ENERGY & FUELS
·
2024
·
IF 5.2
Wenbo Jia,Yueyuan Wang,Shaohua Ling,Liren He,Binghe Chen,Songtao Liu,Chuanmin Chen,Yue Cao
Fast selective catalytic reduction (SCR) atmosphere can significantly improve the NOx removal activity of VWTi catalysts, while the catalytic performance and reaction pathway of Hg0 oxidation in a fast SCR atmosphere are still unclear. In this paper, the catalytic activity of simultaneous NOx removal and Hg0 oxidation over VWTi catalysts in a simulated fast SCR atmosphere was investigated for the first time. The results showed that VWTi catalysts possessed a wide NOx removal active temperature window and a high Hg0 oxidation activity in a fast SCR atmosphere. The X-ray photoelectron spectroscopy (XPS) and Hg temperature-programmed desorption (Hg-TPD) methods were used to investigate the Hg0 oxidation process over VWTi catalysts in a fast SCR atmosphere. Combined with the homogeneous Hg0 oxidation experiment results, two domination reaction routes of Hg0 oxidation over VWTi catalysts in a fast SCR atmosphere were proposed. One was that the adsorbed Hg0 could react with the surface active species to form HgO. The other reaction route was a gaseous homogeneous route that the gaseous Hg0 could be oxidized directly to Hg(NO3)2 by gaseous NO2. Particularly, the gaseous homogeneous Hg0 oxidation process could notably weaken the inhibition effect of NH3 on Hg0 oxidation, thus improving the Hg0 oxidation activity of VWTi catalysts in a fast SCR atmosphere.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Chenhui Hu,Chunhong Liu,Kaimin Du,Chengkai Pang,Zuoxi Zhuo,Qiangsheng Gao
An energy-saving catalyst 4%Fe/Ce-Mn-TiO 2 was prepared via a simple one-step impregnation-annealing process and used as a denitration catalyst at low temperature (≤180 °C) and high water content (∼20%). The results show that 4%Fe/Ce-Mn-TiO 2 catalyst exhibits good low-temperature catalytic activity and water resistance attributed to its highly dispersed metal oxide species, more surface-adsorbed oxygen and high stability of particles. The denitrification efficiencies of 4%Fe/Ce-Mn-TiO 2 catalyst are 90% (5% H 2 O) and 70% (20% H 2 O) at 170 ℃ respectively, which are superior to the commercial vanadium catalyst in service usually needs heating up to 220 ℃.
研究领域:
环境科学
·
催化
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Peng Zhang,Yu Huang,Yongfang Rao,Meijuan Chen,Xinwei Li,Wingkei Ho,Shuncheng Lee,Junji Cao
Bulk materials with a microporous structure are adverse to light adsorption, photoelectron and reactant transport in a photocatalytic reaction. Mesoporous photocatalysts have shown many marked advantages in photocatalytic fields. Herein, uniform mesoporous Bi@Bi 2 O 3 nanospheres were fabricated by HCl–ethanol chemical etching at low temperature (60 °C). The obtained mesoporous photocatalysis increased the NO removal efficiency (16%) and inhibited toxic NO 2 generation (3%) under visible light irradiation. Further oxidation of Bi and calcination at high temperatures were avoided during template removal. Moreover, the as-prepared sample possessed a remarkably narrower pore size distribution (3.2–3.9 nm) and stronger light and NO adsorption ability than the bulk microporous Bi@Bi 2 O 3 . Work function and the electron spin resonance test results also indicated that the position of the entire energy bands on Bi 2 O 3 was lowered. The amount of reactive oxygen species generated over the uniform mesoporous structure was higher than that over bulk Bi@Bi 2 O 3 . However, photoelectrochemical measurements indicated that the separation efficiencies of the photo-generated carriers were not improved over the uniform mesoporous Bi@Bi 2 O 3 . Comprehensive studies have shown that the oxidation ability rather than the enhanced separation efficiency of charge carriers accounted for the enhanced photocatalytic activity. This work elucidates the roles of a uniform mesoporous structure in NO x photocatalytic oxidation and provides an efficient strategy for structural engineering in preparing highly reactive and practical photocatalysts.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Huawang Zhao,Yingnan Zhao,Mengke Liu,Xianghui Li,Yuhan Ma,Xin Yong,Hong Chen,Yongdan Li
Phosphorus is introduced to modify the Cu-SSZ-13 catalyst via incipient wetness impregnation, with P/Cu-SSZ-13 = 1 and 2 wt.%, and Si/Al = 4, for selective catalytic reduction of NOx with NH 3 . N 2 physisorption and XRD results show the incorporation of phosphorus as phosphate acid enhanced the hydrothermal stability of Cu-SSZ-13 significantly, during hydrothermal aging in 10 vol.% H 2 O/air at 750 °C for 16 h. NMR and Raman results suggest that phosphate ions migrate and coordinate with the framework-bonded Al species, forming a framework silicoaluminophosphate interface, thus impeding further dealumination and structure collapse. Before the hydrothermal aging, the isolated Cu 2+ ions partly interact with the phosphate ions, forming Cu-phosphate species and reducing the SCR performance. Nevertheless, the appropriate content of phosphate ions can prevent the structure collapse caused by the hydrothermal aging, remaining the isolated Cu 2+ ions as well as excellent SCR performance.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Minghu Zhao,Jiuhu Zhao,Ran Ding,Rongshu Zhu,Haiyan Li,Zhi Li,Jingwen Zhang,Yongji Zhu,Huiying Li
The existence of sulfur dioxide and water vapor in the flue gas generated from waste-to-energy stations could lead to catalyst deactivation , which has adverse effects on NO x removal. It is thus particularly important to study the reaction mechanism of catalyst resistance to poisoning. Herein, we report the mechanism of In-Co 3 O 4 -Ga 2 O 3 /H-Beta catalyst to SO 2 and H 2 O resistance in the selective catalytic reduction (SCR) of NO x by CH 4 . The catalyst could achieve 74.6% NO x removal efficiency in the presence of 100 ppm SO 2 and 5% H 2 O. In this catalyst, Co 3 O 4 is attributed to enhancing the reversible poisoning of SO 2 and CH 4 activation and increasing the number of Brønsted acid sites by decomposing H 2 O. However, the InO + active center was still eroded by a small amount of water vapor, leading to a reduction in NO x removal efficiency. The addition of Ga 2 O 3 primarily provided an important intermediate NO 2 for CH 4 -SCR reaction and reduced the aggregates of Co 3 O 4 to increase the exposure of indium sites, and could reduce a part of SO 2 to S 2− . This study provides a good candidate for preparing catalysts with superior resistance towards SO 2 and H 2 O for CH 4 -SCR.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Yang Zhang,Baihe Sun,Lin Jiang,Jiahui Fan,Fangjie Qin,Zhuo Liu,Jue Wang,Kan Kan,Keying Shi
A facile polymer heat treatment and reflux method are used for developing growth of flower-like BiOCl (BiOCl NFs) on 3D honeycomb-like N-doped graphitic carbon (N-GC) to form BiOCl/N-GC composites. The N-GC hierarchical structure effectively heightened the dispersion of BiOCl NFs, which increased the contacted area for the NO x gas molecule. Benefiting from the hierarchical structure, the (102) plane of BiOCl has a suitable adsorption energy for NO x , synergistic effect of large specific surface area and mesopores of N-GC, the formation of p-p heterojunctions , Bi–C interfacial bond, N-doping and the role of chemisorbed oxygen. The BiOCl/N-GC composites have satisfactory response and selectivity for NO x gas at room temperature. It reveals an exceptionally excellent response and response time of 52.54 and 3.2 s for NO x gas. It also exhibits a low detection limit (10 ppb) and a long-stability of 12 weeks. Thus, the BiOCl/N-GC nanocomposites are one of the most potential materials in gas sensor.
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
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Beilong Lin,Ziyang Guo,Jianhan Li,Gaofei Xiao,Daiqi Ye,Yun Hu
It is a major challenge to achieve effective synergistic reduction of NO x and VOCs in coal-fired flue gas under complex working conditions. In this work, V-Cu bimetallic oxide catalysts with different supports were designed. V1-Cu5 bimetallic oxide supported on TiO 2 showed significantly higher activity for simultaneous toluene oxidation and NO x reduction than that supported on ZSM-5, SiO 2 and γ-Al 2 O 3 . Meanwhile, it exhibited excellent stability and anti-poisoning performance, and could block the formation of toxic polycyclic aromatic hydrocarbons in by-products. Compared with ZSM-5, SiO 2 and γ-Al 2 O 3 , TiO 2 as support was conducive to the formation of abundant acidic sites and oxygen vacancies. In addition, the strong interaction between the metal active sites and TiO 2 accelerated the electron transfer from Cu to adsorbed O 2 , thus promoting the formation of active O 2− . This work can provide guidance for the development of catalysts designed for the simultaneous catalytic removal of NO x and VOCs.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 21
·20575-20590
·
IF 2.8
Lu Pei,Yue Huifang,Xing Yi,Wei Jianjun,Zeng Zheng,Li Rui,Wu Wanrong
In this study, series of Ce x Zr y Mn z O 2 /r-Al 2 O 3 catalysts were prepared by impregnation method and explored to co-purification of NO x and Hg 0 at low temperature. The physical and chemical properties of the catalysts were investigated by XRD, BET, FTIR, NH 3 -TPD, H 2 -TPR, and XPS. The experimental results showed that 10% Ce 0.2 Zr 0.3 Mn 0.5 O 2 /r-Al 2 O 3 yielded higher conversion on co-purification of NO x and Hg 0 than the other prepared catalysts at low temperature, especially at 200–300 °C. 91% and 97% convert rate of NO x and Hg 0 were obtained, respectively, when 10% Ce 0.2 Zr 0.3 Mn 0.5 O 2 /r-Al 2 O 3 catalyst was used at 250 °C. Moreover, the presence of H 2 O slightly decreased the removal of NO x and Hg 0 owing to the competitive adsorption of H 2 O and Hg 0 . When SO 2 was added, the removal of Hg 0 first increased slightly and then presented a decrease due to the generation of SO 3 and (NH 4 ) 2 SO 4 . The results of NH 3 -TPD indicated that the strong acid of 10% Ce 0.2 Zr 0.3 Mn 0.5 O 2 /r-Al 2 O 3 improved its high-temperature activity. XPS and H 2 -TPR results showed there were high-valence Mn and Ce species in 10% Ce 0.2 Zr 0.3 Mn 0.5 O 2 /r-Al 2 O 3 , which could effectively promote the removal of NO x and Hg 0 . Therefore, the mechanisms of Hg 0 and NO x removal were proposed as Hg (ad) + [O] → HgO (ad), and 2NH 3 /NH 4 + (ad) + NO 2 (ad) + NO (g) → 2 N 2 + 3H 2 O/2H + , respectively.
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研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Hafiz Muhammad Adeel Sharif,Muhammad Bilal Asif,Yuwei Wang,Ya-Nan Hou,Bo Yang,Xu Xiao,Changping Li
Iron (Fe)-based catalysts are widely used for taming nitrogen oxides (NO x ) containing flue gas , but the regeneration and long-term reusability remains a concern. The reusability can be acquired by external additives, and resultantly can not only increase the cost but can also add to process complexity as well as secondary pollutants. Herein, a self-sustainable material is designed to regenerate the catalyst for long-term reusability without adding to process complexity. The catalyst is based on reduced graphene-oxide impregnated by Fe 2 O 3 -MnO (rGO@Fe 2 O 3 -MnO; G-F-M) for spontaneous intra electron (e - )-transfer from Mn to Fe. The developed catalyst; G-M-F exhibited 93.7% NO x reduction, which suggests its high catalytic activity . The morphological and structure characterizations confirmed the Fe/Mn loading, contributing to e - -transfer between Mn and Fe due to its conductivity. The synthesized G-F-M showed higher NO x reduction about 2.5 folds, than rGO@Fe 2 O 3 (G-FeO) and rGO@MnO x (G-MnO x ). The performance of G-M-F without and with an electrochemical system was also compared, and the difference was only 5%, which is an evidence of the spontaneous e - transfer between the Mn and Fe-NO x complex. The designed catalyst can be used for a long time without external assistance, and its efficiency was not affected significantly (<3.7%) in the presence of high oxygen contents (8%). The as-prepared G-M-F catalyst has great potential for executing a dual role NOx removal and self-regeneration of catalyst (SRC), promoting a sustainable remediation approach for large-scale applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
JiaYu Chen,Peng Fu,Daofei Lv,Yang Chen,Meiling Fan,Junliang Wu,Amogh Meshram,Bin Mu,Xiang Li,Qibin Xia
A high-performance denitration catalyst based on Mn-Ce mixed-oxide derived from a specific Mn/Ce precursorwas fabricated by solvothermal method. It exhibited outstanding low-temperature activity, which achieved above 90% NO x conversion in the temperature of 150–310 °C. Remarkably, Mn-Ce mixed-oxide demonstrated a much better SO 2 tolerance, in which the NO x conversion increased from 92.6% to 97.8% at 150 °C after introducing 200 ppm SO 2 . The synthesized Mn-Ce mixed-oxide has a porous structure with abundant chemisorbed oxygen spices and exposed active sites. In addition, the increased acidity and redox capacity enhanced the catalytic activity after introducing SO 2 . Meanwhile, the injection of SO 2 separates NH 3 adsorption sites from oxidation agents, inhibiting the unwanted oxidization of ammonia to nitrogen oxides. Furthermore, the reaction pathway on Mn-Ce mixed-oxide proved to be the L-H mechanism based on in situ DRIFTS. Thus, the synthesized Mn-Ce mixed oxide demonstrated an excellent denitration performance and the especially high SO 2 tolerance, showing great potential for low-temperature NH 3 -SCR.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
Environmental Progress & Sustainable Energy
·
2025
·
IF 2.3
Zhengxiong Jiang,Zhitao Han
With the aim to develop wet denitration process for marine application, it is still challenging to simultaneously achieve high-efficiency NO x removal from flue gas and low nitrate concentration in scrubbed solution. Herein a novel two-step method was proposed to solve this issue: phosphate buffer solution (PBS) with organic additive was used to absorb NO x efficiently from flue gas, and in next step, Na 2 SO 3 as a reductant was added in the scrubbed solution to reduce NO x off-line. Five typical organic additives were chosen to compose with PBS. The tetrabutylammonium bromide and phosphate buffer solution (TBAB/PBS) composite solution exhibited superior NO x absorption performance. Furthermore, the effects of TBAB concentration, NO x oxidation degree, solution pH, temperature and O 2 concentration on NO x absorption performance of TBAB/PBS composite solution were investigated systematically, and a high NO x absorption efficiency of >90% could be achieved. It was mainly attributed to a physical complex between PBS and NO 2 , N O 3 − $$ N{O}_3^{-} $$ , N O 2 − $$ N{O}_2^{-} $$ , together with a mass transfer enhancement by TBAB. A long-run test showed that nitrate concentration was much lower than the limit value of IMO. Cyclic absorption and regeneration tests confirmed that Na 2 SO 3 could effectively regenerate the scrubbed solution in the absence of O 2 .
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 NANOPARTICLE RESEARCH
·
2019
·Vol. 21
·期 4
·1-7
·
IF 2.009
Xie Chong,Shi Jian-Wen,Yang Shenghui,Li Xifei
The MnO x -TiO 2 /MWCNTs nanocomposites were used as De-NO x catalysts to study the deep-rooted reason for the deactivation. Based on a series of characterization on as-prepared catalyst and poisoned catalyst, the results showed that the chief culprit for the deactivation is the micropores in the De-NO x catalyst. The formed ammonium (bi)sulfate in the micropores during the SCR reaction process could not be took away by the gas flow soon and then deposited on the catalyst surface gradually, and further covered the active sites. And the poisoned catalysts could be recovered partly rather than fully by heat treatment at 500 °C because of the decomposition of the ammonium (bi)sulfate and the phase transition of the TiO 2 .
研究领域:
环境催化
·
纳米材料科学
·
大气污染控制
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）