mn(III) redox cycling may significantly influence the fate and transformation of estrogens in waters.
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 51
·32146-32154
·
IF 3.108
Chengkai Pang,Yuqun Zhuo,Qiyu Weng
A series of Mn-exchanged SAPO-34 catalysts were synthesized and developed as catalysts for the low temperature selective catalytic reduction (SCR) of NO with ammonia in the presence of excess oxygen. 4Mn/SAPO-34 showed the highest SCR activity in the temperature range of 120–210 °C. The microstructure of zeolite supports, acidity, manganese species and reaction mechanism were investigated in detail by BET, NH3-TPD, UV-Vis, H2-TPR, XPS and in situ DRIFTS. Mn3+ and Mn4+ related species were proved to be the active sites for the SCR reaction. The Eley–Rideal mechanism was proved to be effective on 4Mn/SAPO-34 for the low temperature SCR reaction in which coordinated NH4+ species react with gas-phase NO to form an activated transition state and subsequently decomposed to N2 and H2O.
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Ping Zhang,Guohua Zhang,Yukun Liu,Yuxin Fan,Xinyue Shi,Yiming Dai,Shiwen Gong,Jingrong Hou,Jiwei Ma,Yunhui Huang,Renyuan Zhang
Fe/Mn-based layered oxide cathode is regarded as a competitive candidate for sodium-ion batteries (SIBs) because of its high theoretical capacity, earth abundance and low cost. However, its poor cycling stability still remains a major bottleneck. Herein, P 2/O3 biphasic Na 0.67 Fe 0.425 Mn 0.425 Cu 0.15 O 2 layered oxide is successfully synthesized via a sol–gel method. It is observed that Cu substitution can facilitate the conversion of P 2 to O3 phase, and the P 2/O3 composite structure can be obtained with an appropriate amount of Cu. Meanwhile, in-situ XRD reveals that constructing P 2/O3 composite structure can realize the highly reversible phase transition process of P 2/O3– P 2/ P 3–OP4/OP2 and decrease the lattice mismatch during Na + insertion/extraction. Consequently, the biphasic P 2/O3-Na 0.67 Fe 0.425 Mn 0.425 Cu 0.15 O 2 electrode exhibits 87.1 % capacity retention after 100 cycles at 1C, while the single phase P 2-Na 0.67 Fe 0.5 Mn 0.5 O 2 electrode has only 36.4 %. Therefore, the constructing biphasic structure is proved to be an effective strategy for designing high-performance Fe/Mn-based layered oxide cathodes.
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Biao Li,Zhi-Ying Yan,Xiao-Na Liu,Chen Tang,Jun Zhou,Xia-Yuan Wu,Ping Wei,Hong-Hua Jia,Xiao-Yu Yong
Phenolic compounds are problematic byproducts generated from lignocellulose pretreatment . In this study, the feasibility degradation of syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) by Bio-Electro-Fenton (BEF) system with a novel Fe–Mn/graphite felt (Fe–Mn/GF) composite cathode were investigated. The nano-scale Fe–Mn multivalent composite catalyst with core shell structure distributed more evenly on GF surface to form a catalyst layer with higher oxygen reduction reaction performance. Accordingly, the maximum power density generated with Fe–Mn/GF cathode was 48.1% and 238.9% higher than Fe/GF and GF respectively, which further enhanced the in situ generation of H 2 O 2 due to the superiority of nano-scale core shell structure and synergistic effect of Fe and Mn species. The degradation efficiency of the three phenolic compounds in the BEF system could reached 100% after optimization of influencing parameters. Furthermore, a possible SA degradation pathway by BEF process in the present system was proposed based on the detected intermediates. These results demonstrated an efficient approach for the degradation of phenolic compounds derived from lignocellulose hydrolysates.
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Lu Long,Kaiji Xu,Kok Bing Tan,Dongren Cai,Yucheng Yang,Shu-Feng Zhou,Guowu Zhan
Catalytically agitating paddles are essential to perform liquid-solid heterogeneous catalytic reactions on an industrial scale due to the improved mass transfer and easy catalyst recovery. Herein, bimetallic oxides were formed after the calcination of nanomaterials derived from metal-organic frameworks (MOFs). Particularly, Mn(M)-BTC nanomaterials were synthesized by self-assembly of Mn 2+ ions (mixed with various dopants such as Cu 2+ , Ce 3+ , or Fe 2+ ) and H 3 BTC ligands in a mixed solvent of ethanol and water. It was found that in the powdery form, the Mn-Cu oxide derivate exhibited the highest degradation rate in the catalytic wet peroxide oxidation process (CWPO process), which was significantly higher than that of single metal oxide as well as Mn-Fe and Mn-Ce oxide derivates. The reason was caused by the synergistic effect between Mn-Cu promoted the formation of Mn 3+ and Cu + species to boost the CWPO reaction. Furthermore, the obtained Mn-Cu powdery catalysts were 3D-printed to obtain monolithic agitating paddles with different geometries, which were then mounted on a central shaft in the stirred reactor. An advanced oxidation process was used to investigate the effect of 3D patterns on the degradation efficiency of various organic dyes. It was discovered that the 3D-printed grid with higher cell density (484 cpsi) had better liquid mixing efficiency and thus better catalytic performance, which could be repeatedly used more than seven times. Additionally, the numerical simulation analysis (computational fluid dynamics) revealed a good mixing efficiency and improved mass transfer in the entire reactor equipped with the designed monolithic agitating impellers.
✓ 已验证
DOI
高影响因子
Talanta Open
·
2022
·
IF 0
Jinping Yue,Qing Lv,Wan Wang,Qing Zhang
In this work, a new paper-based device (PAD) was developed for the colorimetric detection of multiple heavy metals. The sensing principle of this PAD is based on the analyte-regulated photocatalytic activity of quantum dots (QDs) to certain substrates. The PAD consisted of three filter paper layers, defining a sample area, three channels, and three testing areas. Three photocatalytic reactions between different QDs and their corresponding substrates could be performed in one device, achieving the simultaneous detection of Cu(II), Mn(II), and Hg(II). The detection limits are 7.3 nM for Cu(II), 5.4 nM for Mn(II), and 8.1 nM for Hg(II), respectively. This PAD was applied to analyze real samples and the results were consistent with those obtained by inductively coupled plasma-optical emission spectrometer. This approach may provide a promising colorimetric sensing platform for multi-target analysis.
✓ 已验证
DOI
危险品化学品经营许可证（带存储）