Environmental Science-Nano
·
2022
·Vol. 9
·期 9
·3407-3416
·
IF 9.473
Han Song,Xinwen Ou,Mengye Wang,Yan Zhang,Zhang Lin
H2 production during the transformation of Fe(OH)2 into magnetite (i.e., Schikorr reaction), has a significant impact on many environmental applications, including the long-term effectiveness of permeable reactive barriers composed of zerovalent iron and the stability of geological radioactive waste repository. However, the reactivity of the Schikorr reaction is not systematically evaluated and its chemical mechanism still remains controversial. Here, we investigate water reduction on the Fe(OH)2 surfaces with the help of an interface-reaction model between water and Fe(OH)2. The Fe(OH)2 hexagonal nanosheets prepared using a coprecipitation method possess dominantly exposed (001) and (100) facets. As unveiled by the DFT simulations, the (001) Fe(OH)2 facet only exposes OH, which is, therefore, inert to water reduction. Moreover, the active Fe-exposed (100) Fe(OH)2 facet is more thermodynamically favourable for water adsorption and dissociation than the (101) and (102) facets. However, the high energy barrier for water dissociation (2.79 eV) may restrict the rate of water reduction on the Fe(OH)2 facet. In addition, the capacity of (100), (101), and (102) Fe(OH)2 facets to adsorb OH− is stronger than that for H2O, which further inhibits water reduction. Furthermore, DOS calculations manifest that Fe d orbitals play a significant role in H2O adsorption, indicating that manipulating the electronic structure of the Fe site is a critical path to mediate water reduction in Fe(OH)2. Our study provides new insights into the understanding of the mechanism of the phase transformation of Fe(OH)2 under anaerobic conditions in environmental and earth sciences.
研究领域:
环境科学
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地球科学
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理论化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Shiliang Wu,Hongwei Yang,Jun Hu,Dekui Shen,Huiyan Zhang,Rui Xiao
In this work, the pyrolysis of furans (furan, 2-methylfuran, furfuryl alcohol , and furfural) have been checked by Py-GC–MS at 1100 °C to detect the decomposition of furans and the formation of benzene derivatives and PAH. From the Py-GC–MS results, different side chain functional groups on furan-ring lead to different kinds of products and product distributions, such as hydroxyl group leading to dimers, and aldehyde group leading to pyrans, but the mechanism for furan-ring opening and decomposition is universal for furans pyrolyzed in this study. In order to explain the experimental results and the formation of benzene derivatives and PAH, the formation of benzene from furan has also been calculated by B3LYP/6-31G + +(d,p). Two possible benzene formation mechanisms, Diels-Alder and acetylene reaction mechanism, have been proposed and calculated. By comparison, it has been regarded that Diels-Alder reaction was more possible for PAH formation as this mechanism has a lower activation energy for initiation step, but acetylene reaction mechanism was more possible for benzene formation as this mechanism has a lower global activation energy.
研究领域:
化学
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能源科学
·
环境科学
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2021
·
IF 8.001
Ying Li,Shengli Niu,Jun Wang,Wenbo Zhou,Yongzheng Wang,Kuihua Han,Chunmei Lu
A pure mesoporous SrTiO 3 with a honeycomb pore structure is synthesized by the sol-gel method and applied to catalyze transesterification of palm oil with methanol for the biodiesel production . The catalyst is characterized by XRD , CO 2 /NH 3 -TPD, N 2 adsorption-desorption, SEM-EDX, Raman and XPS to reveal its catalytic performances. The highest FAME yield of 93.14% is achieved in transesterification with the molar ratio of methanol to oil of 15:1 and catalyst concentration of 6 wt % at 170 C for 3 h. Besides, the catalyst is highly tolerant of FFAs and moisture, where the FAME yields of 83.80% and 86.50% are achieved even with the oleic acid and water addition of 10 wt % and 5 wt %. Meanwhile, the catalyst is found to be an effective catalyst for the simultaneous esterification and transesterification. The molecular simulation results show that the Ti sites are more easily attacked by FFAs and the Sr active sites are thus retained for the adsorption of methanol to catalyze transesterification, which explains the bifunctionality of the catalyst.
研究领域:
催化化学
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材料科学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Guo-chang Song,Xing-yu Yang,Zhong-wei Li,Qiang Song
Arsenic (As) pollutants are highly toxic and using Ca-based minerals to adsorb As 2 O 3 is effective for emission control. In this study, a fixed-bed experimental system was used to study the adsorption of As 2 O 3 by the mixture of CaO, SiO 2 , and Al 2 O 3 at 1200 °C. The amount of As adsorbed by multiple minerals was higher than that by single minerals, indicating enhanced adsorption of As 2 O 3 under the coupling effects of Ca, Si, and Al. The adsorption amount of As first increased and then decreased with an increase in the CaO:(SiO 2 +Al 2 O 3 ) and SiO 2 :Al 2 O 3 ratios. Adsorbed As was mainly enriched in Ca-Si-Al mineral, including Ca 2 Al 2 SiO 7 . Density Functional Theory calculation was conducted to study the As 2 O 3 adsorption on the Ca 2 Al 2 SiO 7 (0 0 1) surface. The analysis of Mulliken charge and density of states showed that As 2 O 3 molecules formed Al-O, O-As, and Ca-O bonds with the Al, O, and Ca sites. Si and Al in Ca 2 Al 2 SiO 7 enhanced the adsorption ability of Ca sites by promoting electron transfer . Si/Al ratio close to 1:1 is conducive to the formation of Si-O-Al structures, thus further enhancing the adsorption. The results can help optimize coal blending strategies and modify adsorbents to further reduce As emissions during coal combustion .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Xiong Peng,Zhijia Luo,Hongmei Xie,Wanwen Liang,Jinlu Luo,Chengxiong Dang,Aili Wang,Lihua Hu,Xiwen Yu,Weiquan Cai
Phenylarsonic acids are deemed as emerging contaminants, and their removal by carbonaceous materials has aroused wide attentions. However, the adsorption behaviors and mechanisms on nitrogen doped carbon still remain unclear. Herein, nitrogen doped porous carbons (NC-x) for adsorbing p -arsanilic acid and roxarsone were fabricated by hydrothermal and following activation treatment of peanut shell. The results revealed that NC-750 which was activated at 750 °C exhibited high BET surface area of 1331.11 m 2 /g, total pore volume of 0.97 cm 3 /g and average pore size of 2.91 nm, and its maximum equilibrium capacities based on Sips model for p -arsanilic acid and roxarsone were 287.3 mg/g and 462.6 mg/g, respectively. The sufficient adsorption space, rich defect structure and high affinity of nitrogen-containing groups endow NC-750 with high adsorption capacities, and the adsorption mechanisms involve with pore-filling, hydrogen bonding and π-π interactions. Density functional theory (DFT) calculation demonstrated that p -arsanilic acid was electron donor while roxarsone was electron acceptor, and graphitic nitrogen was conducive to the π-π interactions while pyrrolic nitrogen and pyridinic nitrogen were preferential for hydrogen bonding interactions. This work can provide reference for understanding the adsorption behaviors and interfacial mechanisms between phenylarsonic acid and nitrogen doped carbonaceous materials.
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Xinghong Qu,Hongxue Zeng,Yongsheng Gao,Dong Xu
In this study, phosphate/thermal activated peroxymonosulfate (PMS) process were applied to degrade the antiviral drug acyclovir (ACV) in water. Both Na 2 HPO 4 and Na 5 P 3 O 10 could effectively enhance ACV removal by thermally activated PMS process and the enhancement of Na 2 HPO 4 was more significant. High reaction temperature favored ACV removal and the best removal can be achieved at a certain PMS dosage in both processes. With increasing Na 2 HPO 4 dosage, the ACV removal first increased and then decreased, while increasing Na 5 P 3 O 10 dosage caused the enhancement of the degradation. The ACV degradation by Na 2 HPO 4 /thermal/PMS system was easily affected by initial solution pH, while Na 5 P 3 O 10 /thermal/PMS system operated in a wider pH range. The addition of Cl - and NO 3 - exerted insignificant effect in Na 2 HPO 4 /thermal/PMS process, while posed complicated impact by Na 5 P 3 O 10 /thermal/PMS process. The presence of HA significantly retarded ACV degradation by Na 2 HPO 4 /thermal/PMS system, while in Na 5 P 3 O 10 /thermal/PMS system, high HA concentration accelerated the degradation. In Na 2 HPO 4 /thermal/PMS system, SO 4 •- and •OH were identified as the main active species. Whereas, the ACV degradation was relied on non-free radicals ( 1 O 2 ) in Na 5 P 3 O 10 /thermal/PMS process. The strengthening effect of Na 2 HPO 4 was reflected in its ability to reduce the reaction energy barrier required for O-O bond cleavage in PMS molecules, while Na 5 P 3 O 10 provided an alkaline condition for the self-decomposition of PMS. 10 and 11 intermediate products were detected in Na 2 HPO 4 /thermal/PMS and Na 5 P 3 O 10 /thermal/PMS systems, respectively. Both processes produced intermediates with higher toxicity than ACV according to software analysis.
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2023
·Vol. 12
·期 15
·2888
·
IF 5.2
Tong Sun,Yitao Wang,Mingyue Li,Dong Hu
Phthalic acid esters (PAEs) are the most commonly used plasticizers, and long-term or high levels of exposure to PAEs have a huge potential risk to human health. In this study, the theories of Hartree–Fock (HF) and density functional theory (DFT) with different hybrid methods and basis sets were used to calculate the theoretical Raman spectra of five PAEs, and the comparison of calculated spectra between different theories, hybrid methods, and basis sets was conducted to determine the suitable theory with hybrid method and basis set for PAEs. Also, the Raman vibrations were assigned to the Raman peaks of PAEs according to the theoretical and experimental Raman spectra. The results indicate that DFT is more suitable for the theoretical study of PAEs than HF. In DFT, the hybrid method of B3LYP is more applicable to the theoretical study of PAEs than B3PW91, and the basis set of 6-311G(d, p) obtains the most consistent theoretical Raman spectra with the experimental spectra for PAEs. This study finds the optimal combination of the theoretical method and basis set for PAEs, and it will contribute to the establishment of the Raman fingerprint and the development of rapid detection for PAEs in the future.Keywords:PAEs;Raman;DFT;HF;theoretical study
研究领域:
化学
·
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Yuping Gai,Wei Deng,Junbo Hu,Dan Li,Wenshuo Xie,Xiang Li,Jingjing Zhang,Dewu Long,Fei Jiang
The preparation of stable electrocatalyst for oxygen evolution reaction is of the utmost importance to realize high performance water decomposition reaction . Metal-organic framework (MOF) nanostructures have become promising materials. Herein, we report three kinds of electrocatalysts with different structures and properties for the oxygen evolution reaction, which were constructed by using different binding sites of three kinds of ligands following a mechanism which involved only *O and *OH species as intermediates. CoFeBTC-MOF shows excellent overpotential η = 261 mV at 10 mA cm −2 (1.481 V vs. RHE), Tafel slope of 59.29 mV dec −1 and pretty excellent stability (48 h of continuous testing), making it become one of the best acid-resistant catalysts for oxygen evolution reaction. The DFT calculations show that there are different ways to transfer electrons . In addition, the coupling effect between Co and Fe metals is the key to regulate the electrocatalytic activity , confirming the cooperative catalysis mechanism with a reduced energy barrier.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jian Guan,Yuqi Liu,Qiuyi Zhu,Guojun Ma,Jiayu Zhang,Zheyong Fan,Wei Chen,Jiawei Yang,Ning Han,Yunfa Chen
At present, near-ground ozone still acts as an air pollutant, posing threats to human’s health. In this study, Fe-based catalysts with different coordination environments and valance states were synthesized and the coordination environments were verified using EXAFS and XRD Rietveld fitting, while in-situ Raman and in-situ DRIFTs were employed to investigate the oxygen intermediates of ozone catalytic reaction. The following activities order for ozone catalytic reaction was obtained: [FeO 6 ] 3+ ≫ [FeO 4 ] 3+ > [FeO 6 ] 2+ ≈ [FeO 4 ] 2+ proven by DFT calculations, and α-Fe 2 O 3 with [FeO 6 ] 3+ coordination structure has a high efficiency of about 80 % after 2 h at a WHSV of 720000 mL g -1 h −1 and ozone concentration of 1000 ppm. The superior catalytic activity could be attributed to the high crystal splitting energy in the octahedral coordination structure, which could offer electrons easily for the catalytic reaction. This study provides valuable insights for the development of Fe-based ozone catalysts as well as for other transition metal oxides.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2024
·
IF 3.3
Jingjie Tang,Luying Xie,Jiayu Liu,Shangyu Shi,Qikun Yang,Bo Zhang,Yingying Wang,Lin Chen,Shaohui Jia,Mingfang Ma,Zengyang Xie
Highly efficient and practical carbon–chalcogen (S, Se) and amide bonds formation methodologies for the synthesis of thio- and seleno-acetamides were developed, via the base-promoted one-pot two-step reactions of 2-amino(benzo)thiazoles and aryl acetyl chlorides with dichalcogenides. This cross-coupling reaction afforded the goal products that had been chalcogenated regioselectively in moderate to good yields. Further transformations of the new synthesized compounds, DFT calculations and preliminary mechanism studies are discussed as well.
研究领域:
有机化学
·
计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2024
·
IF 8.3
Li Wang,Jianfeng Zhang,Shixin Meng,Huiyong Wu,Yunze Zhao,Zhen Meng,Lei Feng,Huanting Wang,Yuan Cheng,Liangrong Yang,Huizhou Liu
The dissolution loss of extractant into aqueous solution during lithium solvent extraction from salt lakes poses a significant issue. We found that branched chains of neutral organophosphorus extractants provide suitable steric hindrance, enhancing lithium extraction efficiency and Li/Mg selectivity. Additionally, increasing the number of alkyl chains in organophosphorus extractants increases their hydrophobicity, thereby reducing extractant dissolution loss during the extraction process. Based on these findings, a novel extraction system comprising tri(2-ethylhexyl) phosphate (TOP), FeCl 3 , and 4-methyl-2-pentanone (MIBK) was explored. The extraction conditions, including the Fe/Li molar ratio, diluents, phase ratio, and stripping conditions, were thoroughly investigated and optimized. The extraction mechanism was elucidated at the molecular level using FT-IR, Raman, NMR, and density functional theory (DFT) calculations. The results demonstrated that the TOP-FeCl 3 -MIBK system achieved an 85 % extraction efficiency for Li + in a single stage, with a Li + /Mg 2+ separation factor reaching 5842, surpassing previously reported data in the literature. 31 P NMR and 7 Li NMR analyses revealed that the TOP and tributyl phosphate (TBP) complexes existed in different forms within the organic phase. Slope analysis indicated that the stoichiometric ratio of the extraction complex involving Li + , TOP, and MIBK was LiFeCl 4 ·TOP·MIBK. Furthermore, DFT calculations indicated that the TOP complex was more stable than the TBP complex after extraction. We anticipate that our findings will pave the way for the development of a series of novel extractants with higher Li/Mg selectivity by enhancing steric hindrance and incorporating longer alkyl chains to minimize dissolution loss. We expect this research to inspire the development of similar neutral organophosphorus extractants.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Jingjing Zhang,Yang Feng,Lixia Ling,Caiping Ma,Jungang Wang,Riguang Zhang,Maohong Fan,Bo Hou,Debao Li,Baojun Wang
The direct conversion of syngas to ethanol faces challenges due to catalyst inefficiencies and low ethanol yield. Bulk alloys with an appropriate atomic ratio can exhibit excellent catalytic performance. In this work, a series of Rh x Ni y (111) with different Rh/Ni ratios was rationally designed, and the ethanol preparation from syngas was explored based on density functional theory (DFT) calculation and microkinetic analysis. The results show that Rh 1 Ni 1 (111) was screened out to show optimum catalytic performance for ethanol production. This was attributed to a moderate quantity of charge transfer from Ni to Rh atoms, and a medium distance from the d -band center to the Fermi level. Further, to verify the catalytic performance of the catalysts at a Rh: Ni ratio of 1: 1, 1Rh1Ni/γ-Al 2 O 3 catalyst was prepared and its catalytic performance for ethanol preparation from syngas was investigated by comparing it with that of Rh/γ-Al 2 O 3 and Ni/γ-Al 2 O 3 . The catalytic performance of 1Rh1Ni/γ-Al 2 O 3 has been further confirmed to be preferred over Rh/γ-Al 2 O 3 and Ni/γ-Al 2 O 3 , achieving a 23.0 % CO conversion rate with 31.2 % ethanol selectivity.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 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）