Catalysts
·
2020
·Vol. 10
·期 1
·72
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IF 3.52
Xiaopeng Zhang,Xiangkai Han,Chengfeng Li,Xinxin Song,Hongda Zhu,Junjiang Bao,Ning Zhang,Gaohong He
Sorbent of αMnO2nanorods coating TiO2shell (denoted as αMnO2-NR@TiO2) was prepared to investigate the elemental mercury (Hg0) removal performance in the presence of SO2. Due the core-shell structure, αMnO2-NR@TiO2has a better SO2resistance when compared to αMnO2nanorods (denoted as αMnO2-NR). Kinetic studies have shown that both the sorption rates of αMnO2-NR and αMnO2-NR@TiO2, which can be described by pseudo second-order models and SO2treatment, did not change the kinetic models for both the two catalysts. In contrast, X-ray photoelectron spectroscopy (XPS) results showed that, after reaction in the presence of SO2, S concentration on αMnO2-NR@TiO2surface is lower than on αMnO2-NR surface, which demonstrated that TiO2shell could effectively inhibit the SO2diffusion onto MnO2surface. Thermogravimetry-differential thermosgravimetry (TG-DTG) results further pointed that SO2mainly react with TiO2forming Ti(SO4)O in αMnO2-NR@TiO2, which will protect Mn from being deactivated by SO2. These results were the reason for the better SO2resistance of αMnO2-NR@TiO2.Keywords:core-shell structure;αMnO2nanorods;elemental mercury removal;SO2resistance
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Qihuang Huo,Yahui Wang,Huijun Chen,Yu Feng,Lina Han,Weiren Bao,Liping Chang,Jiancheng Wang,Kechang Xie
It is a win–win strategy to prepare mercury sorbents from low-cost high-sulfur raw materials. In part 1, mercury sorbents with excellent performance were prepared from high inorganic sulfur coal through KOH activation. However, this method does not work for high organic sulfur coal. In this work, a two-step preparation method is developed to prepare mercury sorbents from high organic sulfur coal. The first step is the co-pyrolysis/carbonization of Fe 2 O 3 and coal, during which organic sulfur in coal is converted into FeS x . XPS shows that the percentage of S x 2– /S on the surface of the carbonized samples gradually increases from 5.4% to 22.2% with the m(Fe):m(S o ) ratio from 0:4 to 5:4. The second step is KOH activation, and it converts FeS x into various S species, including C-S, S 0 , S 2 2− and S 2− . Among the prepared mercury sorbents, LF+3Fe/4S-A (m(Fe):m(S o ) = 3:4) shows the best mercury removal performance, and its mercury removal efficiency remains above 84% for 120 min under N 2 +O 2 at 120 °C. The Hg-TPDD and XPS results indicate that S*, including C-S, S 0 and S 2 2− , are the major active sites for mercury removal rather than Fe element, and HgS is the main existing form of mercury on the used sorbents. Besides LF coal, this two-step process is also applicable to other high organic sulfur coals (such as LL coal, WJZ coal, and SY coal) and high-sulfur petroleum coke.
研究领域:
环境科学
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2023
·
IF 5.7
Yongjin Hu,Zhichang Jiang,Runxian Wang,Shujie Gao,Hui Liu,Haining Wang,Dong Ye
In this article, the effects of K species, including K 2 O, KCl, and K 2 SO 4 , on the Hg 0 removal capability of MnO x /HZSM-5 adsorbent were investigated. Adding K 2 O and K 2 SO 4 interfered with the Hg 0 removal process; as the loading amount of these two K species increased, this adverse impact became more obvious. This was because the added K 2 O or K 2 SO 4 lowered the acidity and oxidizability of the adsorbents via the interactions with MnO x , which exerted an inhibitory effect on the adsorption and oxidation of Hg 0 . By contrast, introducing KCl made almost no adverse impacts on the Hg 0 elimination ability of the adsorbents. With rising the KCl content to 4 wt%, even ∼92.7% Hg 0 removal efficiency was obtained. This could be attributed to the presence of Cl − ; with the guidance of high-valence-state metal cations and O 2 , Cl − could be converted to active chlorine species, which was capable of transforming Hg 0 to HgCl 2 . This finding supplied a theoretical basis for developing new adsorbents that were capable of stably operating in the power plants with high-alkali-content coal utilized.
研究领域:
环境科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2022
·
IF 7.392
Xiaoqi Jiang,Qing Li,Wenjie Xia,Zhiwei Huang,Xiaomin Wu,Huawang Zhao,Zhilei Guo,Weixin Kong,Chung-shin Yuan,Guohua Jing,Huazhen Shen
Elemental mercury (Hg 0 ) is the most difficult mercury species to remove from the flue gas. Photocatalysts of transition metal oxide modified TiO 2 can effectively remove Hg 0 . However, the metal oxide easily aggregates into large nanoparticles, reducing the atom utilization efficiency and photocatalytic activity. We presented a facile strategy of employing g-C 3 N 4 as an anchor to successfully load highly dispersed ultrasmall CeO 2 clusters on g-C 3 N 4 /TiO 2 . Moreover, the mechanism of anchoring CeO 2 clusters and charge transfer of the ternary photocatalyst were explored in-depth. The results demonstrated that at 250 °C, the photooxidation efficiency of Hg 0 by CeO 2 -g-C 3 N 4 /TiO 2 was several times higher than that of CeO 2 /TiO 2 , TiO 2 , and g-C 3 N 4 . The cavity of the tri-s-triazine ring anchored small CeO 2 clusters via strong Ce-N coordination bonds. A combined type II and Z-scheme transport paths accelerated the separation of photogenerated electron holes. This research offers valuable surface engineering strategy for highly dispersed ultrasmall cluster decorated TiO 2 .
研究领域:
材料科学
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环境科学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2019
·
IF 6.361
Xia Zhang,Daolei Wang,Xiaokun Man,Jiang Wu,Qizhen Liu,Yongfeng Qi,Zhiqiang Liu,Xiaoyan Zhao,Jiaxi Wu,Chenyu Hao
The morphology of catalyst is a very important factor influencing the photocatalytic activity of the catalyst. Owing to its scientific and technological importance, controllable preparation of photocatalysts with different morphologies has been studied. In this work, BiOIO 3 /g-C 3 N 4 heterojunction composites are synthesized using hydrothermal method and the composites with different morphologies are fabricated by adjusting the amount of NaOH in precursor solutions to control the growth of BiOIO 3 crystal plane. The physicochemical properties of BiOIO 3 /g-C 3 N 4 heterojunction composites were investigated by XRD, XPS, FTIR, SEM, TEM, HRTEM, BET, UV–vis DRS and PL characterization. The effect of the BiOIO 3 morphology on the photocatalytic efficiency of BiOIO 3 /g-C 3 N 4 heterojunction composites was evaluated by photocatalytic removal of gas-phase Hg 0 under visible light irradiation. When the morphology of BiOIO 3 is regular square-like, BiOIO 3 /g-C 3 N 4 has the optimal removal efficiency 92.6% of Hg 0 . Finally, electron-hole migration path and photocatalytic mechanism of catalysts are proposed.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
·
IF 13.2
Xi Zhou,Yibing Xie,Lu Wang,Langlang Wang,Xiang Li,Ping Ning,Xueqian Wang
Graphene has recently emerged as a nano-functional material with great potential in the field of photocatalysts. Doping graphene quantum dots (GQDs) into CdS by a simple hydrothermal method led to a unique hexagonal CdS prism structure that assembled into nanospheres, simultaneously inducing intergranular Z -Scheme heterojunctions of the (001) and (100) plane families in CdS. As a result, the CdS-GQDs composite exhibited excellent removal efficiencies for gaseous mercury (Hg 0 ), exceeding 95% under visible light and 90% over photocatalytic cycles. Experimental and optical characterization results indicated that the photoresponse of the composite photocatalyst was broadened due to the doped GQDs. Furthermore, density functional theory calculations revealed that the formation of a Z -scheme heterojunction between the two crystal planes of CdS generated an internal electric field in CdS, resulting in a novel carrier transfer channel. Through GQD doping, this work successfully addressed the occurrence of serious photocorrosion in CdS, providing a novel composite dedicated to the efficient removal of Hg 0 from flue gas under visible light.
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Hailong Li,Weilin Zhang,Jun Wang,Zequn Yang,Liqing Li,Kaimin Shih
Simultaneous nitrogen monoxide (NO) reduction and elemental mercury (Hg 0 ) oxidation in the presence of ammonia (NH 3 ) was for the first time studied on a copper oxide/titanium dioxide (CuO/TiO 2 ) catalyst at low flue gas temperatures. More than 80% NO reduction and 90% Hg 0 oxidation were concurrently achieved on the CuO/TiO 2 catalyst at 250 °C under a simulated NH 3 selective catalytic reduction (SCR) atmosphere. NO was likely oxidized on the CuO/TiO 2 catalyst to form active nitrogenous species, particularly with the aid of oxygen. The active nitrogenous species then significantly promoted Hg 0 oxidation. NH 3 itself did not affect Hg 0 conversion on the CuO/TiO 2 catalyst. The co-occurrences of NO and NH 3 led to a reduction in oxidized mercury (HgO in this work), which partially offset the Hg 0 oxidation and therefore resulted in a relatively lower Hg 0 conversion efficiency. However, compared to flue gas without NO and NH 3 , the combined presence of NO and NH 3 still enhanced Hg 0 oxidation over the CuO/TiO 2 catalyst, primarily because of the overwhelming benefit from NO. This is superior to many other SCR catalysts, including commercial vanadia-based SCR catalysts, on which an SCR atmosphere generally inhibits Hg 0 conversion.
研究领域:
环境催化
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大气污染控制
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化学工程
·
材料科学
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环境化学
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工业生态学
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能源与环境技术
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
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2019
·
IF 3.021
Lingjun Ma,Caixia Yue,Liang Ye,Qihuang Huo,Lina Han,Liping Chang,Weiren Bao,Jiancheng Wang
Pd–Fe bimetallic sorbents were shown to be a great potential sorbent for Hg0 removal from coal-derived fuel gas. In this work, activated carbon (AC), Al2O3, and Beta molecular sieve were chosen as supports to disperse Pd–Fe bimetallic components. The effects of the supports on Hg0 removal of Pd–Fe bimetallic sorbents were evaluated using a fixed-bed reactor at 200 °C. The regeneration performance of sorbents was also investigated. The results showed that Hg0 removal activity and regeneration performance over Pd–Fe/AC was the best, followed by Pd–Fe/Beta, and Pd–Fe/Al2O3. The Hg0 removal efficiency of Pd–Fe/AC bimetallic sorbents remained above 80% within 400 min after regeneration 4 times. The Pd–Fe bimetallic sorbents were characterized by N2 adsorption–desorption, Fourier transform infrared spectroscopy, X-ray diffraction, CO pulse adsorption, Hg temperature-programmed thermal desorption, and X-ray photoelectron spectroscopy. The analysis results revealed that three sorbents had a similar Hg0 removal mechanism. Hg0 transformed to Pd–Hg amalgam and HgS after reacting with the sorbents. Pd0 and Fe2O3 were the active species for the removal of Hg0. The removal performance of Hg0 by Pd–Fe/Al2O3 sorbents was the lowest. It is because Pd–Fe/Al2O3 sorbents have the lowest specific surface area, surface content, and dispersion degree of the Pd component. Furthermore, Pd0 over Pd–Fe/Al2O3 sorbents was severely poisoned and transformed to PdS during the regeneration process.
研究领域:
环境科学
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材料科学
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能源工程
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
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2020
·
IF 3.421
Min Zhou,Jiang Wu,Huaning Wang,Dayong Guan,Xinfeng Dong,Jianmin Wang,Tao Jia,Qizhen Liu
Constructing a heterojunction and designing a band gap are effective methods to promote the efficiency of a photocatalyst and solar energy utilization. In this work, g-C3N4/Yb3+-Bi5O7I nanostructured photocatalysts were successfully prepared using a hydrothermal method with glycol as a solvent and a calcination method, and the performance of the photocatalysts containing different amounts of g-C3N4 was studied. A series of characterizations confirmed the successful complexation of g-C3N4 nanosheets with Bi5O7I, and Yb3+ was successfully doped into the lattice of Bi5O7I. g-C3N4 and Yb3+ have a synergistic effect on expanding the photoresponse range of CYB(g-C3N4/Yb3+-Bi5O7I) composite photocatalysts. As expected, CYB samples have wonderful photocatalytic performance and stability in the removal of Hg0, among which CYB-20 has the highest removal efficiency, reaching 79%. Yb3+ with upconversion characteristics can convert infrared light into visible light and form new energy levels in Bi5O7I. g-C3N4 and Bi5O7I form a Z-scheme heterojunction to improve the photocatalytic performance of Bi5O7I. Besides, the electron and hole transmission paths and the catalytic mechanism of the photocatalysts are also proposed. This work offers a new approach to construct a photocatalyst system for pollutant emission control with a wide wavelength range of sunlight, which may be helpful to develop environmentally benign functional materials.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
·
IF 8.6
Linzhi Shen,Ziwen Xiong,Zhaohui Du,Hao Wang,Wenrui Li,Zhen Zhang,Hao Wu,Changsong Zhou,Yaming Zhou,Guanghua Tang,Jing Liu,Hongmin Yang
M-N-C catalysts have considerable potential in the fields of catalysis, such as highly polluting gaseous elemental mercury (Hg 0 ) oxidation. However, the direct application of these kinds of catalysts for mercury removal is stymied by their low catalytic efficiency. Heteroatom-doping in M-N-C catalysts has been proposed as a powerful strategy to the promote catalytic of Hg 0 , but the origin of boosting catalytic activity is still elusive. Herein, it is disclosed that selenium doping induces an obvious electron-acceptor effect for accelerating the Hg 0 catalytic oxidation. The model selenium-doped Cu-N-C catalyst with atomically dispersed active sites was verified by various characterization methods, such as SEM-EDS and scanning transmission electron microscopy. The optimal Cu-NC-Se with Cu/Se ratio of 1:1 exhibited the best Hg 0 removal performance, over 8-fold enhancement in their Hg 0 oxidation capacities than raw selenium-free Cu-NC. At the optimal reaction temperature of 90 °C, Cu-NC-Se achieved an average Hg 0 removal rate of 92.44% within 60 min under single pure N 2 atmosphere. As for the influence of flue gas components, the presence of O 2 promoted the removal of mercury in Cu-NC-Se, whereas CO 2 , NO and SO 2 served as slight inhibitors. Even after five cycles of the experiment, the average mercury oxidization efficiency was still remained at 88.5%, showing that Cu-NC-Se can be reused with good maintenance of the catalytic activity and atomic dispersion of Cu and Se in the structure. The unsaturated Cu sites connected with pyridinic N on the carbon matrix can serve preferential adsorption to Hg 0 and doped selenium. Meanwhile, the selenium doping accelerated Hg 0 adsorption and accept sufficient electrons for promoting Hg 0 oxidation to forming stable HgSe, which is also corroborated by the theoretical analysis results based on density functional theory. This work not only provides an alternative facile synthetic strategy for developing heteroatom-doping atomically dispersed M-N-C catalysts, but also represents a significant advance for deepening the understanding of the Hg 0 catalytic oxidation mechanism on M-N-C catalyst.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shengyan Liu,Wensheng Lin,Ao Wang,Wei Chen,Liangying Yu,Chong Tian
The mass discharge of mercury from coal-fired power plant has caused great harm, abating mercury emissions is of preoccupation for protecting public environmental safety and human health. Metal oxides are often used for Hg 0 removal in the flue gas. In this paper, a hollow tubular MnO x (MnCot) was successfully prepared by rapid flame annealing using cotton fiber as a sacrificial template. The MnCot were then well characterized and tested for its capability for Hg 0 removal in flue gas. The results indicate that the flame assisted synthesis method for rapidly prototyping metal oxides with typical structures is achievable. The hollow tubular structure of the cotton fiber is well reprinted with good crystallization of Mn 3 O 4 . The inner diameter of the hollow tubular MnCot is about 10 μm, and the thickness of the tube is about 1 μm. The Hg 0 removal efficiency on MnCot can be maintained as high as 90 % under simulated flue gas atmosphere below 240°C. O 2 and NO have a positive effect on the Hg 0 removal, which can act as the fresh active sits thus enhancing its capability for Hg 0 removal. However, the presence of SO 2 will result in the surface sulfation on MnCot, thus deteriorating its capability for Hg 0 removal. Further, the competitive adsorption between SO 2 and Hg 0 on the material will also weaken its capability for Hg 0 removal. The hollow tubular MnO x rapidly prepared by one-step flame annealing has a good industrial application potential for Hg 0 removal in coal-fired flue gas.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 13
·13602-13618
·
IF 2.914
Yue Huifang,Lu Pei,Su Wei,Xing Yi,Li Rui,Wang Jiaqing
To optimize the simultaneous removal of NO x and Hg 0 , a series of Cu a Ce b Zr c O 3 /γ-Al 2 O 3 catalysts prepared by the impregnation method were explored and their physical and chemical properties were analyzed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), NH 3 -temperature-programmed desorption (NH 3 -TPD), H 2 -temperature-programmed reduction (H 2 -TPR), in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFT), and Fourier transform infrared spectroscopy (FT-IR). The results showed that 15% Cu 1.4 Ce 0.55 Zr 0.25 O 3 /γ-Al 2 O 3 resulted in the highest conversion efficiency for the simultaneous removal of NO x (93%) and Hg 0 (85%) at low temperatures (200 to 300 °C). Meanwhile, 15% Cu 1.4 Ce 0.55 Zr 0.25 O 3 /γ-Al 2 O 3 showed good stability and resistance to SO 2 and H 2 O, which is due to its low crystallinity, good textural performance, and strong redox ability. According to the TPD, TPR, and XPS results, the strong acidic character of 15% Cu 1.4 Ce 0.55 Zr 0.25 O 3 /γ-Al 2 O 3 promoted the removal of NO x and Hg 0 . The synergistic effect between CuO and CeO 2 in 15% Cu 1.4 Ce 0.55 Zr 0.25 O 3 /γ-Al 2 O 3 can increase the mobility of chemically adsorbed oxygen and activates lattice oxygen, leading to an excellent performance. The DRIFT results showed that NH 3 , NH 4 + , nitrate, and nitrite participated in the selective catalytic reduction (SCR) reaction. On the basis of our experimental results, Hg 0 and NO x removal mechanisms were proposed as Hg (ad) + O* → HgO (ad) and 2NH 3 /NH 4 + (ad) + NO 2 /NO 3 − (ad) + NO→2N 2 + 3H 2 O/2H + , respectively.
研究领域:
环境催化
·
大气污染控制
·
材料化学
·
表面科学
·
工业生态学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）