Journal of Energy Storage
·
2022
·
IF 8.907
Zeyang Kang,Yaohui Shi,Hui Liu,Xiangyang Liu,Maogang He
Electrical generators transducing and concentrating solar power to heat and then to electricity require a material with good thermophysical properties to store heat when there is no sunlight. Here, LiCl-KCl-ZnCl 2 and LiCl-KCl-MgCl 2 were observed for their capacity to store energy by the change in sensible heat content as a function of temperature. The ternary phase diagrams of the two salts were predicted using a thermodynamic model . Three eutectic points for LiCl-KCl-ZnCl 2 and four eutectic points for LiCl-KCl-MgCl 2 were predicted and experimentally verified. The heat capacity and thermal stability of the seven eutectic mixtures were measured to evaluate their heat storage capacity and operating temperature range. LiCl-KCl-ZnCl 2 (13.86 % mol-40.63 % mol-45.51 % mol) and LiCl-KCl-MgCl 2 (47.29 % mol-44.33 % mol-8.38 % mol) were found to be the best choices for heat storage materials, which have low melting points of 451.8 K and 612.8 K, large heat capacity of 1.25 J/g·K and 1.80 J/g·K, and wide operating temperature range from room temperature to higher than 823 K, respectively.
研究领域:
材料科学
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热力学
·
能源工程
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产品关联
DOI
高影响因子
ACS Catalysis
·
2022
·
IF 13.7
Dongmiao Li,Jinni Shen,Jiangjie Zhang,Yao Chai,Yanyu Xie,Chengwei Qiu,Mengmeng Ni,Yuanhui Zheng,Xuxu Wang,Zizhong Zhang
The development of direct conversion for selective functionalization of inert methane plays an important role in the chemical sciences. Here, we report a photocatalytic approach to successfully convert methane into methyl chloride over NaTaO3 photocatalyst using an alkali chloride solution as the chlorine source under ambient conditions, which can overcome disadvantages of toxicity and corrosiveness in the traditional chlorination of methane. Various noble metals and oxide cocatalysts (Pt, Pd, Au, Ag, and Ag2O) and different chloride ion solutions (NaCl, KCl, LiCl, MgCl2, BaCl2, CaCl2, CuCl2, FeCl3, ZnCl2, etc.) are investigated to optimize the photocatalytic chlorination processes. Ag2O/NaTaO3 is the best photocatalyst, giving the maximum CH3Cl yield of 152 μmol g–1 h–1 in aqueous NaCl solutions and an apparent quantum yield of 7.2% under 254 nm monochromatic light irradiation. The target product CH3Cl is verified to be formed by a direct combination of the photoinduced species •CH3 and •Cl on the Ag2O surface. This work provides a meaningful approach for the conversion of methane into chloromethane under normal conditions.
研究领域:
化学科学
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环境科学
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产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2022
·Vol. 53
·期 4
·2634-2646
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IF 2.872
Huang Jingdong,Sohn Il,Kang Youngjo,Yang Xiao
Earth’s commercial and affordable zinc reserves are expected to be depleted in less than 50 years. Since electric arc furnace (EAF) dust contains a certain amount of Zn, recovery of Zn from EAF dust has become an important issue to assure a sustainable resource supply in the future. The key technical challenge is that Zn mainly occurs in EAF dust as ZnFe 2 O 4 , a very stable crystal which is difficult to reduce or leach. MgCl 2 is believed to be effective in breaking the structure of ZnFe 2 O 4 . This work investigates the fundamentals of the reaction between MgCl 2 and ZnFe 2 O 4 . Experiments show that Zn in ZnFe 2 O 4 is chlorinated to ZnCl 2 quickly with priority over Fe, implying the efficacy of MgCl 2 in separating Zn and Fe in ZnFe 2 O 4 by selective chlorination. Effects of MgCl 2 /ZnFe 2 O 4 molar ratio and temperature on the reaction are clarified. Overuse of MgCl 2 slows down the reaction and is detrimental to the selective chlorination of Zn. Temperature can effectively increase the reaction rate as well as the priority of chlorinating Zn. Utilization of MgCl 2 could be high, because evaporation of MgCl 2 is not as fast as the reaction with ZnFe 2 O 4 . According to these results, a new technology to recover Zn from EAF dust by using MgCl 2 is proposed.
研究领域:
冶金工程
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材料科学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Jinxiu Lou,Lu Yin,Feilong Dong,Zhanfei He,Huijie Lu,Shuangxi Fang,Xiangliang Pan
Nitrogenous disinfection byproducts (N-DBPs) are notorious for their serious health risks, yet nitrate (NO 3 - ) mediates N-DBPs generation during UV/chlorine treatment remains unexplored. This study investigated the interaction of chlorine and NO 3 - on N-DBPs formation and developed a specific fragment-based screening method using UPLC-QTOF-MS to explore the underlying mechanism. Results showed that the chlorine-to-nitrogen (Cl/NO 3 - -N) molar ratio significantly affects dichloroacetonitrile (DCAN) and dichloroacetamide (DCAM) generation, with peak concentrations at a Cl/NO 3 - -N molar ratio of around 15. NO 3 - promotes the production of HO • , which positively correlates with DCAN and DCAM concentrations, also peaking at this ratio. Utilizing our developed method, three key hydroxyl-substituted intermediates that circumvent the previously reported “limiting-steps” in DCAN formation were identified. This reaction proceeds via a stepwise mechanism involving hydroxylation and chlorine substitution to produce hydroxyl-phenylacetonitrile and hydroxyl-chlorine-phenylacetonitrile. The conversion rate of hydroxyl-chlorine-phenylacetonitrile to DCAN was 8.6 times higher at Cl/NO 3 - -N molar ratio of 15 compared to conditions without NO 3 - , attributed to the weakened bond strength of the side chain, as supported by density functional theory calculations. This study provides novel insights into the mechanistic pathways of DCAN and DCAM formation, critical for developing more effective drinking water disinfection technologies to control N-DBPs.
研究领域:
环境科学
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饮用水处理
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化学动力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers of Environmental Science & Engineering
·
2023
·Vol. 17
·期 11
·1-12
·
IF 6.4
Chen Meiling,Yin Mengjie,Su Yuetan,Li Ruizhe,Liu Kezhou,Wu Zhongbiao,Weng Xiaole
Despite the large emission of chlorinated volatile organic compounds (CVOCs) into the atmosphere, the ultimate fate of these compounds remains largely unknown. Herein, we explore the photochemical conversion of an important class of CVOCs, namely chlorobenzene (CB), on mineral α-Fe 2 O 3 particulates under atmospheric relevant conditions. A series of chamber reactions composed of the CB with/without SO 2 or NO 2 are performed, followed by in situ diffuse reflectance infrared Fourier transform spectroscopy measurements and density functional theory calculations. We show that CB can be considerably degraded by α-Fe 2 O 3 under light irradiation, whereas the reaction is markedly suppressed by adding SO 2 or NO 2 owing to their competitive adsorption and surface acidification. In particular, we discover that CB can be ultimately converted into polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) under dark state or light irradiation, suggesting a possible origin of atmospheric PCDD/Fs from this overlooked photochemical source.
研究领域:
大气科学
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环境化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yuxin Li,Zhiqiu Qu,Chao Shan
Sulfidation and nitridation have been reported as promising methods to modify nanoscale zero-valent iron (nZVI) for water decontamination from chlorinated organic compounds (COCs). However, the effects of sulfidation/nitridation on the reactivity of nZVI towards COCs of different polarities were poorly understood. To explore such effects, nZVI, one-step sulfided nZVI (S 1 -nZVI), two-step sulfided nZVI (S 2 -nZVI), and nitrided nZVI (N-nZVI) were prepared in this study, and chloramphenicol (CAP), florfenicol (FF), and sucralose (SUC) were employed as typical COCs with sequentially increasing polarities. Sulfidation and nitridation significantly enhanced the hydrophobicity of nZVI as observed from water contact angle. Anaerobic condition favored FF degradation by all the four nZVI-based materials, while sulfidation and nitridation could inhibit the competition effect of coexisting nitrate on FF removal by nZVI. The reactivity of the nZVI-based materials towards FF followed the same order of water contact angle, while sulfidation/nitridation did not enhance the reactivity of nZVI towards CAP. Intriguingly, sulfidation/nitridation was found to improve the activity of nZVI for dechlorination reactions during FF and CAP degradation, and N-nZVI exhibited particularly high dechlorination capability (∼90 % for FF and ∼100 % for CAP). In contrast, all the investigated nZVI-based materials had no activity in SUC degradation, indicating the negligible role of sulfidation/nitridation in promoting the reactivity of nZVI towards COCs of strong polarity. In addition, SUC may serve as a recalcitrant target compound to examine the reactivity of modified nZVI materials. This study sheds light on the development of nZVI modification strategies/methods for more efficient water treatment.
研究领域:
环境科学
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水处理
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Baoqiang Hao,Yang Guo,Xueling Bai,Renyuan Zhang,Xiaoqing Li,Jing Li
The combined application of chlorination and UV irradiation has the potential to yield important benefits in water treatment. However, much of the fundamental chemistry that governs the behavior of UV/chlorine systems have not been well defined. Cyano-containing pesticides (CNPs) are widely used in agriculture and inevitably enter surface waters and other aquatic environments. In this study, twenty CNPs and their intermediates were investigated to evaluate the formation of disinfection byproducts under chlorination and UV/chlorine systems. It was found that UV/chlorine can significantly enhance the generation of cyanogen chloride (CNCl) and dichloroacetonitrile (DCAN) compared to chlorination alone. The CNCl and DCAN concentrations increased from an average of 0.13 and 0.12 μM during the chlorination alone to 0.85 and 0.41 μM, respectively, when UV 254 light was introduced. The maximum yields of CNCl and DCAN could reach 31.8 % and 7.7 %, respectively. Both the photo-induced • OH and • Cl played a key role in the generation of CNCl and DCAN. Additionally, higher yields of total CNX were observed in the UV/chlorine system in the presence of bromide. Similar results were obtained in the treatment of actual water samples, in which the concentrations of CNCl and DCAN increased by orders of magnitude under UV/chlorine treatment compared to the chlorination alone. The results showed that the cyano group of organic pollutants has a higher potential to be directly converted to toxic CNCl and DCAN under UV/chlorine treatment. The inclusion of this basic chemistry will deepen our understanding of UV/chorine water treatment technologies.
研究领域:
环境科学
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水处理化学
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毒理学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 7
·424
·
IF 3.8
Mingyue Liu,Gang Chen,Zhenjun Song,Zhicai He,Aiguo Zhong,Mei Cui
Catalytic dechlorination of organic chlorides by palladium (Pd) with HCOOH represents one of the most effective and promising techniques for environmental remediation. In this study, we adopted alkaline-modified porous natural sponge as support of a Pd nanocatalyst (Pd@M-Sponge) and HCOOH as a hydrogen source for the hydrodechlorination of florfenicol (FF),o-chlorophenol (o-CP), andp-chlorophenol (p-CP). Favorable conversion efficiency of FF,o-CP, andp-CP was achieved at 25 °C and atmospheric pressure attributed to the small diameter and high catalytic reactivity of the prepared Pd NPs, in addition to the slight internal mass transfer limitation of the prepared Pd@M-Sponge. High reaction rate constants were obtained even in the conditions of a low molar ratio of HCOOH top-CP (10:1) and a high concentration ofp-CP (500 mg/L). The prepared catalyst also demonstrated superior recyclability without any obvious decrease in catalytic reactivity in 20 successivep-CP dechlorination cycles. This work provides an ideal recyclable and cost-effective catalyst based on renewable and biocompatible natural material for the catalytic hydrodechlorination of chlorinated organic pollutants with formic acid and a new view for the exploration and designing of highly reactive and stable catalysts for hydrodechlorination.
研究领域:
环境科学
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催化
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纳米技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 4
·674
·
IF 3.06
Haodong Tang,Bin Xu,Meng Xiang,Xinxin Chen,Yao Wang,Zongjian Liu
Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.Keywords:activated carbon;hydrodechlorination;nitrogen doping;Pd
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 5
·787-791
·
IF 0.875
Tang Cen,Jin Yanxia,Wang Xiaoxia,Hu Gengshen,Xie Guanqun,Li Xiaonian,Luo Mengfei
The manufacture of 1,1-dichloroethylene(1,1-DCE) usually employs liquid phase method to perform the dehydrochlorination of 1,1,2-trichloroethane(TCE), where large amounts of high-concentration salty wastewater is produced inevitably. It has been a long-term goal to achieve the gas phase synthesis of 1,1-DCE via supported catalysts. In this work, the gas-phase synthesis of 1,1-DCE from TCE was studied in the presence of pentaethylenehexamine( PEHA) supported on silica. High and stable selectivity to 1,1-DCE(up to 98%) was obtained, which could be ascribed to the relatively strong basicity of PEHA according to a proposed E2 mechanism. The formation of PEHA chloride from the HCl generated in situ was detected and was considered to be the main reason for the deactivation of PEHA catalyst.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Pengze Zhang,Yangzhen Jin,Zhaobin Jiang,Guanqun Xie,Qunfeng Zhang,Xiaonian Li
Developing of non-metallic catalyst to replace metal catalyst is a meaningful and challenging direction. In this work, the non-metallic catalyst was synthetized successfully by loading ionic liquid onto the silica surface, which was applied for the gas-phase dehydrochlorination of 1, 1, 2, 2-tetrachloroethane. The 12%TPPC/SiO 2 (wt%) showed the best results with the conversion of 1, 1, 2, 2-tetrachloroethane reaching 100%. The selectivity of 1, 1, 2-trichloroethylene was 100%, and no deactivation was found during the evaluation period. The catalytic mechanism was investigated and possible reaction route was given, which was a reference for fabricating and design of solid base catalyst.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS ES&T Engineering
·
2025
·
IF 6.7
Baoqiang Hao,Renyuan Zhang,Genye He,Zishi An,Xiaoqing Li,Jing Li
The combined application of UV254 irradiation and chlorination (UV/chlorine) is considered to be a promising method for the disinfection and removal of organic pollutants. However, it is not clear how this process affects the formation of disinfection by-products (DBPs). In this study, the formation of DBPs from 11 of the most commonly used azoles in the UV/chlorine process has been investigated. The study demonstrated that dichloroacetylene, a previously unreported DBP, was identified as a coproduct of azoles. In addition to dichloroacetylene, another toxic DBP, cyanogen chloride (CNCl), was also detected in the process. However, neither dichloroacetylene nor CNCl was detected in the presence of azoles during chlorination alone. The results indicated that •OH and •Cl radicals resulting from UV/chlorine were the key factors in the production of dichloroacetylene and CNCl. Further studies have shown that dichloroacetylene was relatively stable in water with a hydrolysis half-life of 77 h and can be degraded in the presence of UV irradiation or high doses of chlorine. Additionally, bromochloroacetylene was observed in the UV/chlorine system in the presence of bromide. Furthermore, the presence of dichloroacetylene was detected in real UV/chlorine-treated water samples at concentrations ranging from 0.06 to 0.18 μM. This was found to be significantly increased by the addition of pyrazole, as was the case with CNCl. Dichloroacetylene and CNCl were detected in wastewater treatment plants at concentrations ranging from 0.15 to 0.31 μM. This finding suggested that the active species of the UV/chlorine process may alter the DBP formation pathway and lead to the emergence of novel toxic DBPs that have not yet been identified.
研究领域:
环境科学
·
公共卫生
·
化学工程
✓ 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）