ENERGY & FUELS
·
2020
·
IF 3.421
Jun Chen,Yi Chen,Dzmitry Hrynsphan,Yu Mei,Hua Pan,Jiali Wu,Jianmeng Chen,Jiachao Yao
FeII(EDTA) solution has been considered an efficient option in wet flue gas denitrification, whereas the generated FeII(EDTA)–NO restricts its wide application, suggesting that FeII(EDTA)–NO reduction is the key to this process. This work investigated the performance, kinetics, and mechanism of FeII(EDTA)–NO reduction by Mn powder coupled with manganese ion (Mn2+) recovery. We initially studied the performance of FeII(EDTA)–NO reduction with respect to the major influencing factors (i.e., the particle size of Mn powder, initial FeII(EDTA)–NO concentration, Mn powder concentration, stirring speed, and temperature). Shrinking core model and Arrhenius law were applied to illustrate the kinetics and mechanism between FeII(EDTA)–NO solution and Mn powder, suggesting that the solid–liquid reaction was fitted on chemical reaction control, and the activation energy was calculated as 43.0 kJ mol–1. The effects of main operating parameters, such as precipitant concentration, pH value, and temperature, were studied on Mn2+ recovery. Results indicated that the pseudo-second-order model could precisely describe the kinetics of Mn2+ recovery. Finally, according to Arrhenius and Eyring–Polanyi equations, the reaction activation energy, enthalpy of activation, and entropy of activation for Mn2+ recovery were calculated as 17.25 kJ mol–1, 14.55 kJ mol–1, and 252.07 J (k mol)−1, respectively.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Yongheng Xiong,Yuting Li,Shipeng Wan,Yang Yu,Shule Zhang,Qin Zhong
Electrochemical reduction of NO to NH 3 (NORR) is an attractive approach to mildly realize NO removal and valuable NH 3 production. The electrolyte, as function as the NO absorbent, is crucial to apply electrochemical technology in practical de-NO engineering. In this paper, the ferrous chelate acted as the electrolyte for effective NO absorption in NORR based on the Brown-ring reaction. The rGO and Au/rGO catalysts served as cathodes to realize ferrous regeneration for continuous NO reduction. The results revealed that ferric chelate could be fully reduced at lower onset potential on rGO electrode. The Au/rGO catalyst exhibited excellent average yield and selectivity for NH 3 at − 0.1 V and pH = 6.32, (14.6 μmol* h −1 * cm −2 and 65.2%, respectively). The Faradaic Efficiency of NH 3 could reach 98.3% at pH = 1.0. This work provides a valuable reference for effective NO adsorption and sustainable NO-to-NH 3 conversion.
研究领域:
环境科学
·
电化学工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2017
·
IF 4.339
Baohuai Zhao,Rui Ran,Xingguo Guo,Li Cao,Tengfei Xu,Ze Chen,Xiaodong Wu,Zhichun Si,Duan Weng
Mn/Ce/Ti and Mn/Ce/Nb/Ti catalysts were synthesized using a precipitation method and their catalytic activities for NO selective reduction with NH 3 at low temperatures were evaluated. Nb doping not only improved the activity of the catalyst over a wide temperature range but also restricted the generation of NO 2 and N 2 O. The Mn/Ce/Nb/Ti catalyst displayed 100% NO conversion from 150 to 250 °C and >90% N 2 selectivity below 250 °C. The specific surface area of the catalyst was increased and its surface acidity was strengthened after Nb doping. Moreover, Nb doping increased the NO oxidation ability and lowered the NH 3 oxidation activity of the catalyst. All the above factors contributed to enhancing the overall NH 3 -SCR performance of the Mn/Ce/Nb/Ti catalyst compared with that of the Mn/Ce/Ti one. The long-term stability and resistance to H 2 O and SO 2 of the Mn/Ce/Nb/Ti catalyst were also evaluated.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Ruolan Li,Xingyan Liu,Yacen Tang,Jianning Yu,Ya Chen,Min Fu,Siqi Li,Youzhou He
In this study, a highly efficient bifunctional porphyrin-based MOFs with uniformly in-situ generated g-C 3 N 4 quantum dots (g-CNQDs) was fabricated for photocatalytic hydrogen evolution and NO removal, in which PtTCPP as the organic ligand and mixed Zr/Ti-oxo clusters as the metal nodes. Compared with most reported Zr-based porphyrin MOFs, the g-CNQDs@Zr-MOFs(Pt)(Zr/Ti) exhibited outstanding hydrogen evolution activity (14511.57 μmol g −1 ) and NO removal rate (31.9 %) under visible light irradiation. The obviously improved photocatalytic performance could be attributed to the significantly enhanced charge separation and transfer rates by the mixed Zr/Ti-oxo clusters via the rapid Ti 3+ /Ti 4+ process. Moreover, the uniformly in-situ generated g-CNQDs via confinement effect in the cavity of MOFs could also improve the utilization of visible light especially through the up-conversion effect, and promote charge carriers separation. This work provides an idea for us to expand the scope of light utilization and promote charge transfer and separation rates of MOFs via functionalizing host MOFs matrix and coupling guest active species to improve photocatalytic performance further.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Gangqiang Zhu,Mirabbos Hojamberdiev,Shaolin Zhang,Syed Taj Ud Din,Woochul Yang
In order to further improve its photocatalytic activity , the BiOI microspheres were activated by a synchronous coupling of Bi metal and graphene under solvothermal conditions. The effects of the synthesis temperature (160–200 °C) on crystallinity, morphology, and photocatalytic activity were studied in particular. As expected, the ternary Bi-BiOI/graphene photocatalyst synthesized at 180 °C exhibited higher photocatalytic activity for NO oxidation removal under visible light irradiation than individual BiOI, and binary Bi-BiOI and BiOI/graphene composites. The photocatalytic efficiency for the NO removal of the ternary Bi-BiOI/graphene photocatalyst synthesized at 180 °C reached 51.8% within 30 min of visible light irradiation. The enhanced photocatalytic activity of the ternary Bi-BiOI/graphene photocatalyst is attributed to (I) the efficient transfer of photo-generated electrons from BiOI and Bi to graphene, leading to the effective separation of the photo-generated electron-hole pairs and (II) the surface plasmon resonance effect of Bi nanoparticles in the composite photocatalyst. Furthermore, the results of the scavenger experiments and DMPO-ESR spin-trapping measurements reveal that O 2 − radical species play the most critical role and holes serve as a secondary active species in the oxidative removal process of NO by 180BOI/GR composite under visible light irradiation.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Tianxing Cui,Yumei Su,Xionghui Fu,Yi Zhu,Yuanming Zhang
Herein, we fabricated hydroxyl groups decorated Bi 4 O 5 I 2 nanosheets, and the contents of hydroxyl groups on the surface could be controlled by changing the reducibility of organic solvents. The stronger reducibility of organic solvents, the more hydroxyl groups on the surface. The hydroxyl groups on the surface of Bi 4 O 5 I 2 nanosheets have significant effects on photocatalytic activity. For degradation of organic pollutants, the surface hydroxyls form hydrogen bonds with organic pollutants, which is conducive to the adsorption of the substrates. For NO removal, the NO adsorbed on the hydroxyl groups is more oxidized into a toxic by-product NO 2 instead of NO 3 - , so less hydroxyl groups are important for photocatalysts towards NO removal. These new discoveries provide new insights to improve photocatalytic activities by modulating surface functional groups of photocatalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Ji Liu,Yuan-gu Xia,Meng-fan Liu,Bin Hu,Hong-jin Zhang,Ji-hong Li,Zhen-xi Zhang,Qiang Lu
Nitrogen oxides are the major pollutants in solid fuel/waste combustion processes, which can be reduced by unburned or additive chars. The surface char–NO reaction is significantly influenced by CO 2 , whereas the impact mechanism is far from conclusive. Herein, fixed-bed experiments and computational methods were adopted to elucidate the role of CO 2 on char–NO reaction. Experimentally, CO 2 exhibited an inhibitive impact on NO reduction at 873 K but a promotive influence at 1023 K and 1173 K. According to the detection of outlet CO, characterization of char, and density function theory (DFT) calculations, CO and gasified char derived from char–CO 2 gasification are both responsible for the promotive effect at 1173 K, which offers a clear image of the gasification mechanism conjectured in previous work. More importantly, a CO 2 -mediated oxygen rearrangement (CO 2 -MOR) mechanism has been found and confirmed for the first time, which can well explain the experimental results observed at 873 K and 1023 K. The adsorbed CO 2 can intervene in the oxygen rearrangement on the char surface to alter the NO reduction behaviors. The present study offers a comprehensive insight into the roles of CO 2 in the heterogeneous reduction of NO on char surface.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2024
·
IF 3.5
Wang Shuainan,Sheng Hongliang,Zhao Xiaoben,He Tao,Huang Yajun,He Song
The present investigation involved the preparation of N-doped high-specific surface porous activated carbon from lignin through hydrothermal carbonization, polymer premixing, and KOH activation. We looked at how the characteristics of lignin-based activated carbon were affected by the addition of polypyrrole and the alkali ratio. The addition of polymer polypyrrole as an N dopant during the activation process with KOH resulted in the N-doped biomass-based activated carbon with a greater pore size range, specific surface area, and pore volume, while also further encouraging the pore creation. Under the optimal preparation conditions, specifically hydrothermal treatment at 473 K and activation at 1073 K for 1 h, with a mass ratio of activator to carbon precursor of 4:1, the resulting activated carbon exhibited the highest BET surface area of 3415 m 2 /g and a total pore volume of 2.81 cm 3 /g. The various characteristics of activated carbon are examined using N 2 adsorption/desorption, scanning electron microscopy (SEM), elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Comparing this sample to other adsorbents, it was found that the material had a greater capacity for adsorbing gaseous benzene and NO. In static adsorption tests, the saturated adsorption of gaseous benzene reached 3338.75 and 2297.69 mg/g at 273 and 298 K, respectively, while the adsorption of NO reached 560.76 and 226.99 mg/g. Adsorption isotherms were used to analyze the experimental results, which were then fitted, examined, and assessed to look into the adsorption mechanism. The outcomes demonstrated the good adsorption performance of this sample as well as its promising and useful application potential in the removal of gaseous benzene and NO. Graphical
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-8
·
IF 5.578
Niu Xiaoyu,Zhao Tieying,Yuan Fulong,Zhu Yujun
The hollow CuO@SiO 2 spheres with a mean diameter of 240 nm and a thin shell layer of about 30 nm in thickness was synthesized using an inorganic SiO 2 shell coating on the surface of Cu@C composite that was prepared by a two-step hydrothermal method. The obtained hollow CuO@SiO 2 spheres were characterized by ICP-AES, nitrogen adsorption-desorption, SEM, TEM, XRD, H 2 -TPR, CO-TPR, CO-TPD and NO-TPD. The results revealed that the hollow CuO@SiO 2 spheres consist of CuO uniformly inserted into SiO 2 layer. The CuO@SiO 2 sample exhibits particular catalytic activities for CO oxidation and NO + CO reactions compared with CuO supported on SiO 2 (CuO/SiO 2 ). The higher catalytic activity is attributed to the special hollow shell structure that possesses much more highly dispersed CuO nanocluster that can be easy toward the CO and NO adsorption and the oxidation of CO on its surface.
研究领域:
材料化学
·
催化化学
·
纳米材料科学
·
环境催化
·
无机合成
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2025
·Vol. 39
·期 5
·e70148
·
IF 0
Han Zhang,Sisi Wang,Jingshu Ban,Hao Li,Le Ruan,Fushun Tang
In this paper, the NO adsorption performances of Ni-AIP MOF and Ni-AIP-BPY MOF synthesized by solvothermal method were compared, and the NO adsorption selectivity of two samples for the simulated flue gas conditions has also been studied. The results indicated that the Ni-AIP-BPY exhibited better NO adsorption performance with an NO adsorption capacity of 115.52 cc·g −1 at 100 kPa and ambient temperature and showed better adsorption selectivity with the highest adsorption selectivities of 937 and 10,691 for NO/CO 2 and NO/O 2 , respectively. Adsorption enthalpy calculations showed that Ni-AIP-BPY had a strong interaction force on NO, XPS and in-situ NO-FTIR results also confirmed that a strong adsorption occurred on the Ni metal center, and the main adsorptive products after NO adsorption were nitrate and nitrite. The introduction of a second ligand into the saturated coordination amine-containing complexes can improve the pore structure and coordination state of the materials, so that the complexes can activate unsaturated metal sites, thus significantly improving their adsorption and separation performance for NO gas molecules in flue gas. The results provided a new idea and understanding for the synthesis of materials for selective separation of NO components in flue gas.
研究领域:
环境科学
·
材料化学
✓ 已验证
产品关联
DOI
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Kean Chen,Binxian Chu,Qiuju Qin,Xuemei Ou,Runqi Zhao,Xiaoling Wei,Huan Wu,Bin Li,Lihui Dong
As an ideal substitute for the precious metals in the selective catalytic reduction of NO by CO, transition metal oxides perform very well. Thus, a series of CuO - Co 3 O 4 symbiotic oxide porous nanosheet catalysts are prepared with a CTAB-assisted hydrothermal method. Cu5 with the ratio of Cu and Co is 5 : 10, has the best activity on the premise of maintaining the nanosheet structure. Reduction pretreatment of Cu5 with H 2 is carried out, and the surface will be rapidly oxidized in air. In this period, Cu, CuO and Co 3 O 4 were produced and coexisted on surface. Cu5-re-163 exhibits greatly higher N 2 selectivity but a little inferior NO conversion. Further DFT calculation and characterizations proved that [N] free radicals exist during the reaction. The reaction on Cu5 and Cu-re-163 follow L-H and E-R mechanism respectively. [N] radicals on the latter are much easier to desorb, so that they are easy to combine with each other to form N 2 rather than with NO to generate N 2 O, as the reason why Cu5-re-163 has better selectivity.
研究领域:
催化化学
·
材料科学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yangyang Guo,Yang Zheng,Yue Peng,Tao Yue,Tingyu Zhu
Simultaneous removal of NO x and CO from steel sintering has attracted great attention because it is difficult to balance the catalyst reducibility and surface acidity merely using metal oxides or zeolite catalysts. In this study, a mixed CuMn-HZSM-5 catalyst was prepared via an impregnation method. The optimized sample exhibited excellent performance with 90% NO conversion and 100% CO conversion at 175 °C. The activity window of the catalyst was coincident with the actual demand of sintering flue gas control at 150-250℃. The active component CuMn suppressed the excessive Lewis acid sites on the zeolite support for NH 3 adsorption, while the reducibility of the catalyst also decreased compared with that of pure CuMn metal oxides . This synergistic effect was beneficial for the reduction of NH 3 nonselective oxidation with O 2 . In addition, both the DFT and DRIFTS results revealed that NO conversion was improved by CO introduction at low temperature, since NO could adsorb on the CO-preadsorbed sites for the reduction to N 2 via the O atoms of Mn 3c sites, i.e., adsorbed CO could also serve as a reductant to reduce NO to N 2 , which provides another reaction pathway in SCR reactions. Moreover, the NO 2 − and N 2 O 2 − species were observed in the spectra as key intermediates to oxidize CO to CO 2 , which are also the promoters for CO control.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）