INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Shanshan Wu,Meng Tian,Yang Hu,Nan Zhang,Wei Shen,Jianyi Li,Linchuan Guo,Pengfei Da,Pinxian Xi,Chun-Hua Yan
Formate is identified as economically viable chemical fuel from electrochemical carbon dioxide reduction. However, the selectivity of current catalysts toward formate is limited by the competitive reaction such as HER. Herein, we propose a CeO2 modification strategy to improve the selectivity of catalysts for formate through tuning of the *OCHO intermediate, which is important for formate production.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2016
·
IF 4.12
Erwei Leng,Yang Wang,Xun Gong,Biao Zhang,Yang Zhang,Minghou Xu
The influence of KCl and CaCl 2 on the primary reactions of cellulose pyrolysis is studied using a wire-mesh reactor from 250 °C to 600 °C, focusing on the reaction intermediates. A pre- column derivatization with benzoyl chloride prior to HPLC analysis is applied for the quantification of anhydro-sugars (levoglucosan, cellobiosan, maltosan) from pyrolysis. At low temperatures, the additions of inorganics salts, especially CaCl 2 , weakens hydrogen bonds, resulting in high yields of levoglucosan and cellobiosan from the cleavage of glycosidic bonds rather than from dehydration reactions . At elevated temperatures, dehydration reactions in the sugar units are mainly responsible for the destruction of sugar rings followed by the scission of pyran rings, leading to the weight-loss of CaCl 2 -loaded cellulose in the form of low molecular weight organic species. Meanwhile, accumulated unsaturated structures suppress the cleavage of glycosidic bonds, leading to the formation of char. However, KCl appears to catalyze the cleavage of glycosidic bonds or the scission of pyran rings directly, which perhaps occurs through a homolytic mechanism, leading to low molecular weight species. Furthermore, maltosan is shown to be a secondary product and is catalyzed by KCl and CaCl 2 indirectly through the repolymerization of levoglucosan in the solid phase. A modified mechanism is also proposed regarding cellulose pyrolysis and the primary catalysis of KCl and CaCl 2 .
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2018
·
IF 1.666
Shizong Wang,Jianlong Wang
Triclosan is an extensively applied antimicrobial agent which has been frequently detected in the environment. In this paper, the degradation of triclosan and its main intermediates was investigated during the combined irradiation and biological treatment. The results showed that triclosan degradation increased with increase of absorbed dose, the removal efficiency of triclosan was 62%, 77%, 87%, 91% and 94%, respectively at 1, 2, 3, 4 and 5 kGy. The final removal efficiency of triclosan after the combined irradiation and biological process was 81%, 86%, 90%, 92% and 95%, respectively. During the irradiation process, two main intermediates, that is, 4,4′-2′-phenoxyphenol (Intermediate 1) and 4-chloro-2′-phenoxyphenol (Intermediate 2) were detected, in which Intermediate 1 dominated during the irradiation process. In the following biological treatment process, Intermediates 1 and 2 could be further degraded. In single biological treatment process, the final removal efficiency of triclosan was 54%, and Intermediates 1 and 2 were detected. Intermediate 1 could be biodegraded while Intermediate 2 could not. The concentration of Intermediate 2 increased during biological treatment process. In conclusion, irradiation as pre-treatment process can enhance the degradation of triclosan and improve the biodegradability of Intermediate 2. Combined irradiation and biological process can be promising for treating antibiotic-containing wastewater.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 10
·期 2
·440-449
·
IF 5.726
Pengqi Zhu,Jin Zhang,Jie Wang,Peng Kong,Yunwei Wang,Zhanfeng Zheng
Hydroxyl coordinated ruthenium dispersed on the surface of γ-Al2O3 can be applied to the selective oxidation of amines with light irradiation and an atmospheric pressure of O2 at room temperature. Sunlight is also an effective light source for the selective aerobic oxidation of primary amines to corresponding nitriles. The high photocatalytic activity and selectivity over Ru/γ-Al2O3 originate from the adsorption of amines and imine intermediates on the abundant surface OH groups of the photocatalyst and further formation of Ru–amide species by ligand exchange of adsorbed amines and imine intermediates with adjacent exposed active Ru sites. Light is introduced to the system successfully via the formation of Ru–amide species, which are used as the light absorption sites of the photocatalytic selective oxidation of amines. Primary amines are directly converted to corresponding nitriles via a two-step oxidative dehydrogenation process.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Baoling Niu,Junzhuo Cai,Wenjing Song,Guohua Zhao
Selective removal of atrazine (ATZ) in wastewater and clarification of the degradation intermediate-toxicity correlation are of great importance. A newly molecularly imprinted, {001} facets-exposed TiO 2 (MI-TiO 2,001 ) photoanode with strong catalytic and selective ability was designed. ATZ was selectively removed from pesticide wastewater, reaching 1.9 µg L −1 , approximately 1/10 of the concentration achieved with nonselective treatment. This selective removal originated from the preferential adsorption and enrichment of ATZ onto MI-TiO 2,001 . The highly specific recognition relied on the halogen bond and strong hydrogen bond formed between the Cl atom and triazine ring π orbital of ATZ and the surface -OH group of MI-TiO 2,001 as well as the recognition of MI-TiO 2,001 to the shape and size of ATZ. The specific interaction leads to different accumulations of intermediates. The correlation of intermediate and toxicity was also discussed. Aquatic toxicity was rapidly reduced through the direct dealkylation path, and due to the accumulation of highly toxic 2‑hydroxy-4-ethylamino-6-isopropylamino-s-triazine, there will be transient fluctuations via the dechlorination-hydroxylation path first. The final product was identified as nearly nontoxic cyanuric acid, the selective accumulation of which indicated that there was almost 100% removal of aquatic toxicity and cytotoxicity with only 9.8% removal of total organic carbon. This work provides new insight into the correlation of pollutant degradation intermediates and changes in toxicity.
研究领域:
环境科学
·
化学工程
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shilun Wang,Wei Peng,Heliang Ma,Xingdi Pan,Yao Shen,Jingkai Zhao,Jiexu Ye,Qiaoli Wang,Pengfei Xie,Shihan Zhang,Xiang Gao
The electrocatalytic reduction of carbon dioxide (CO2RR) by copper oxide-based materials is conducive to the formation of high value-added products, but their activities and selectivities remain unsatisfactory. Organic ligand modification is a promising strategy to achieve a high CO2RR activity. Here, the modification of Cu2O with 1-butyl-3-methylimidazolium chloride (Bmim-Cu2O) enhanced the adsorption of reaction intermediates and improved the stability of the catalyst in the CO2RR, which displays a high Faradaic efficiency of ≈85% to C2+ products with a current density as large as ≈352.5 mA cm–2. In situ characterization reveals a stronger *CO signal with bridge configuration and a stronger *OCCHO signal over Bmim-Cu2O than unmodified Cu2O and can improve the stability during electrochemical CO2 reduction. Density functional theory calculations show that local molecular modulation can effectively regulate the electronic structure of Cu2O and enhance the adsorption of *CO and *CHO intermediates through the stabilization of a noncovalent interaction, which can greatly promote the asymmetric *CO–*CHO coupling in the electrochemical reaction process.
研究领域:
电化学
·
催化
·
材料科学
·
环境科学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Jun Zhai,Quanfeng Wang,Qing Li,Bo Shang,Md. Hasibur Rahaman,Jialiang Liang,Jiucui Ji,Wenbo Liu
Carbamazepine (CBZ), a widely used antiepileptic drug, is refractory to biological wastewater treatment . Rapid removal of CBZ is possible using synthetic manganese oxide (δ-MnO 2 ) but the removal mechanisms require further investigation. In this study, CBZ degradation by δ-MnO 2 was carried out at different pH to further explore the degradation mechanisms. Results show that CBZ degradation by δ-MnO 2 was highly pH dependent, and rapid degradation occurred when pH <2.8. Based on the density functional theory calculations, increasing [H + ] not only increased the reactivity of δ-MnO 2 , but also enhanced the secondary reactions of the intermediates. During the degradation process, protonation of CBZ degradation intermediates, instead of CBZ, played an important role. The overall kinetics of CBZ degradation was then described by the retarded first-order model. The initial rate (r init ) in the model between pH 2.0 and 6.2 was determined to be r init = (2.41 ± 0.51) × 10 −3 [CBZ] 1.21 [MnO 2 ] 1.07 [H + ] 1.41 . This is the first report revealing that protonation of intermediates from CBZ degradation can improve the CBZ oxidation by δ-MnO2. The pathways of CBZ degradation by δ-MnO 2 were also proposed. The results of this study provide a new insight into the processing mechanism.
研究领域:
环境科学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
MONATSHEFTE FUR CHEMIE
·
2023
·Vol. 155
·期 1
·99-104
·
IF 1.8
Dong Wenwen,Gong Tengfei,Liu Chaoyang,Lin Jia,Jia Qiang,Chu Changhu
Apixaban is a highly potent, selective, and efficacious inhibitor of blood coagulation factor Xa. A practical and efficient process has been developed for the preparation of the key intermediate of apixaban. Starting from inexpensive 4-chloronitrobenzene and piperidine, an eight-step procedure for the intermediate has been developed. In this case, sodium chlorite is used twice to oxidize the piperidine cycle to the corresponding lactam under a CO 2 atmosphere, resulting in the construction of two lactams. Furthermore, most of these reactions are highly efficient and practical as they occur under mild conditions. Most of the intermediates can be obtained through simple slurry or recrystallization, and column chromatography purification is not necessary. Graphical abstract
研究领域:
药物化学
·
有机合成
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Wei Guo,Yao Qin,Cheng Liu,Binbin Guo,Junhua Zou,Zenghong Xie,Ling Wu
This work reports the rapid and effective photocatalytic dechlorination of 3,3′,4,4′-trtrachlorobiphenyl (PCB77) with highly dispersed Pd nanoclusters loaded two-dimensional (2D) TiO 2 (B) nanosheets (Pd/TiO 2 (B)) under visible light irradiation, achieving a dechlorination efficiency of 100 % with H 2 O used as an H-donor source. The ultra-thin TiO 2 (B) nanosheets provide a good platform for studying the dechlorination intermediates/pathways of PCB77 at the molecular level. It is proved that the dechlorination of PCB77 is a stepwise process, in which chlorines at the para positions are much more susceptible than those at the meta positions due to the activation of the C Cl bond in the presence of Pd nanoclusters. Furthermore, in-situ FTIR results of D 2 O absorption suggest that the TiO 2 (B) nanosheets with abundant surface defects greatly promote the activation of water molecules via the formation of surficial complexes by hydrogen bonds. Finally, a synergistic mechanism is proposed for photocatalytic dechlorination of PCB77 over Pd/TiO 2 (B). The study provides an efficient method for complete dechlorination of PCB77 and an in-depth understanding photocatalyzed dechlorination reaction mechanism at the molecular level, which may extend to other photocatalytic dehalogenation reactions of halogenated pollutants.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2022
·Vol. 15
·期 22
·8542
·
IF 3.252
Yue Zhang,Ruixing Li
Nanoscale tungsten bronze can convert near-infrared light into thermal energy. For a chemical synthesis, intermediate products and processes are potentially positive or negative to an end product. In this study, (NH4)2SO4was added into the hydrothermal system of WO3, CsCl, CH3CH2CHO, and NH3·H2O to increase the Cs/W ratio in solution. An intermediate, Cs1.1W1.65O5.5, was isolated. Subsequently, it was confirmed via a kinetics experiment conducted for different times. The results of the NH3·H2O and NH4COOCH3system indicate there are two influence factors that influence the formation of Cs1.1W1.65O5.5: the leaching out of W and imine reactions. A low leaching out rate induces a high Cs/W ratio and low-concentration W in solution, leading to the formation of Cs1.1W1.65O5.5. The imine reaction decreasing CH3CH2CHO restrains the reduction in Cs1.1W1.65O5.5. The increase in CH3CH2COO−with the reduction reaction results in both the micron-size sticks and nano-size equiaxial particles in powder.Keywords:cesium tungsten bronze;intermediate;hydrothermal;synthesis;near-infrared response
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Xianda Li,Zhongping Shao,Haozhe Shan,Li Liu
Cellulose utilization has been seriously hindered by the formation of humins, whereas humins structure remains challenging since unconverted cellulose and humins exist as solid mixture. In this work, we developed a novel strategy to extract humins from unconverted cellulose and disclosed the structural evolution process of cellulose-derived humins for the first time. The key intermediate of levoglucosan was successfully captured and identified, which significantly favors the formation of anhydro-sugars followed by polymerization due to the stability. By means of comprehensive HPLC-MS/MS, FT-IR, MALDI-TOF and SEM characterizations, it was proposed that multiple elementary reactions were involved in the formation of cellulose-derived humins, including cellulose depolymerization, etherification, esterification, aldol condensation, dehydration and thermal oxidation. In the early stage, cellulose depolymerization results in glucose and levoglucosan (LG), which undertake etherification to form the early humins via small molecule mechanism, accompanied by esterification and dehydration. In the later stage, gluco-oligosaccharides esp. with LG end from cellulose depolymerization undergo etherification via oligomer mechanism. Meanwhile, etherification of HMF and aldol condensation with LA take place prominently, together with dehydration and oxidation, resulting in the enhancement of C=C and C=O conjugation.
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 69
·36875-36881
·
IF 3.708
Fengcong Gong,Shouqin Tian,Baoshun Liu,Dehua Xiong,Xiujian Zhao
Distinct from the popular opinion that only the zinc-blende CuInS2 phase could be prepared in the presence of oleic acid (OA), CuInS2 nanocrystals with different phase structures and shapes were synthesized by a facile heat-up method through simply adjusting the OA dosage. Zinc-blende CuInS2 quantum dots (QDs) with a triangular pyramidal shape were obtained at a low dosage of OA (<1 mL). With an increase in the OA dosage (∼1.5 mL), wurtzite CuInS2 hexagonal nanoplates were formed accompanied by zinc-blende CuInS2 QDs. A higher OA dosage (2–3 mL) led to the production of wurtzite CuInS2 hexagonal nanoplates. The formation of the CuInS2 nanocrystals with tunable structures was mainly attributed to the role of OA dosage in the formation and transformation of a CuIn(SR)x intermediate. A high OA dosage could facilitate the formation and crystallization of the intermediate, giving a metastable wurtzite CuInS2 structure that could be gradually converted into a stable zinc-blende CuInS2 QDs as the reaction proceeded. However, a low OA dosage would lead to low crystallinity of the intermediate, and thus the intermediate was transformed into a stable zinc-blende CuInS2 phase easily. Therefore, our work could provide guidance for the controllable synthesis of other multi-component chalcogenide nanocrystals.
研究领域:
材料科学
·
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）