Journal of Physical Chemistry C
·
2025
·
IF 3.2
Guang Li,Xiufang Zheng,Xu-Yuan Nie,Rui Huang,Bin-Wei Zhang,Yan-Xia Jiang,Shi-Gang Sun
Identifying the structure–activity relationship of transition metal–nitrogen–carbon (MNC) catalysts during the oxygen reduction reaction (ORR) remains a challenge due to the complexity of active sites and the lack of effective methodologies. In this study, an in situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) CO-probe method is developed to investigate the electronic effects and structural changes of MNC catalysts, using axial-ligand poly(iron phthalocyanine) (PFePc-X2, X = F, Cl, Br, I) model catalysts. These axial ligands modified the electronic structure of the central Fe atoms, leading to the blue–red shift in the in situ ATR-FTIR CO adsorption (COad) wavenumber. By comparing the COad wavenumbers of PFePc-X2 catalysts, the electronic effects of the axial ligand on the active sites were clarified as follows: F > Cl > Br > I. Moreover, structural changes involving the isoindole nitrogen (N), bridge carbon (C), and benzene-ring carbon (C), collectively assigned as the NCC group, indicated that weaker coordinating ligands were more susceptible to desorption during CO adsorption. These results demonstrate that the in situ ATR-FTIR CO-probe method is an effective strategy for investigating ligand effects in MNC catalysts and holds promise as a potential activity descriptor for ORR performance.
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Wenqian Yang,Ziqian Xue,Jun Yang,Jiahui Xian,Qinglin Liu,Yanan Fan,Kai Zheng,Peiqin Liao,Hui Su,Qinghua Liu,Guangqin Li,Cheng-Yong Su
The selective electrochemical reduction of CO 2 to CO is a promising solution for the design of carbon-neutral, sustainable processes. Achieving a highly selective single reduction product is still challenging because of the energetically favorable competing hydrogen evolution reaction. We report the fabrication of N-doped sponge-like porous graphitic carbon structures embedded with Fe nanoparticles (Fe@NPC) via the pre-modification of a metal-organic framework (IRMOF-3(Zn)) with carboxyferrocene, followed by pyrolysis . The as-prepared Fe@NPC exhibited a 96.4% CO Faradaic efficiency at –0.5 V RHE and good stability. The exceptional CO 2 reduction performance is attributed to the unique structure of the composite catalyst, which provides abundant hierarchical pores that increase CO 2 adsorption and mass transfer, and active Fe sites that synergistically accelerate the kinetics of CO generation. The in situ attenuated total reflectance-Fourier transform infrared analysis provided proof of the improved ability of Fe@NPC to accumulate the crucial intermediate *COOH compared with other pyrolyzed porous carbons. Fe@NPC was used in a Zn-CO 2 battery that delivered a maximum power density of 3.0 mW cm –2 , evidencing its potential for application in energy-converting devices.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY A
·
2010
·
IF 2.899
Shengtong Sun,Peiyi Wu
A designed ligand-accelerated Cu(I)-catalyzed cycloaddition (CuAAC) reaction was monitored for the first time by real time infrared analysis technique based on ATR-FTIR principles. Principal components analysis (PCA) and two-dimensional correlation spectroscopy (2Dcos) results showed that the consumption of alkyne and azide took place successively followed by the formation of the product 1,2,3-triazole, and a 1:1 complex of two reactants would be formed in the reaction process. The rate-determining step of the CuAAC reaction was also experimentally confirmed for the first time to be the transition of azide−alkyne 1:1 complex to the preproduct 1,2,3-triazole. Our results are in good conformity with the current catalytic mechanism proposed by Sharpless et al. according to DFT calculation results.
研究领域:
有机化学
·
催化化学
·
光谱学
·
化学反应机理
✓ 已验证
DOI
高影响因子
AAPS PHARMSCITECH
·
2020
·Vol. 21
·期 7
·1-15
·
IF 2.401
Tian Qi,Guo Jianbo,Zhang Qi,Fang Liang,Liu Chao,Xu Hui
The present study aimed to develop a cucurbitacin B microemulsion (CuB-ME) and investigate the mechanism of the enhanced drug skin absorption at the molecular level. Firstly, the pseudo-ternary phase diagrams were developed to evaluate the effect of composition on microemulsion properties systematically. The formulation composition types and ratios of oil phase, surfactant, co-surfactant, and aqueous phase were optimized by an in vitro skin permeation experiment, and the optimized formula was confirmed with the pharmacodynamics study. Furthermore, the molecular mechanism of enhanced skin permeation was investigated using ATR-FTIR and molecular modeling. As a result, the optimized CuB-ME formulation was composed of Azone:Tween 80:ethanol:water = 2.5:16.9:5.6:75.0 ( w / w / w / w ). The oil phase improved skin permeation by disordering the stratum corneum intercellular liquid, while the aqueous phase impacted the particle size of the microemulsion and permeability coefficient of the drug. Besides, the hydration state of skin lipid also enhanced drug permeation by the interaction of water and the polar head of ceramide. The in vitro skin permeation amount was 45.47 ± 10.39 μg/cm 2 , and no significant skin irritation was observed. The pharmacodynamics study demonstrated that CuB-ME had a significant therapeutic effect on the animal tumor model. In conclusion, the CuB-ME was developed successfully and the effect of the oil phase and aqueous phase on drug skin permeation was clarified at the molecular level.
研究领域:
药剂学
·
药学
·
药物递送系统
·
光谱学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
Food Bioscience
·
2025
·
IF 5.9
Walaa Kobacy,Xiaomin Gong,Naglaa K.F. Elshamandy,Hamdy A. Zahran,Ahmed I. Osman,Ahmed K. Rashwan
The study explored the chemical, antimicrobial, and antioxidant properties of essential oils from garlic (GEO), parsley (PEO), and thyme (TEO) using GC-MS, ATR-FTIR, and DSC techniques, and examined the synergistic effects of their combination on antioxidant and antimicrobial properties. The oils' antimicrobial effectiveness against pathogens was also tested. GC-MS analysis revealed diverse chemical profiles. The garlic, thyme, and parsley mixture (GTP) showed the highest phenol content (533.05 milligrams of gallic acid equivalent per 100 grams of dry weight sample), flavonoids (284.16 milligrams of quercetin equivalent per 100 grams of dry weight sample), and antioxidant activity (94.14% DPPH scavenging). The oils demonstrated significant antimicrobial effects, particularly against gram-negative bacteria and molds, with the GTP mixture being highly effective against Aspergillus niger . The bioactive compounds and antimicrobial effects were ranked as GTP > GT > GP > TP > GEO > TEO > PEO. These findings suggest that combining these EOs enhances their bioactivity, positioning them as natural preservatives for food safety and shelf-life extension.
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Fuwei Sun,Tianhu Chen,Ziyang Chu,Peixun Zhai,Haibo Liu,Qiang Wang,Xuehua Zou,Dong Chen
A system of Cu 2+ /calcite/PDS was constructed to degrade sulfadiazine (SDZ). Different from the traditional Cu-mediated activation, a low concentration of Cu 2+ that met drinking water standards (≤ 1 mg/L) transformed into Cu(Ⅱ) solid in the presence of calcite, and then enhanced the degradation of SDZ via PDS activation over a pH range from 3 to 9. According to scavenger and chemical probe experiments, Cu(Ⅲ), rather than radicals (hydroxyl radicals and sulfate radicals) and singlet oxygen, was the predominant reactive species, which was responsible for the degradation of SDZ. Based on the results of XRD, ATR-FTIR, and CV curves et al., CuCO 3 was the main complex with high reactivity for PDS activation to form Cu(Ⅲ). Moreover, detailed degradation pathways of sulfadiazine were proposed according to the UPLC-ESI-MS/MS and their toxicity was predicted by ECOSAR. Besides, the real water matrix would not seriously affect the degradation of SDZ in the Cu 2+ /calcite/PDS system. In summary, this study reveals a new insight into the synergistic effect of Cu 2+ and calcite on the SDZ degradation, and promotes an understanding of the environmental benefits of natural calcite.
研究领域:
环境科学
·
化学工程
·
分析化学
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Lulu Chen,Xiaona Dong,Ruonan Feng,Wanying Li,Dahu Ding,Tianming Cai,Canlan Jiang
Triclosan (TCS) is a compound in pharmaceutical and personal care products (PPCPs) that preferentially accumulates in soil and may threaten human health. Iron-based persulfate activation processes (Fe-PAPs) are a promising technique in soil remediation but are limited by their narrow pH application range and resultant iron precipitation. In this study, oxalic acid (OA) was specifically introduced to improve the efficiency of Fe 2+ -activated persulfate (PS) processes for TCS degradation in soil. The complexation of OA and Fe 2+ improved the total iron concentration in the Fe 2+ /OA/PS system and prevented iron precipitation. Fe-minerals in soil were also dissolved by OA, which participated in PS activation. The most appropriate proportion of Fe 2+ /OA/PS is 1:1:1, and approximately 85% of the TCS was degraded within 240 min compared with 45% in the Fe 2+ /PS system. SO 4 • - and 1 O 2 played important roles on TCS oxidation, while O 2 • - and CO 2 • - mainly participated in the iron cycle. The weak stretch of Fe-O in OA containing treatments in ATR-FTIR measurements provided evidence that OA dissolved the Fe-minerals. The introduction of OA in the Fe 2+ /PS system in four different soils reduced the negative effect of soil organic matter on TCS degradation. Three types of intermediates including hydroxylation, cleavage of ether bonds and cyclization products, were identified by LC-Q-TOF-MS. Column experiments were used to study the feasibility of in situ chemical oxidation (ISCO) remediation of TCS in the Fe 2+ /OA/PS system. Our findings indicated the ability of OA to be used as a cheating agent in Fe-PAPs for TCS soil remediation.
研究领域:
环境科学
·
土壤化学
·
污染物降解
·
修复技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2025
·
IF 6.3
Canyan Yang,Wei Liu,Zhao Zuo,Jinhua Xiao,Huawang Zhao,Bihong Lv,Zuoming Zhou,Xiaomin Wu,Guohua Jing
Carbon-carbon (C-C) coupling, the rate-determining step in electrocatalytic CO 2 reduction reaction (CO 2 RR) to C 2+ products, has low efficiency and poor stability. It originates from an ineffective water dissociation capability and a high energy barrier for the C-C coupling pathway on existing catalysts. Herein, an efficient and facile Br-CuO electrocatalyst was synthesized to promote water dissociation and achieve an impressive Faradic Efficiency (FE) of around 60% C 2 H 4 at a current density of up to -350 mA/cm 2 with stability of 16 h. Combinative theoretical and experimental protocols strongly evidence that the architecture of Cu 0 -Cu + sites is crucial for the enhancement in CO 2 RR activity. Cu 0 activates CO 2 and Cu + strengthens *CO adsorption to further boost C-C coupling. Furthermore, Br doping can facilitate the dissociation of water to generate *H, which promotes the protonation of *CO to *CHO, thereby enabling the low energy barrier asymmetric *CHO-*CO coupling. The in situ ATR-FTIR and Density functional theory (DFT) was analyzed to explain the reaction mechanism and pathway. This study elucidates the critical function of water dissociation and provides a promising avenue to efficient CO 2 -to-C 2 H 4 electrocatalysis.
研究领域:
电化学
·
催化
·
材料科学
·
能量转换
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2019
·
IF 3.714
Ying Ji,Xun Lin,Jicheng Yu
This study developed oxidized starch-chitosan complexes for the adsorption of procyanidins . Oxidized starch-chitosan complexes were prepared in two steps. Native cornstarch was first oxidized with a 2,2,6,6-tetramethyl piperidinyloxy (TEMPO) mediated reaction and then surface coated with chitosan to adsorb procyanidins. This study evaluated the morphologies and structures of starches in addition to the adsorption properties of procyanidins onto oxidized starch-chitosan complexes. The zeta potential revealed that the optimal weight ratio of oxidized starch and chitosan in the complexes was 1:0.4. The UV–visible spectrum of the complexes showed absorption spectra at about 255 nm, which has never been observed for oxidized starch. X-ray analysis and SEM indicated that the complexes changed the crystallinity and morphology of native starch. The ATR-FTIR spectra suggested that electrostatic interactions may be present between the -COO - of oxidized starch and –NH 3 + of chitosan. The adsorb experiments suggested that the oxidized starch-chitosan complexes could potentially be applied as carriers of bioactive compounds . This paper provides a good reference for an efficient adsorbent of polyphenols by oxidized starch-chitosan complexes.
研究领域:
材料科学
·
食品科学
·
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2017
·
IF 3.648
Ai-Rong Xu,Shuan Wen,Lin Chen
Novel cellulose solvents, MIM-[N 4444 ][CH 3 CH 2 COO], were developed by coupling N -methylimidazole (MIM) with tetrabutyl ammonium propionate ([N 4444 ][CH 3 CH 2 COO]). The solubilities of cellulose in MIM-[N 4444 ][CH 3 CH 2 COO] solvents were determined at 25 °C. The effect of MIM content on cellulose solubility and the possible dissolution mechanism of cellulose in MIM-[N 4444 ][CH 3 CH 2 COO] solvent have been investigated. It was found that [CH 3 CH 2 COO] − anion in MIM-[N 4444 ][CH 3 CH 2 COO] solvent is the main driving force of the cellulose dissolution by interacting with the hydroxyl hydrogen atom in cellulose, and the role of MIM is mainly to disassociate/dilute [N 4444 ][CH 3 CH 2 COO]. In addition, the morphology and structure of the regenerated cellulose materials from MIM-[N 4444 ][CH 3 CH 2 COO] solvent were characterized by scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD).
研究领域:
材料科学
·
化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 9
·919-929
·
IF 2.804
Yang Shi-Xuan,Fan Zi-Yu,Zhang Feng-Yu,Li Si-Hao,Wu Yi-Xian
The random copolymers of isobutylene (IB) with polar comonomers of 4-acetoxystyrene (ACS) or 4- tert -butoxystyrene (TBO), P(IB- co -ACS) and P(IB- co -TBO), could be successfully synthesized via cationic copolymerization with FeCl 3 -based initiating system. The kinetics of the cationic copolymerization process was in situ investigated by inserting a diamond probe into the reaction system by ATR-FTIR spectroscopy. The chemical structure and incorporation content of polar comonomers in the copolymers were characterized by GPC with RI/UV dual detectors and 1 H-NMR spectroscopy. The corresponding functionalized random copolymers of IB with vinyl phenol P(IB- co -POH) carrying phenolic hydroxyl side groups could be further prepared via the complete hydrolysis of acetoxyl side groups in P(IB- co -ACS) or tert -butoxyl side groups in P(IB- co -TBO) copolymers. The functionalized P(IB- co -POH) copolymers became hydrophilic with water contact angle (WCA) of ca . 80° for the self-assembly in hot water, compared to the hydrophobic polyisobutylene with WCA of ca . 110°. The functionalized P(IB- co -POH) copolymers also displayed an excellent self-healing property due to the interaction of intermolecular hydrogen bonding and formation of three dimentional supramolecular networks from phenolic hydroxyl side groups. Furthermore, P(IB- co -POH) copolymers also provided a good matrix for the homogeneous dispersion for silica nanoparticles due to the formation of hydrogen bonding between copolymer chains and silica nanoparticles.
研究领域:
高分子化学
·
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Food Bioscience
·
2020
·
IF 3.067
Xiao Guan,Lv Li,Sen Li,Jing Liu,Kai Huang
Hordein electrospun ultra-thin fibers are unstable in an aqueous environment. Chitosan was added to improve their water resistance. With increasing chitosan concentration, the viscosity and conductivity of the biopolymer blends increased, and the surface tensions remained almost constant. The structure and morphology of composite biopolymer fiber membranes showed that the average fiber diameter varied with chitosan concentration. ATR-FTIR spectra showed that the C–H stretching band changed or disappeared with increased chitosan. X-ray diffraction showed that chitosan was distributed in hordein fibers without crystallites. Compared with the hordein nanofibers, thermogravimetric analysis and derivative thermogravimetry curves showed that hordein/chitosan electrospun fibers had slightly decreased thermal stability . In conclusion, a low chitosan content improved the water resistance and other properties of hordein fibers, without changing their morphology or structure.
研究领域:
材料科学
·
食品科学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）