ATMOSPHERIC ENVIRONMENT
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2024
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IF 4.2
Cici Fan,Huijie Yan,Weigang Wang,Zheng Sun,Maofa Ge
Aldehydes are one of the most important oxygenated volatile organic compounds in the atmosphere, contributing to atmospheric radicals such as HO 2 and RO 2 , which play a pivotal role in atmospheric chemistry and the oxidative capacity of the atmosphere. The kinetics, gas-phase products, and SOA formation of pentanal and n-hexanal initiated by Br atoms were studied in this work. The reaction rate constants of n-pentanal and n-hexanal reacting with Br atoms were determined to be (1.77 ± 0.25) × 10 −11 cm 3 molecule −1 s −1 and (2.07 ± 0.29) × 10 −11 cm 3 molecule −1 s −1 at 298 K and 760 Torr, respectively. Key gas-phase products, including smaller aldehydes, carboxylic acids, and alcohols, are known to contribute to atmospheric reactivity and have potential implications for air quality by promoting the formation of secondary pollutants and influencing the oxidative capacity of the atmosphere. The SOA yields were (5.24 ± 0.10)% and (6.00 ± 1.20)% for n-pentanal and n-hexanal, respectively, higher than the SOA yields of the aldehydes reaction initiated by OH radicals. The higher SOA yields observed from Br atoms oxidation compared to OH radical oxidation highlight the necessity to re-evaluate the role of halogen chemistry in atmospheric processes, particularly in regions where halogen compounds are prevalent. This research enhances our understanding of the atmospheric fate of aldehydes and highlights the importance of considering halogen-driven oxidation pathways in atmospheric models.
研究领域:
环境科学
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大气化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2017
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IF 0
Xiang Li,Kaixuan Zhang,Li Qin,Haihong Ma
The kinetic studies of hydroformylation of 1-butene to produce pentanal were investigated by using Rh/PPh 3 complex as homogeneous catalyst, valeraldehyde and its polycondensates as solvent. The experiment was carried out on small hydroformylation continuous reaction installation. The effects of reaction temperature, the concentration of 1-butene, the partial pressure of CO or H 2 and the concentration of rhodium of catalyst on the reaction rate were studied. Based on the reaction mechanism of hydroformylation and the latest research results of hydroformylation kinetics, the kinetic equation suitable for the hydroformylation of 1-butene was established. The parameters of the kinetic equation were regressed and verified with the experimental data. The relationship between the normal/isomeric ratio of pentanal and the partial pressure of CO was further explored.
研究领域:
化学工程
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催化化学
✓ 已验证
产品关联
DOI
Molecular Catalysis
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2017
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IF 0
Ke Zhao,Shufen Liu,Kexin Li,Ziying Hu,Yukun Yuan,Liushui Yan,Huiqin Guo,Xubiao Luo
Sulfonic acid groups functionalized aromatic carbon microspheres (Ar-CMSs–SO 3 H) were first successfully fabricated directly from waste Camellia oleifera shells by simple steps in the assistance of phloroglucinol . As a heterogeneous solid Brønsted acid catalyst, the as-prepared Ar-CMSs–SO 3 H showed considerably high activity because of its numerous spherical microstructure and abundant surface sulfonic acid groups (–SO 3 H). Subsequently, the as-prepared Ar-CMSs–SO 3 H was applied to the synthesis of biofuels 5-ethoxymethylfurfural (EMF) from biological platform compounds 5-hydroxymethylfurfural (HMF). The catalytic results showed that both sulfonation conditions in the course of Ar-CMSs–SO 3 H preparation and catalytic reaction conditions in the course of EMF synthesis had a significant effect on the EMF yield and HMF conversion rate.
研究领域:
材料科学
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催化化学
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生物燃料合成
✓ 已验证
产品关联
DOI
Molecular Catalysis
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2025
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IF 4.9
Zhibin Xian,Shilin Bo,Xinjun Xu,Hui Wan,Wei Du,Guofeng Guan
Hydroformylation plays a crucial role in the modern chemical industry by enabling the efficient production of aldehydes, which are essential raw materials for a wide range of chemicals. In this study, we reported a pair-site 0.2Rh-0.8WO x /SiO 2 catalyst that demonstrated exceptional performance in isobutene hydroformylation. The catalyst achieved an isovaleraldehyde yield of 89.57 % (TON=8936) after 5 h of reaction at 90 °C and 5 MPa, and retained 85.0 % of its initial yield after four cycles. This performance was significantly superior to that of the catalyst prior to the introduction of W and proved more suitable for the hydroformylation reaction of isobutene compared to previously reported Al 2 O 3 -supported pair-site catalyst. Density functional theory (DFT) calculations revealed that W served as an electronic modulator in the catalytic system. The charge transfer from Rh to W enabled W to adsorb and convert excess CO on the Rh surface, thereby creating vacant active sites for the subsequent insertion of olefin and CO, ultimately enhancing the hydroformylation performance. The pair-site catalyst developed in this study exhibited remarkable improvements in both catalytic activity and stability, offering valuable guidance for catalyst design from an interface science perspective.
研究领域:
催化化学
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化学反应工程
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表面科学
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材料化学
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理论化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD HYDROCOLLOIDS
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2024
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IF 11
Zhong Han,Ze-Ling Chen,Xin-Dong Xu,Songyi Lin,Yan Wang,Lang-Hong Wang,De-Bao Niu,Xin-An Zeng,Meng-Wai Woo,Ruo-Yong Wang
The development of natural polyphenol-protein complexes for preserving surimi holds great promise. The effects of pea protein isolate (PPI) - (−)-Epigallocatechin-gallate (EGCG) non-covalent and covalent complexes modified by pulsed electric field (PEF) on the preservation of tilapia surimi were evaluated. Results showed that the PEF-treated PPI-EGCG non-covalent complex extended the shelf life of surimi by more than 6 days. This complex reduced the microbial activity and delayed the lipid and protein oxidation of surimi during chilled storage. Total viable count (TVC), thiobarbituric acid reactive substances (TBARS), and total volatile base nitrogen (TVB-N) of surimi with PEF-treated PPI-EGCG non-covalent complex on day 15 were 31.65 %, 68.67 %, and 54.46 % lower than untreated surimi, respectively. Moreover, the rate of colour deterioration and off-odour development were also delayed. The major products of lipid oxidation in surimi were reduced by 37.91 % for hexanal , 43.14 % for pentanal, 73.24 % for 1-octen-3-ol, and 39.32 % for 1-penten-3-ol on day 15. Structural analyses and computer simulations revealed that PEF was able to unfold the structure of PPI, thereby exposing more binding sites for EGCG. PEF-treated PPI-EGCG non-covalent complex allowed the slow dissociation of EGCG from PPI and maintained the antimicrobial and antioxidant activities of EGCG in a long storage time. Therefore, PEF-treated PPI-EGCG non-covalent complex was considered as a potential preservative in fish and fish products.
研究领域:
食品科学
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生物技术
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保鲜技术
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
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2019
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IF 3.714
Ping Yang,Chen Liu,Huanlu Song,Lijin Wang,Xueqing Wang,Jiacai Hua
Off-flavor compounds in IF-DHMP were identified using sensory-directed analysis. In total, 56 types of aroma-active compounds were identified in the off-flavor (OF) samples, positive control (PC) samples, and accelerated oxidation (AO) samples. The Aroma Extraction Dilution Analysis (AEDA) results showed that methional, generated via Maillard reaction , was the most important component with the highest dilution factor in OF. The results of aroma recombination, omission and spiking experiment revealed that compounds such as pentanal, methional, ( E )-2-nonenal, 3-methylbutanal, ( E )-2-heptenal, nonanal, ( E,E )-2,4-heptadienal, 1-penten-3-one, 1-octen-3-one, and ( E,E )-2,4-nonadienal were the major sources of off-flavor in OF. We observed that the off-flavor in OF samples originated due to proteolysis, Maillard reaction, or lipid oxidation during processing rather than due to lipid oxidation during storage.
研究领域:
食品科学
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化学感官科学
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分析化学
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婴幼儿营养
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
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2023
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IF 8.8
Yang Yue,Chao Wang,Yashu Chen,Mingming Zheng,Yi Zhang,Qianchun Deng,Qi Zhou
Currently, the effect of varieties on the flavor and stability of flaxseed milk remains unknown. Therefore, this study was conducted to investigate the effects of different varieties on the stability, sensory, and aromas of flaxseed milk. 51 volatile compounds were identified in flaxseed milk using Stir Bar Sorptive Extraction-Gas Chromatography-Olfactometry-Mass Spectrometry (SBSE-GC-O-MS). Among them, 1-octen-3-ol, 2-methoxy-4-vinylphenol, and 2,3,5-trimethylpyrazine contributed higher relative odor active values (ROAV), resulted in the fruity, roasted, sweet, and cucumber in flaxseed milk. Isovaleraldehyde (green notes) was not detected in XHZM. However, other compounds such as 1-nonanol (floral), γ-nonanolactone and γ-octanoic lactone (coconut milk) had higher concentrations, causing a better sensory evaluation. Additionally, its stability was relatively good. The orthogonal partial least-squares regression (OPLS) model and VIP values showed that eight compounds were responsible for the sensory differences from different varietals. The study provided references to selection and understanding flavor composition basis of flaxseed milk.
研究领域:
食品科学
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分析化学
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农学
✓ 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）