CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Yanke Yu,Jinsheng Chen,Jinxiu Wang,Yanting Chen
A series of CuSO 4 /TiO 2 catalysts were prepared using a wet impregnation method. The activity of each sample in the selective catalytic reduction of NO by NH 3 (NH 3 -SCR) was determined. The effects of SO 2 and H 2 O, and their combined effect, on the activity were examined at 340 °C for 24 h. The catalysts were characterized using N 2 adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy, temperature-programmed reduction of H 2 (H 2 -TPR), temperature-programmed desorption of NH 3 (NH 3 -TPD), and in situ diffuse-reflectance infrared Fourier-transform spectroscopy (DRIFTS). The CuSO 4 /TiO 2 catalysts had good activities, with low production of N 2 O above 340 °C. SO 2 or a combination of SO 2 and H 2 O had little effect on the activity, and H 2 O caused only a slight decrease in activity during the experimental period. The NH 3 -TPD and H 2 -TPR results showed that CuSO 4 increased the amounts of acid sites and adsorbed oxygen on the catalyst. In situ DRIFTS showed that the NH 3 -SCR reaction on the CuSO 4 /TiO 2 catalysts followed an Eley–Rideal mechanism. The reaction of gaseous NO with NH 3 adsorbed on Lewis acid sites to form N 2 and H 2 O could be the main reaction pathway, and oxygen adsorption might favor this process.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Zhimin Hao,Juntao Wu
A complex air pollution environment requires filters to be multifunctional. Nanofibrous materials with surface-loaded metal–organic frameworks (MOF-fibers) are reasonable structures for multifunctional air filtration. These materials can not only utilize the network structure of fibers to intercept particulate matter (PM) but also retain the porous structure of the MOFs to adsorb toxic gas. Epitaxial growth methods are commonly utilized to prepare MOF-fibers but are uneconomical and time-consuming. Herein, a facile self-assembly strategy is developed to prepare zeolitic imidazolate framework-polyimide (ZIF-PI) nanofibers with an interconnected network structure and high porosity for air filtration applications. Due to their unique structure, the ZIF-PI nanofibrous membrane exhibited high PM2.5 filtration efficiency and enhanced SO2 adsorption capacity. Moreover, by exploring the morphology evolution of the ZIF-PI nanofibrous membrane, a possible “synergistic effect of hydrophobic and electrostatic force” self-assembly mechanism was demonstrated.
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
MOLECULES
·
2023
·Vol. 28
·期 7
·3068
·
IF 4.6
Yuanyuan Ma,Wanting Liu,Zhifang Li,Yuhang Sun,Mingyuan Shi,Zheng Nan,Ruotong Song,Liying Wang,Jingqi Guan
TS-1 zeolite with desirable pore structure, an abundance of acidic sites, and good thermal stability promising as a support for the selective catalytic reduction of NO with NH3(NH3-SCR). Herein, a series of Mn–Fe/TS-1 catalysts have been synthesized, adopting tetraethylenepentamine (TEPA) as a metal complexing agent using the one-pot hydrothermal method. The introduced TEPA can not only increase the loading of active components but also prompts the formation of a hierarchical structure through decreasing the size of TS-1 nanocrystals to produce intercrystalline mesopores during the hydrothermal crystallization process. The optimized Mn–Fe/TS-1(R-2) catalyst shows remarkable NH3-SCR performance. Moreover, it exhibits excellent resistance to H2O and SO2at low temperatures. The characterization results indicate that Mn–Fe/TS-1(R-2) possesses abundant surface Mn4+and Fe2+and chemisorbed oxygen, strong reducibility, and a high Brønsted acid amount. For comparison, Mn–Fe/TiO2displays a narrower active temperature window due to its poor thermostability.Keywords:Mn-Fe/TS-1;one-pot synthesis;NH3-SCR;metal complexing;resistance to H2O and SO2
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yuting Hu,Minghu Zhao,Bo Du,Ting Cheng,Zhaozhong Jiang,Kai Qin,Chengzhu Zhu
A series of M-MnCeO X catalysts using MOF (Metal-organic Framework) were prepared to apply for NH 3 -SCR (Selective Catalytic Reduction) of NO X . The effects of Mn/Ce molar ratio, calcination temperature and its activity including catalytic activity, H 2 O/SO 2 resistance and stability were systematically investigated. The results showed that under the Mn/Ce molar ratio of 1 and calcination temperature of 400 ℃, the catalyst exhibited excellent catalytic activity, H 2 O/SO 2 resistance, and stability. When the concentration of NO was 500 ppm, the gas spatiotemporal velocity (GHSV) was 36,000 h −1 , and the reaction temperature was 100 ℃, the NO conversion efficiency of M-MnCeO X exceeded 90.0 %. Added 200 ppm SO 2 and 3 vol% H 2 O simultaneously, the NO conversion efficiency was close to 80.0 %. By analyzing the physicochemical properties of the catalyst, M-MnCeO X had a large specific surface area, numerous acidic sites, and excellent redox properties. According to density functional theory (DFT), the NH 3 /NO adsorption energy of M-MnCeO X were −2.35 and −2.40 eV, exhibiting lower than a single MOF-derivative, promoting the adsorption of NH 3 or NO. The reaction mechanism on the M-MnCeO X catalyst followed the E-R and L-H mechanisms by In situ DRIFTS.
研究领域:
环境催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
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2022
·
IF 11.072
Jiajin Huang,JiaYu Chen,Jinze Yao,Siyao Zhao,Xingbei Wu,Qibin Xia
The challenge for selective catalytic reduction (SCR) of NO x with NH 3 is to improve de-NO x activity at low temperatures while simultaneously improving the tolerance of catalysts towards SO 2 poisoning. Herein, V and Ce oxides were loaded on deactivated SCR catalysts subjected to acid pickling (CAT) via impregnation to recover de-NO x activity. The resulting V–Ce@CAT catalyst exhibited 85–95% NO x conversions over a wide temperature window of 200–450 °C while conversions of only 40–78% over the same temperature range were observed with CAT (spent catalyst treated with acid). Interestingly, in addition to the high tolerance towards SO 2 displayed by V–Ce@CAT, the catalyst exhibited improved reactivity after the introduction of 200 ppm SO 2 , with the NO x conversion increasing from 80% to 87%. The results indicated that a kinetic equilibrium was reached between the formation and decomposition rates of Ce 2 (SO 4 ) 3 on V–Ce@CAT which prevented the accumulation of surface sulfate species, thereby protecting the main active species V from catalytic inactivation. Furthermore, in situ DRIFTS revealed that the NH 3 -SCR reaction pathway of V–Ce@CAT follows the L-H mechanism.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ATMOSPHERIC ENVIRONMENT
·
2025
·
IF 3.7
Yu Lu,Lingdong Kong,Jiandong Shen,Beibei Liu,Yixuan An,Yuwen Wang,Jie Tan,Lin Wang
H 2 O 2 -driven oxidation has been considered to be the main cause of sulfate formation in haze events. However, field observations have confirmed that the known H 2 O 2 sources cannot explain its ambient levels. In this study, the photochemistry of acetylacetone (AA), a ubiquitous β-diketone in the atmosphere, was investigated under ultraviolet (UV) irradiation using droplets formed in-situ by deliquescence of hygroscopic ammonium sulfate ((NH 4 ) 2 SO 4 ) and sodium dihydrogen phosphate (NaH 2 PO 4 ). Special emphasis was placed on elucidating its contributions to H 2 O 2 formation and SO 2 oxidation under varying conditions. Results show that AA photolysis significantly boosted H 2 O 2 production. In (NH 4 ) 2 SO 4 droplets, H 2 O 2 peaked early after UV irradiation, while in NaH 2 PO 4 droplets, it reached fourfold higher and peaked later because phosphate promotes the AA photolysis. Hydrogen atom donors like citric acid redirected radical termination from H 2 O 2 to organic hydroperoxides (ROOHs). Cl − and Br − altered radical processes: Cl − suppressed H 2 O 2 production but enhanced ROOHs production, while Br − exhibits stronger, concentration-dependent effects on both species. SO 2 oxidation was achieved by various oxidizing species such as H 2 O 2 and ROOHs produced during AA photolysis. Key products such as pyruvic acid, peroxyacetic acid and propanedioic acid were identified and possible UV-driven reaction pathways were revealed. These results uncover new H 2 O 2 production and sulfate formation pathways, and show the complexity of aerosol-phase photochemistry. This work improves our understanding of atmospheric H 2 O 2 source and redox processes, offering new insights for the oxidation potential of atmospheric organic aerosols and atmospheric oxidation capacity, and enhancing atmospheric chemistry models to better predict air quality and climate.
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Mengyuan Zhang,Xiaoyan Lu,Kongliang Luo,Jian Ye,Jia li Dong,Nana Lu,Xiaopeng Wang,Qiang Niu,Pengfei Zhang,Sheng Dai
Ubiquitous presence of SO 2 usually shows adverse effects on industrial catalysis. Herein, a concept of engineering entropy to design SO 2 resistance oxide catalysts is proposed. (Ni 0.2 Mg 0.2 Cu 0.2 Zn 0.2 Co 0.2 )Fe 2 O 4 showed excellent performance (the CO 2 conv. = 41.4%, CO selec. = 99.6% at 400°C) compared to the control samples in the reverse water–gas shift (RWGS). In addition, (Ni 0.2 Mg 0.2 Cu 0.2 Zn 0.2 Co 0.2 )Fe 2 O 4 had the SO 2 -tolerant ability (the CO 2 conv. = 38.5%, CO selec. = 99.2% at 400°C) after being poisoned with 1000 ppm SO 2 at 400°C for 1 h. In sharp contrast, the control samples NiFe 2 O 4, MgFe 2 O 4, CuFe 2 O 4 and CoFe 2 O 4 lost their activity. O 1S XPS indicated that (Ni 0.2 Mg 0.2 Cu 0.2 Zn 0.2 Co 0.2 )Fe 2 O 4 had higher oxygen vacancy concentrations. SO 2 resistance mechanism was studied by infrared spectroscopy, SO 2 -TPD, in situ S 2p XPS and the DFT results, confirming that the low SO 2 adsorption energy of (Ni 0.2 Mg 0.2 Cu 0.2 Zn 0.2 Co 0.2 )Fe 2 O 4 , which was attributed to the lower Gibbs free energy. This work may inspire the rational design of SO 2 -resistant catalysts.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 5
·2090-2097
·
IF 3.269
Dongshun Deng,Yaotai Jiang,Xiaobang Liu
A series of furoate anion-functionized ionic liquids (ILs) were synthesized and applied as new absorbents for SO2. Results showed that these ILs possessed satisfactory performance for SO2 absorption. At 293.15 K, the maximum absorption capacity was 0.69 and 0.24 g SO2 per g P4442[FA] under 1.0 and 0.1 bar, respectively. The SO2 enriched ILs were easily regenerated by bubbling N2 at 343.15 K and recycled five times without obvious loss of absorption performance. The influences of temperature, SO2 partial pressure, and water content in ILs on SO2 absorption performance were systematically explored. The absorption capacity of ILs is discussed from aspects of the structure of cations, anions, and the interaction of cation–anion. The absorption mechanism was analyzed using NMR and FTIR methods. The selectivities of SO2/CO2, SO2/N2 and SO2/O2 were studied and [P4442][FA] achieved relatively high selectivity for SO2 compared to other gases. Present furoate ILs demonstrate potential application as a SO2 absorbent owing to their good performance.
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
BIORESOURCE TECHNOLOGY
·
2012
·
IF 4.98
Weina Liu,Yucui Hou,Weize Wu,Muge Niu,Wenhua Wang
Efficient pretreatment is important for complete enzymatic conversion of lignocellulosic materials. Pretreatment of wheat straw with sulfur dioxide (SO 2 ) dissolved in hot water achieved xylose and total product yields of up to 61.1% and 93.9%, respectively, based on the mass of lignocellulose in wheat straw. The apparent activation energies for hemicellulose conversion and xylose dehydration were 7.8 and 9.0 kJ/mol. FT-IR spectra of the residual solid after treatment showed that the hemicellulosic components were converted, the hydrogen bonds in cellulose were broken, but the lignin structure was not changed. Importantly, the SO 2 was recovered from the product mixture by steam stripping and could be reused. Thus, the SO 2 –H 2 O system is an efficient and environmentally friendly way for the conversion of hemicellulose in wheat straw into monosaccharides, such as xylose, glucose and arabinose.
研究领域:
生物化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2015
·
IF 2.679
Guoqiang Han,Yaotai Jiang,Dongshun Deng,Ning Ai
Five biobased solvents (BBSs) with high boil point, namely ethyl levulinate (EL), butyl levulinate (BL), dibutyl succinate (DBS), gamma-butyrolactone (GBL) and gamma-valerolactone (GVL), were applied in absorption of SO 2 . The solubilities of SO 2 in the BBSs were determined at temperatures (293.15 to 333.15) K and pressures (0 to 120) kPa. Henry’s constant and thermodynamic properties (standard dissolution Gibbs energy, dissolution enthalpy, dissolution entropy) were further calculated according to the solubility data. The gravimetric solubilities in BBSs changed with the sequence of GBL > GVL > EL > BL > DBS. The solubility of SO 2 and absorption enthalpy in present BBSs and other molecular solvents as well as ionic liquids (ILs) were systemically compared. The results illustrated that GBL and GVL possessed the potentiality to capture SO 2 among all absorbents due to their relatively large solubility and low absorption enthalpy for SO 2 , biodegradability, low toxicity, inexpensive cost and low viscosity.
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
SEPARATION SCIENCE AND TECHNOLOGY
·
2013
·
IF 1.164
Guangfei Qu,Jun Zhang,Junyan Li,Ping Ning
Two kinds of phosphate ionic liquids were synthesized and their SO2 absorption performance was investigated. It was found that both ionic liquids could readily absorb SO2, and the absorption capacity could reach 2.8 and 2.7 mol SO2 per mole ILs, respectively, at ambient temperature and under normal pressure. Moreover, the cycle of SO2 absorption and desorption from ionic liquids was repeated for four times and no change in the absorption capacity was observed. FT-IR spectrum and 1H NMR were used to characterize the microstructure of SO2-absorbed ILs and ILs, analysis showed that both ionic liquids absorbed SO2 purely by physical absorption. Comparing with the previous reported ionic liquids such as [Bmim][PF6] and [Emim][BF4], the synthesized ionic liquids showed higher absorption capacity, due to the anion based phosphate (O˭P‒O) with the free electrons on the oxygen interacting with the Lewis acidic sulfur of SO2, and then showing a great affinity for SO2.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2024
·
IF 14.4
Yiqun Cao,Jiarong Liu,Qingxin Ma,Chunyan Zhang,Peng Zhang,Tianzeng Chen,Yonghong Wang,Biwu Chu,Xiuhui Zhang,Joseph S. Francisco,Hong He
We present a novel mechanism for the formation of photocatalytic oxidants in deliquescent NaCl particles, which can greatly promote the multiphase photo-oxidation of SO2 to produce sulfate. The photoexcitation of the [Cl––H3O+–O2] complex leads to the generation of Cl and OH radicals, which is the key reason for enhancing aqueous-phase oxidation and accelerating SO2 oxidation. The mass normalization rate of sulfate production from the multiphase photoreaction of SO2 on NaCl droplets could be estimated to be 0.80 × 10–4 μg·h–1 at 72% RH and 1.33 × 10–4 μg·h–1 at 81% RH, which is equivalent to the known O3 liquid-phase oxidation mechanism. Our findings highlight the significance of multiphase photo-oxidation of SO2 on NaCl particles as a non-negligible source of sulfate in coastal areas. Furthermore, this study underscores the importance of Cl– photochemistry in the atmosphere.
研究领域:
大气化学
·
环境科学
✓ 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）