CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yang Zong,Yufei Shao,Wenjie Ji,Yunqiao Zeng,Jun Xu,Wen Liu,Longqian Xu,Deli Wu
Traditional advanced oxidation processes (AOPs) generally suffer from the inevitable deactivation of catalysts and the ineffective consumption of transient reactive species (TRSs) that compromise the efficiency in destructing aqueous contaminants. Herein, it was interestingly found that trace Mn(II) could robustly catalyze the oxidation of organic contaminants by periodate (PI), with the performance was much better than the representative TRSs-dominated AOPs (i.e., the Fe(II)-activated hydrogen peroxide, peroxymonosulfate (PMS), peroxydisulfate and PI processes). Multiple lines of evidence excluded the oxidative contributions of TRSs, instead the stoichiometric formation of colloidal MnO 2 via the condensation of di-μ-oxo-bridged Mn(IV) cluster was confirmed by UV-vis, X-ray absorption near edge structure spectroscopy and density functional theory calculation. Dependent on the structure of substrate, MnO 2 colloids solely or simultaneously served as oxidant and catalyst for the enhanced treatment performance. Benefiting from the non-TRSs-involved oxidation strategy and the catalytic effects of Mn species, the trace-Mn(II)/PI process even outperformed the Co(II)-activated PMS counterpart (i.e., one of the most efficient AOPs known at present) on oxidant utilization efficiency. This study not only elucidated the roles of Mn(II) and colloidal MnO 2 in PI-mediated contaminant degradation, but also signified the superiority of trace catalyst-assisted process without TRSs involvement in avoiding undesired side reactions and maximizing oxidation efficiency.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xing Yuan,Lingquan Meng,Chaohe Zheng,Haibo Zhao
Perovskites have been recognized as affordable substitutes for noble-metal catalysts for their tunable catalytic activity and thermal stability. Nevertheless, the highly demanding synthesis procedure still hinders the application of perovskites in catalytic combustion. In this work, a series of nanostructured SiTiO3 perovskites with B-site partial substitution by Co, Fe, Mn, Ni, and Cu are synthesized via flame spray pyrolysis in one step. The comprehensive characterizations on textural properties of nanostructured perovskites reveal that the flame-made perovskite nanoparticles all exhibit high crystal purity and large specific surface area (∼40 m2/g). Furthermore, the highest catalytic activity is achieved by SrTi0.5Co0.5O3 due to the formation of favorable oxygen vacancies, outstanding reducibility, and oxygen desorption capability. Additionally, the presence of 10 vol % water vapor during long-term testing indicates remarkable durability and water resistance. Finally, the CO oxidation and CH4 dehydrogenation on SrTiO3 incorporating Co atoms are more thermodynamically and kinetically favorable than those on other doped surfaces.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Wen Qin,Jianshan Peng,Jingru Yang,Yang Song,Jun Ma
In this study, the relative residual UV absorbance (UV 254 ) and/or electron donating capacity (EDC) was investigated as a surrogate parameter to evaluate the abatement of micropollutants during the Fe(II)/PMS and Mn(II)/NTA/PMS processes. In the Fe(II)/PMS process, due to the generation of SO 4 •- and •OH at acidic pH, UV 254 and EDC abatement was greater at pH 5. In the Mn(II)/NTA/PMS process, UV 254 abatement was greater at pH 7 and 9, while EDC abatement was greater at pH 5 and 7. This was attributed to the fact that MnO 2 was formed at alkaline pH to remove UV 254 by coagulation, and manganese intermediates (Mn(V)) were formed at acidic pH to remove EDC via electron transfer . Due to the strong oxidation capacity of SO 4 •- , •OH and Mn(V), the abatement of micropollutants increased with increasing dosages of oxidant in different waters in both processes. In the Fe(II)/PMS and Mn(II)/NTA/PMS processes, except for nitrobenzene (∼23% and 40%, respectively), the removal of other micropollutants was greater than 70% when the oxidant dosages were greater in different waters. The linear relationship between the relative residual UV 254 , EDC and the removal of micropollutants was established in different waters, showing a one-phase or two-phase linear relationship. The differences of the slopes for one-phase linear correlation in the Fe(II)/PMS process (micropollutant-UV 254 : 0.36–2.89, micropollutant-EDC: 0.26–1.75) were less than that in the Mn(II)/NTA/PMS process (micropollutant-UV 254 : 0.40–13.16, micropollutant-EDC: 0.51–8.39). Overall, these results suggest that the relative residual UV 254 and EDC could truly reflect the removal of micropollutants during the Fe(II)/PMS and Mn(II)/NTA/PMS processes.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Qingfeng Zhou,Junzheng Wang,Rurong Zheng,Yun Gong,Jianhua Lin
Two chromite spinel-based composite materials, Mn II Cr III 2 O 4 /Mn II Mn III 2 O 4 /C and CoCr 2 O 4 /C are successfully synthesized by a solid-state conversion process via annealing Mn Cr-coordination compound and Co Cr-coordination compound at 350 °C in air for 1 h, respectively. The two composite materials both show the morphology of nanoparticles , in which the spinels are embedded in carbon matrix into a continuous phase. The as-prepared composite materials are used as supercapacitor electrodes in basic electrolyte. The Mn II Cr III 2 O 4 /Mn II Mn III 2 O 4 /C composite material possesses a high specific capacity of 184.0 mAh g −1 at a current density of 0.5 A g −1 with a superior rate capability of 138.3 mAh g −1 (75.2% retention) at 20 A g −1 . Meanwhile, CoCr 2 O 4 /C nanoparticles also deliver a high specific capacity of 158.8 mAh g −1 at a current density of 0.5 A g −1 with a superior rate capability of 125.0 mAh g −1 (78.7% retention) at 20 A g −1 . The good supercapacitive behaviors of the two composite materials are probably attributed to the characteristics of bimetallic compound and the presence of multiple valence states in the samples, giving rise to obvious redox responses. And the Mn II Cr III 2 O 4 /Mn II Mn III 2 O 4 /C and CoCr 2 O 4 /C composites possess reversible electrochromism .
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Zhicheng Xu,Jin Xiong,Yuran Li,Junxiang Guo,Bin Wang,Tingyu Zhu
For industrial flue gas purification at medium and low temperatures, it is highly necessary to promote the denitrification activity of V-based catalysts in a SO2 atmosphere. Transition metals (Ce, Co, Fe, and Mn) are used to modify V/Ti catalysts to improve SO2 resistance with ammonium bisulfate deposition on the catalysts. Sulfation on Ce with less ammonium bisulfate deposition considerably improves the SO2 resistance of V1Ce5/Ti, and stable sulfation on TiO2 promoted by Co provides additional Brønsted acid sites for V1Co5/Ti to reduce the deactivation. Serious sulfation on V1Mn5/Ti with large ammonium bisulfate deposition on V1Fe5/Ti causes deeper deactivation. The formation mechanism of ammonium bisulfate on active metal sites and TiO2 carriers has been clarified. SO2 is adsorbed on V sites and transition metal sites followed by oxidation and ammoniation or adsorbed on TiO2 carriers followed by ammoniation and oxidation. The first pathway is more dominant than the second pathway in the presence of O2 with the co-oxidation of SO2 by O2 and lattice oxygen. The initial formation temperature and stable temperature of dominant intermediates were determined by in situ DRIFTS. SO2 adsorbed on TiO2 carriers is oxidized by V sites above 170 °C to form a tridentate sulfate, while SO2 adsorbed on transition metal sites is initially oxidized by transition metal sites above 50 °C to form monodentate and bidentate sulfates, as well as competitively oxidized by V sites above 170 °C to form tridentate sulfates. The selective adsorption of SO2 on transition metal sites or TiO2 carriers and the competitive oxidation of SO2 by transition metal sites and V sites provide a synergistic effect between V sites and transition metal sites to reduce ammonium sulfate deposition and release more active sites. These findings provide theoretical guidance to design and prepare V-based catalysts with high denitrification activity in the presence of SO2.
✓ 已验证
产品关联
DOI
高影响因子
Toxics
·
2024
·Vol. 12
·期 7
·524
·
IF 3.9
Yuanzhen Li,Yinming Fan,Yanhong Wang,Yinian Zhu,Zongqiang Zhu,Shengpeng Mo,Xiaobin Zhou,Yanping Zhang
VOCs can be used instead of ammonia as a reducing agent to remove NO, achieving the effect of removing VOCs and NO simultaneously. Due to the high energy consumption and low photocatalytic efficiency required for conventional thermocatalytic purification, photothermal coupled catalytic purification can integrate the advantages of photocatalysis and thermocatalysis in order to achieve the effect of pollutants being treated efficiently with a low energy consumption. In this study, samples loaded with Co and Mn catalysts were prepared using the hydrothermal method on Fe-MOF with various morphologies. The catalytic performance of each catalyst was analyzed by studying the effects of their physicochemical properties through various characterizations, including XRD, SEM, BET, XPS, H2-TPR, TEM and O2-TPD. The characterization results demonstrated that the specific surface area, pore volume, high valence Co and Mn atoms, surface adsorbed oxygen and the abundance of oxygen lattice defects in the catalysts were the most critical factors affecting the performance of the catalysts. Based on the results of the performance tests, the catalysts prepared with an octahedral-shaped Fe-MOF loaded with Co and Mn showed a better performance than those loaded with Co and Mn on a rod-shaped Fe-MOF. The conversions of acetone and NO reached 50% and 64%, respectively, at 240 °C. The results showed that the catalysts were capable of removing acetone and NO at the same time. Compared with the pure Fe-MOF without Co and Mn, the loaded catalysts showed a significantly higher ability to remove acetone and NO simultaneously under the combination of various factors. The key reaction steps for the catalytic conversion of acetone and NO on the catalyst surface were investigated according to the Mars–van Krevelen (MvK) mechanism, and a possible mechanism was proposed. This study presents a new idea for the simultaneous removal of acetone and NOxby photothermal coupling.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Chuanyan Wu,Guole Zhang,Haiqian Zhao,Mingqi He,Hongguang Li,Zhuangzhuang Zhang,Jiaxin Ying,Wei Zhou
It is a promising technology to degrade benzene by using the strong oxidizing ·OH produced by H 2 O 2 decomposition. However, in practical engineering, the low yield and utilization rate of ·OH affect the degradation effect, and the development of new catalysts is the key to solve this problem. The effects of Mn-doped on the decomposition of H 2 O 2 on the surface of Cu (Mn-Cu) to obtain ·OH were studied by combining density functional theory, including the adsorption and decomposition characteristics of H 2 O 2 and the ineffective consumption reaction of ·OH on the surface. At the same time, the specific reaction process between benzene and · OH on the surface was studied, and the effectiveness improvement of various reactions on the surface of Mn-Cu was analyzed in detail. It is found that the charge transfer between Mn and Cu forms positive and negative charge centers on the surface, the O-O bond break of H 2 O 2 molecules that promote adsorption on the surface occurs homolysis, and has a significant inhibitory effect on the ineffective consumption reaction between ·OH and H 2 O 2 molecules and ·HO 2 , thus improving the yield and utilization of ·OH. At the same time, the reaction energy barrier between ·OH and benzene was significantly reduced, the energy barrier of the first stage of degradation was reduced from 206.86 kJ/mol to 27.02 kJ/mol, and the degradation efficiency of benzene was greatly improved. And the effect improvement was verified through degradation experiments. The degradation rate of Mn-Cu surface is higher than that of Cu surface at all stages, and the final degradation rate can reach about 89%. By clarifying the above reaction mechanism, it provides theoretical support for the development of new catalysts.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Xinghao Wang,Wenrui Xiang,Siyuan Wang,Jiali Ge,Ruijuan Qu,Zunyao Wang
Soluble manganese(III), stabilized by ligands as Mn(III)-L complexes, are ubiquitous in natural waters and wastewaters and can potentially serve as both the oxidant and reductant in one-electron transfer reactions with organic contaminants. In this study, the oxidative transformations of 14 phenolic endocrine disrupting chemicals (EDCs) by in situ-formed Mn(III)-L complexes, generated from irradiated water containing Mn(II) and humic acid, were investigated. The pseudo-first-order rate constants (kobs, h–1) of these phenols varied from 1.0 × 10–4 to 5.9 × 10–2. A quantitative structure–activity relationship model was developed, which suggests that the electron-donating ability (EHOMO) of phenolic chemicals was the most important molecular characteristic for the Mn(III)-L-mediated oxidative transformation. Phenol transformation was initiated by the generation of a phenoxyl radical through electron transfer to Mn(III)-L. Subsequent self-coupling reactions between phenoxyl radicals resulted in the formation of self-coupling dimers and trimers. With the addition of simple phenol as a cosubstrate, enhanced transformations of these phenolic EDCs were clearly observed, and cross-coupling products of simple phenol and the substrates were also detected. In addition, a reaction activation energy calculation based on the transition-state theory indicated that the cross-coupling reaction was more likely than the self-coupling reaction to occur in the presence of phenol. This work provides new insights into the environmental fate of phenolic compounds.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Xinghao Wang,Siyuan Wang,Ruijuan Qu,Jiali Ge,Zunyao Wang,Cheng Gu
Reaction with soluble Mn(II) has been considered as a main decay pathway for superoxide in natural waters, accompanied by an important Mn redox cycling. In this study, the interaction of Mn(II) and humic acid (HA) was investigated in visible light irradiated water. Our results indicate that HA may play a dual role to act as a photosensitizer to produce superoxide anions (O2–) and as a strong ligand to stabilize the Mn(III), forming soluble Mn(III)L species for substrate transformation. Furthermore, the reaction kinetics, products, and mechanisms of chlorophene (CP) and estradiol (E2) mixture in the Mn(II)/HA/visible light reaction systems were assessed. The removal of CP and E2 was enhanced by 24.3% and 13.2%, respectively, in mixture solution at initial concentration of 1.0 μM for each target contaminant, as compared to the case of single-compound degradation. Product identification and density functional theory calculations indicated that cross-coupling reaction of CP and E2 radicals was more likely to occur than the self-coupling reaction in mixture solution. In addition, estrogenic activities of initial reaction solution were also effectively decreased during the transformation process. These findings provide new insights into Mn(III)-mediated reactions to better understand the environmental fate of organic contaminant mixture in waters.
✓ 已验证
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 10
·6111-6120
·
IF 6.895
Dongxu Zhu,Haihang Ye,Zheming Liu,Jun Liu,Hao Fu,Yanbin Huang,Feng Teng,Zhijie Wang,Aiwei Tang
Multinary copper-based chalcogenide nanocrystals (NCs) as light-driven photocatalysts have attracted extensive research interest due to their great potential for generating sustainable energy without causing environmental concerns. However, systematic studies on the growth mechanism and related photocatalytic activities involving different valent metal ions (either M2+ or N3+) as foreign cations and monoclinic Cu1.94S NCs as the ‘parent lattice’ have rarely been carried out. In this work, we report an effective seed-mediated method for the synthesis of heterostructured Cu1.94S–MS NCs (M = Zn, Cd and Mn) and alloyed CuNS2 NCs (N = In and Ga). A typical cation exchange process took place prior to the growth of heterostructured NCs, while further inter-cation diffusion occurred only for the alloyed NCs. When compared with Cu1.94S NCs, all the heterostructured Cu1.94S–MS NCs and CuGaS2 NCs showed enhanced photocatalytic activities toward hydrogen production by water splitting, owing to their tailored optical band gaps and energy level alignments. Although optically favored, CuInS2 ANCs were not comparable to others due to their low conduction band minimum for the reduction of H2O to H2.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 23
·10020-10032
·
IF 9.8
Qiyuan Zheng,Li Zeng,Zuoying Cao,Shengxi Wu,Qinggang Li,Mingyu Wang,Wenjuan Guan,Guiqing Zhang
As the production of electric vehicles and lithium-ion batteries continues to rise, concerns over resource scarcity and supply shortages of critical metals, including Cu, Ni, Co, Mn, and Li, have become increasingly urgent. To address these concerns and promote environmental protection, there is a growing demand for the recycling of hazardous waste containing these critical metals as secondary resources. Therefore, this paper proposes a novel synergistic solvent extraction system of D2EHPA-NNPA, which fills a gap in the lack of a suitable extraction system for the hydrometallurgical industry of secondary resources containing Cu, Ni, Co, Mn, and Li. With the specific extraction sequence of D2EHPA-NNPA, a novel process has been designed and proposed for the stepwise extraction of Cu, Ni, Co, Mn, and Li from secondary resources, which significantly simplifies process flows while avoiding cross-contamination of the extractants and the production of industrial wastewater. Furthermore, the proposed “extraction-scrubbing-stripping” process has been investigated from both macroscopic and microscopic perspectives, demonstrating that the novel synergistic solvent extraction system of D2EHPA-NNPA is a viable option for industrial applications to promote a circular economy and achieve sustainability objectives.
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2011
·
IF 5.874
Huan Yan,He-Fang Wang
Room-temperature phosphorescence (RTP) turn-on assay of heparin with tunable sensitivity and detection window was demonstrated on the basis of the target induced self-assembly of polyethyleneimine capped Mn-doped ZnS (PEI-Mn-ZnS) QDs. The proposed method can cover the whole therapeutic dosing concentration range in postoperation and long-term therapy (0.2–1.2 U/mL, 1.7–10 μM) and cardiovascular surgery (2–8 U/mL, 17–67 μM) in 10 mM Tris–HCl (pH 7.4) buffer and can be applied for heparin determination in 100-fold diluted human serum samples. The tunable sensitivity and detection window was ascribed to the tunable particle size and ligand loading amount of PEI-Mn-ZnS QD arising from the chain length (or molecule weight) and feed amount of PEI. The chain length of PEI exhibited significant effect on the particle size and ligand loading amount and ultimately had important influence on both the sensitivity and detection window. The feeding amount of PEI, however, greatly affected the ligand loading amount alone and, in turn, affected only the detection window.
✓ 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）