AICHE JOURNAL
·
2025
·
IF 4
Hui Wang,Yifan Jin,Yaxin Jin,Siyu Kuang,Tianxiang Yan,Xinyue Wang,Xiao Wang,Wenquan Cui,Sheng Zhang
Electrochemical carbon dioxide reduction reaction (CO 2 RR) is one of the most prospective strategies to achieve carbon neutrality. Multi-carbon compound (C 2+ ) products have higher commercial value and wider applications, among which ethanol is a widely used chemical feedstock and high energy density fuel. Here, we prepared nitrogen-doped carbon nanofibers containing copper-zinc double atoms using the electrospinning technique and controlled the content of both metal atoms by varying the calcination temperature. This catalyst exhibited ultra-high selectivity for ethanol at low potentials. Ethanol selectivity at −0.3 V versus RHE was more than 60% with the total alcohol selectivity of over 80%. Meanwhile, we explored the ethanol production pathway by combining density-functional theory (DFT) and ATR-FTIR spectroscopy, and found that OCCO* intermediates were most abundant for the optimal ratio of Cu to Zn atoms, lowering the energetic barriers to ethanol formation, and thus improving the selectivity of ethanol production.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2021
·Vol. 39
·期 8
·975-983
·
IF 3.603
Li Hui-Xian,Hou Lei,Wu Pei-Yi
The time-resolved attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is employed to investigate the transport mechanism of gel electrolytes by monitoring the diffusion behavior of propylene carbonate-lithium bis(trifluoromethylsulfonyl)imide (PC-LiTFSI) solution through poly(vinylidene fluoride- co -hexafluoropropylene) (P(VDF-HFP)) films. Fickian behavior has been observed for both TFSI − and PC. Higher temperature leads to faster diffusion of TFSI − and PC, which could be related to the increased free volume in P(VDF-HFP) matrix and rapid molecular movements upon heating. Various molecular interactions among LiTFSI, PC and P(VDF-HFP) have been recognized. During the diffusion process, PC molecules, in the form of small clusters, can firstly diffuse through the P(VDF-HFP) film and interact with P(VDF-HFP) by dipole-dipole interaction, acting as the plasticizer. Then, Li + diffuses into P(VDF-HFP) with the help of ion-dipole interactions between Li + and C-O of PC. Meanwhile, TFSI − diffuses through the polymer matrix in solvation states. In addition, slight ion-dipole interactions between Li + and P(VDF-HFP) have been observed as well. Results in this work contribute to a better understanding of transport process in gel polymer electrolytes for lithium-ion batteries and support the development of improved gel polymer electrolytes by rationally regulating molecular interactions.
研究领域:
高分子化学
·
电化学
·
能源材料
·
锂离子电池
·
光谱分析
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2020
·
IF 2.463
Li Yang,Le Yang,Suqin Sun,Qun Zhou,Ling Dong,Jianbo Chen
Rhubarb has a long history of medicinal applications in Asia and Europe. For some clinical applications of traditional Chinese medicine, rhubarb has to be stir-baked to scorch to eliminate the purgative activity, but increase the functions of blood-cooling and hemostasis. Understanding the chemical transitions during the stir-baking process is necessary for the quality assessment a quality control of scorched rhubarb. This research used the heated ATR-FTIR spectroscopy to study the thermal transitions of rhubarb and related compounds. Critical points during the heating process of rhubarb, emodin, emodin-8-glucoside, glucose and 5-HMF were recognized from PCA score plots. Two-dimensional correlation spectroscopy (2DCOS) was used to interpret the spectral changes of rhubarb during different thermal stages. It was found that the decomposition of anthraquinone glycosides and the formation of aromatic carbon networks at high temperature (above 170 °C) may be the primary reactions to generate scorched rhubarb. These results are helpful for the reasonable procedure optimization and quality control of the stir-baking process to produce scorched rhubarb.
研究领域:
药学
·
分析化学
·
中医
✓ 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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Huanzheng Yang,Xiaoting Huang,Zhihang Liu,Xu Lin,Qiuyan Chen,Jiawang Li,Chenyue Zhang,Zhi Peng Kan,Zhi Qun Tian,Pei Kang Shen
Ammonia has been emerging as a sustainable and environmentally friendly fuel. However, direct electrochemical ammonia oxidation reaction (AOR) in low-temperature fuel cells seriously suffers from high overpotential and deficient durability. Herein, rhombic dodecahedron nanoframe of platinum iridium copper (PtIrCu) with high-index faceted hyperbranched nanodendrites (RDNF-HNDs) was developed using a one-step self-etching solvothermal method . The framework structure with the high-index facets enables the PtIrCu nanocrystals to expose more effective active sites. They exhibit an ultra-low onset potential of 0.33 V vs. RHE and high mass activity of 26.1 A g PtIr –1 at 0.50 V, which is 140 mV lower and 7.5 times higher than that of commercial Pt/C in the AOR. In situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy verifies that AOR on PtIrCu RDNF-HNDs prefers to the NH x dimerization pathways, effectively alleviating the poison of N ads and NO x . The theoretical calculation also shows that both introducing Cu atoms into PtIr alloy and increasing the content of Ir in PtIrCu alloy can reduce the reaction energy barrier of electrochemical dehydrogenation from *NH 2 to *NH. The specific structure of PtIrCu RDNF-NDs provides a new inspiration to solve the critical issue of electrocatalysts for AOR with low activity and durability.
研究领域:
材料科学
·
电化学
·
纳米技术
·
催化
✓ 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）