JOURNAL OF RARE EARTHS
·
2022
·
IF 4.632
Yandi Cai,Peng Yang,Qinglong Liu,Kaili Ma,Wenxin Ma,Wang Song,Qiuhui Qian,Fei Gao,Wei Tan,Lin Dong
Sulfation treatment has been widely used to promote the catalytic performance of ceria (CeO 2 ) based catalysts for the selective catalytic reduction of NO by NH 3 (NH 3 -SCR of NO). Praseodymium oxide (PrO x ), another commonly used rare earth material with similar structural properties as CeO 2 , also shows satisfactory redox properties due to the facile redox cycle of Pr 3+ ↔ Pr 4+ . In this work, gas phase sulfation treatment with varied duration was performed on PrO x at 200 °C, and the NH 3 -SCR activity of sulfated PrO x was evaluated. Based on the results of systematic characterizations (e.g., N 2 -physisorption, NH 3 oxidation , NO oxidation, in situ diffuse Fourier transform infrared spectroscopy), it is revealed that the catalytic performance of sulfated PrO x is highly dependent on the sulfation time (or the amount of sulfate species deposited on PrO x ), which has a significant impact on the competitive reaction between NH 3 oxidation and NH 3 -SCR of NO, thus determining the NH 3 -SCR activity of PrO x . This work provides new insight into tuning the interaction between PrO x surface and reactants (NO, NH 3 ) via sulfation treatment, which cam guide the design and application of PrO x based catalysts for NH 3 -SCR of NO in the future.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Runping Wu,Qing Ye,Kai Wu,Shuiyuan Cheng,Tianfang Kang,Hongxing Dai
The alkali metal (M = Na, K, Rb, and Cs)-modified C-FDU-15 (M-C-FDU-15( x ); x was the M/C-FDU-15 M ratio, and equal to 0.01–0.03) samples were prepared through an in situ process, and characterized by means of the TG, XRD, TEM, EDS, N 2 adsorption–desorption, O 2 -TPD, and CO 2 -TPD techniques. The (NO + O 2 ) adsorption mechanism was investigated using the (NO + O 2 )-TPD and DRIFTS techniques. The results show that the sequence of (NO + O 2 ) adsorption performance was Na-C-FDU-15(0.01) (104.1 mg/g) > K-C-FDU-15(0.01) (92.4 mg/g) > C-FDU-15 (76.2 mg/g) > Rb-C-FDU-15(0.01) (65.1 mg/g) > Cs-C-FDU-15(0.01) (62.3 mg/g). The alkali metal was uniformly distributed in C-FDU-15 and its doping enhanced the amount of the basic sites in the sample. Moreover, the optimal Na/C-FDU-15 M ratio was 0.02. (NO + O 2 ) were chemically adsorbed mainly in the forms of nitrite (NO 2 − ) and nitrate (NO 3 − ) on M-C-FDU-15( x ). A more amount of NO was converted to nitrate than to nitrite. There were three key factors of enhancing the (NO + O 2 ) adsorption capacity of C-FDU-15 due to alkali metal doping: the first factor was the increasing of surface area and pore volume of the sample, the second one was the enhancement in amount of the active sites in the sample, and the third one was the smaller alkali metal ionic radius in the sample.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Liwei Ma,Shihua Zheng,Guoqiang Li,Xuejun Wang,Kangdi Chen,Guojie Zhang
Fe(II)EDTA can remove NO efficiently, but it has not been industrially applied. This is because the oxygen present in the flue gas will oxidize Fe(II)EDTA and Fe(II)EDTA-NO to Fe(III)EDTA and deactivate them. In order to solve this problem, this paper innovatively proposes to use NaHS to reduce Fe(III) EDTA, because NaHS has high reducing ability and low price. Therefore, a series of experimental conditions were explored in order to obtain the best reaction setup. The results indicate that increasing the concentrations of NaHS, temperature, and pH enhances the rate of NaHS reduction. The mechanism of the increase in reduction rate was studied in depth using potentiometric titration. It was found that an increase in OH - concentration will generate S 8 precipitate, which is beneficial to the forward progress of the reaction and promotes the large-scale production of the active component Fe 2+ . Oxygen is an inevitable factor in actual flue gas, so this study innovatively proposed a kinetic model under aerobic conditions and used this model to predict the trend of Fe(III)EDTA reduction by NaHS. On this basis, NO removal experiments were conducted under high oxygen conditions. After 15 cycles, the reduction performance of NaHS was still very high, and the NO removal rate was higher than 70%. The reason for this phenomenon is that the stabilizer exists in a form that is conducive to the removal of NO by the active component Fe 2+ . Therefore, this study provides theoretical guidance for promoting the industrial application of Fe(II) EDTA technology for NO removal.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Pingping Xie,Xin Yong,Yongdan Li,Shetian Liu,Cuijuan Zhang
The 5%BaCoO 3 -CeO 2 catalysts show excellent catalytic performance for NO direct decomposition; however, the reasons for the high activity remain to be explored. Here, the catalyst was prepared by different methods (citric acid–nitrate one-pot method, impregnation method and mechanical mixing method), aiming to reveal the factors determining the catalytic activity. The results show that the one-pot derived materials display superior activity and oxygen resistance, which is stemmed from the smaller grains and uniform distribution of components, higher surface area, larger interface, better redox activity, faster oxygen desorption kinetics and better NO sorption capability. The catalytic mechanism was discussed based on the diffuse reflectance infrared Fourier transform spectroscopy and kinetic study . This work demonstrates that the one-pot method is promising to synthesize high performance heterogeneous catalysts and the derived 5%BaCoO 3 -CeO 2 is a competitive candidate for NO direct decomposition.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Hongyuan Xi,Song Zhou,Zhao Zhang
A novel method based on a Na 2 S 2 O 8 /urea composite system was used to both synchronously absorb SO 2 and NO from marine diesel engine emissions and reduce the nitrate residues in cleaning wastewater. In the Na 2 S 2 O 8 /urea solution, a temperature of over 60 °C and a Na 2 S 2 O 8 concentration of >0.05 mol/L were found to fully absorb SO 2 by overcoming the SO 2 release and effectively absorb NO. Urea successfully reduced the residual nitrate concentration and improves NO absorption at a concentration below 2 mol/L. The NO and SO 2 removal efficiencies reached 97.8 ± 1.5% and 100%, respectively, at 70 °C in 0.1 mol/L Na 2 S 2 O 8 and 1.5 mol/L urea solutions. The residual nitrate concentration was 8.12 ± 0.25 mg/L, far below the regulatory limit of 60 mg/L. Acidic conditions (pH ≤ 5.5) could be conducive to absorbing NO and reducing the residual nitrate concentration. Based on the experimental results, this novel method is highly promising for reducing ship emissions.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 14
·5580-5589
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IF 5.287
Zijian Feng,Jianqiang Wang,Xiao Liu,Yanwei Wen,Rong Chen,Hongfeng Yin,Meiqing Shen,Bin Shan
A series of LaxSm1−xMn2Oδ (x = 0, 0.1, 0.3, 0.5) catalysts were synthesized through a co-precipitation method. The catalytic activity for NO oxidation was enhanced with La substitution, and the maximum activity was achieved at x = 0.3. XRD and HRTEM results revealed the formation of a multiphase oxide as well as the interface structure between the mullite (SmMn2O5) phase and Mn-rich perovskite (La0.96MnO3.05) phase. The main impact of different La/Sm molar ratios is the amount of surface adsorbed oxygen (Oads) and surface Mn4+ ions as revealed by XPS results. The NO oxidation performance was enhanced through La addition by promoting the decomposition of nitrate/nitrite species and desorption of NO2, improving the reducibility of surface adsorbed oxygen, as determined by H2-TPR, NO + O2-TPRD and in situ DRIFTS studies. Mono-, bi-dentate and bridged nitrates formed on the surface were determined to be the primary reaction intermediates.
研究领域:
催化化学
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材料科学
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环境化学
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表面科学
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无机化学
✓ 已验证
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Zhanzhi Ge,Yuesong Shen,Sasa Gu
The catalyst for selective catalytic reduction of NO x at high temperatures is significantly demanded by current gas-fired exhaust purification. In this work, the complex oxides composed of two different structures of ZrO 2 -WO 3 and WO 3 /ZrO 2 with zirconium as the main component were prepared for NH 3 -SCR of NO at high temperatures by blending method and equal volume impregnation method, respectively. Combined with XRD, NH 3 -TPD, FE-SEM, BET and in situ DRIFTS characterization, the effects of component optimization of two kinds of ZrO 2 and WO 3 complex oxides on the performance for NH 3 -SCR of NO were mainly studied. The optimal compatibility of ZrO 2 and WO 3 complex oxides was determined, and the corresponding N 2 selectivity and anti-interference ability of water vapor and SO 2 were further investigated. Results showed that the performance of ZrO 2 -WO 3 prepared by blending method for NH 3 -SCR of NO was significantly better than that of WO 3 /ZrO 2 prepared by impregnation method. The ZrO 2 -WO 3 containing 20% WO 3 has the best performance in NH 3 -SCR of NO with NO conversion higher than 90% and N 2 selectivity higher than 90% at 450–650 °C, and the performance was not affected by SO 2 , slightly affected by competitive adsorption of water vapor at 450 °C and not disturbed by water vapor above 500 °C. Further investigation showed that the NH 3 -SCR of NO over the ZrO 2 -WO 3 reaction followed both L-H and E-R mechanisms. Characterization analysis revealed that ZrO 2 -WO 3 has finer microscopic particles, larger specific surface area, higher acid amount and stronger acid strength than WO 3 /ZrO 2 .
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Lei Chen,Wenting Sun,Zhiying Xu,Minghui Hao,Baojing Li,Xin Liu,Jingjing Ma,Liang Wang,Chunhu Li,Wentai Wang
Low-temperature electrocatalytic reduction of nitric oxide (NORR) is promising for the low-cost, high-efficiency removal and utilization of nitric oxide (NO), which couples the two crucial industrial processes of denitration and synthetic ammonia. We reported a binary catalyst of Cu/P–TiO 2 for NORR process, which took advantages of the Cu electrocatalysts and porous TiO 2 . The increase of surface areas and channels can improve the adsorption of NO molecules. The decoration of the ultrafine Cu nanoparticles on the porous TiO 2 may prevent the agglomeration of ultrafine Cu nanoparticles. The as-prepared Cu/P–TiO 2 electrode exhibits excellent electrocatalytic activity with a Faraday efficiency of 86.49% and NH 3 yield of 3520.80 μg·h −1 ·mg −1 in 0.1 M K 2 SO 4 at −0.3 V vs. RHE. The mechanism of the NORR reaction process with Cu/P–TiO2 catalysts was also discussed. This research may broaden the application areas of TiO 2 -based materials in the electrocatalysis and provide a new sight in the treatment of NO pollutants.
研究领域:
材料科学
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环境科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Qian Zhang,Yuanyu Shi,Xianjin Shi,Tingting Huang,Shuncheng Lee,Yu Huang,Jun-ji Cao
Photo-oxidative NO x removal often encountered with sluggish charge carrier separation kinetics and poor selectivity. Herein, Pd/ferroelectric Bi 4 Ti 3 O 12 nanoflakes (Pd/BTO NF) were constructed to investigate the photo-excited charge separation, O 2 activation and the generated reactive oxygen species (ROS) in dictating NO removal. Results showed that the depolarization field of ferroelectric BTO NF significantly promoted bulk charge separation, leading to boosted NO removal reaction kinetics (10 times higher) for Pd/BTO NF comparing with Pd/TiO 2 . Revealed by electronic paramagnetic resonance and radical scavenging tests, it is observed that the primary O 2 activation species differed among Pd, Ag and Pt supported BTO NF photocatalysts, which resulted in different selectivity. The underlying mechanism of NO photo-oxidative conversion pathway was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy. This work illustrate that metal/ferroelectric interfaces can be tuned to obtain differing O 2 activation species, and notable selectivity changes in photocatalysis mediated environmental remediation reactions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zhinian Liu,Guojun Li,Mingjia Zhang,Chen Zhang,Wangsheng Zheng,Xiangting You,Shule Zhang,Qin Zhong
The lack of compactness in heterojunction interfaces and poor charge separation is a great challenge in developing high-efficiency heterojunction photocatalysts . Herein, a novel Bi 4 Ti 3 O 12 -BiPO 4 heterojunction was successfully prepared for the first time by epitaxial growth of BiPO 4 on the surface of Bi 4 Ti 3 O 12 nanosheets . The optimized Bi 4 Ti 3 O 12 -BiPO 4 -0.5 increased the NO oxidation efficiency to 73.05%, surpassing pure Bi 4 Ti 3 O 12 (63.45%) and BiPO 4 (8.35%). Experiments and theoretical calculations indicated that the closely contacted heterointerface between BTO and BPO promoted the generation of the built-in electric field, which led to the formation of the Z- scheme transfer pathway for the photogenerated carriers . Therefore, the separation of photogenerated carriers was facilitated while retaining high redox potential , generating more ·O 2 – and ·OH to participate in NO oxidation. Furthermore, the adsorption of NO and O 2 was enhanced by introducing BiPO 4 , further improving the photocatalytic NO oxidation performance. This work emphasizes the critical role of heterointerface in accelerating charge transfer, providing a basis for the design and construction of tightly contacted heterojunction photocatalysts .
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Yin Tang,Wen Cui,Songxia Wang,Fan Dong
Though photocatalytic purification of NO has been widely studied, how to avoid secondary pollution during gas-solid reaction is still a challenge, especially in inhibiting the formation of toxic intermediates (NO 2 ) and avoiding the blow away of powdery photocatalyst. Herein, we proposed a one-step solvothermal method to prepare melamine sponge (MS) supported and functionalized g-C 3 N 4 (CN), which simultaneously realizes the inhibition of NO 2 formation and catalyst loss. Sodium hydroxide , which plays a dual role, has been introduced during the preparation of supported photocatalyst. Specifically, sodium atom, as the modifier of performance, could facilitate the randomly distributed charge of pristine CN to be converged, which accelerates the adsorption/activation of reactants for efficient and deep NO oxidation . Hydroxyl group, as the binder between CN and MS, induces the interaction by forming hydrogen bonds , which contributes to the firm immobilization of powdery photocatalyst. The supported sample exhibits outstanding NO removal rate (58.90%) and extremely low NO 2 generation rate (1.41%), and the mass loss rate of photocatalyst before and after reaction is less than 1%. The promotion mechanism of performance also has been elaborated. This work takes environmental risks as a prerequisite to propose a feasible strategy for perfecting the practical application of photocatalytic technology .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 6
·1755-1765
·
IF 2.482
Meng Fanyu,Zhang Mingjia,Zhou Fayang,Zou Haocheng,Zhu Boming,Zeng Yiqing,Zhang Shule,Zhong Qin
Abstract CrO x /black-TiO 2 catalysts were prepared by ligand-assisted (citric acid, oxalic acid and ethylenediaminetetraacetic acid) impregnation method. These catalysts were characterized in detail by means of X-ray diffraction, Raman, BET, X-ray photoelectron spectroscopy, H 2 and O 2 (NO) temperature programmed reduction or desorption and in-suit DFTIR spectra. The results indicated that ligands assistance was beneficial for CrO x interacted with oxygen vacancies and O–Ti–O structures. Among all the catalysts, CrO x /black-TiO 2 /CA (modified by citric acid) revealed excellent catalytic activity and stability for NO oxidation in the temperature range of 200–450 °C. The characterization results exhibited that the interaction existed between CrO x and oxygen vacancies resulting in more Cr 6+ . Moreover, the strong interaction between CrO x and O–Ti–O was attributed to the modification of carboxylic acid, which increased the content of Cr 3+ and chemical adsorption oxygen. High content of chemical adsorption oxygen promoted the adsorption ability of O 2 , and Cr 6+ enhanced the adsorption capacity of NO. Hence, chemical adsorption oxygen and Cr 6+ synergistically promoted the NO oxidation. Graphic Abstract
研究领域:
催化材料科学
·
环境化学
✓ 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）