INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Ying’hua Xu,Hai’feng Li,Cheng’pu Chu,Ping Huang,Chun’an Ma
A carbon felt was used as the cathode material for the indirect electrochemical reduction of indigo in alkaline aqueous solution employing iron-triethanolamine (Fe-TEA) complex as a redox mediator. Surface structure and specific surface area of the carbon felt electrode and its electrochemical performance toward the reduction of indigo were investigated by SEM, BET, and cyclic voltammetry, respectively. Moreover, an optimization of different operating conditions for the reduction of indigo was performed with an H-cell. In particular, the dependence of current efficiency (CE) on electrolysis time was chosen to analyze the indirect electrochemical reduction mechanism of indigo. The results showed that the carbon felt, having a high specific surface area of approximately 7289 cm2·g–1, is an excellent electrode material for the indirect electrochemical reduction of indigo and that a moderate current density, temperature, and concentration of indigo has the most beneficial effects on the reduction process.
研究领域:
环境科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2013
·Vol. 17
·期 11
·2789-2794
·
IF 2.279
Lv Weixin,Zhang Rui,Gao Pengran,Gong Chunxia,Lei Lixu
The electrochemical reduction of carbon dioxide (CO 2 ) is investigated in acetonitrile with tetrabutylammonium perchlorate as an electrolyte using a lead cathode and a sacrificial zinc anode, and the product under such a setup is insoluble zinc oxalate at potentials between −2.2 and −2.8 V vs. Ag rod electrode. Preelectrolysis is an effective method to remove the water in the electrolyte, which makes a distinct reduction peak of CO 2 appear at −2.6 V vs. Ag on cyclic voltammogram. Even trace amounts of water in the electrolyte can interfere with the faradaic efficiency of reduction of CO 2 to oxalate, and the product could be β-ZnC 2 O 4 (in anhydrous solution) or ZnC 2 O 4 · 2H 2 O (if water exists). The faradaic efficiency for oxalate production also depends on the cathode potential and the temperature, and the maximum is 96.8 % at −2.6 V vs. Ag and 5 °C. This is the highest value of CO 2 electrochemical reduction found in the literature under ambient pressure.
研究领域:
电化学
·
环境科学
·
材料科学
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能源化学
·
物理化学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2024
·
IF 4.3
Yonghui Yang,Hengwei Yan,Pengchen Yang,Zhanwei Liu,Guang Yang
The segregation of aluminum-silicon alloys directly impacts the mechanical and chemical properties of the alloys, Therefore, homogenization of alloys is of great significance for alloys. This study initially investigated the electrochemical behavior of aluminum (III) and silicon (IV) during the preparation of aluminum-silicon (Al-Si) alloys in NaF-AlF 3 -Al 2 O 3 -SiO 2 molten salts through cyclic voltammetry and steady-state polarization. The results revealed that Al 2 O 3 underwent one-step reduction to Al, whereas SiO 2 underwent a two-step reduction process to Si. In addition, electrolysis experiments were carried out in a NaF-AlF 3 -Al 2 O 3 -SiO 2 -5wt%CaF 2 -1wt%MgF 2 -2wt%LiF molten salt system with molecular ratio of 2.4. These experiments involved variations in current density, electrolysis time, Al 2 O 3 and SiO 2 additions. It is worth noting that under the conditions of current density of 0.7 A/cm 2 , electrolysis time of 2 h, and silica addition of 2 %, the reduction rate of silicon reached a maximum value of 72.57 %, at which time the silicon in the aluminum-silicon alloys showed a dendritic structure, which was uniformly distributed throughout the entire alloy, and the segregation of the alloy was effectively avoided.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Haitao Zhang,Ningchen Ye,Runzhe Dong,Qing Li,Zheng Wang,Zifei Gao,Xiang Ji,Lin Liu,Juanjuan Ma,Zhiwei Tong
A simple electrochemical reduction technique was employed to generate Ti 3+ with strong reducing property on the anodic TiO 2 nanotubes (ATNTs). Utilizing Ti 3+ as the reducing agent, Pd 2+ was successfully reduced in situ to Pd 0 on the anodic TiO 2 nanotubes (Pd@ATNTs). Various characterization methods were employed to confirm that the proportion of Ti 3+ and the size of Pd nanoparticles could be controlled by adjusting the electrochemical reduction voltage. The obtained [email protected] exhibited satisfactory catalytic efficiency (TOF: 1302 h −1 ) in the Heck reaction between various aryl halides and olefins. Furthermore, [email protected] demonstrated high stability, with no significant loss of catalytic activity observed even after six cycles.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Zezhong Cao,Panpan Su,Xinyao Wang,Xiaoyan Liu,Yanfu Ma,Congming Li,San Ping Jiang,Jian Liu
Single-site metal catalysts (SSMCs) with high activity and stability have been widely applied as electrocatalysts for electrochemical CO 2 reduction reaction (CO 2 RR) process. However, it remains challenging for precise controlling the nanoarchitectures and atomic metal sites of SSMCs to investigate their corresponding structural and related catalytic properties toward CO 2 RR. In this work, four categories of Ni based SSMCs with different nanoarchitectures were successfully synthesized, including Ni-N doped solid carbon spheres with micropore (Ni-N/C-S-Micro), Ni-N doped hollow carbon spheres with micropore (Ni-N/C–H-Micro), Ni-N doped hollow carbon spheres with mesopore (Ni-N/C–H-Meso), and Ni-N doped hollow carbon spheres with micropore and mesopore (Ni-N/C–H-Micro/Meso). Ni-N/C-S-Micro and Ni-N/C–H-Micro were favorable for the generation of atomic Ni sites in SSMCs, resulting in higher loading amount of Ni, while Ni-N/C–H-Meso with open structure leads to the aggregation of Ni species during pyrolysis. In comparison with Ni-N/C-S-Micro, carbon spheres with hollow and mesoporous structures can enhance the diffusion of CO 2 and improve the catalytic activity of per Ni site toward CO 2 RR process. Thus, Ni-N/C–H-Meso shows the highest turnover frequencies (TOF) value for CO 2 RR to CO. This study provides a SSMCs design protocol for investigation the SSMCs correlation of structure and properties toward electrochemical conversions.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2021
·Vol. 8
·期 10
·2461-2467
·
IF 6.569
Yingchun Zhang,Changsheng Cao,Xin-Tao Wu,Qi-Long Zhu
Bismuth (Bi)-based nanomaterials are considered as promising electrocatalysts for the electrocatalytic CO2 reduction reaction (CO2RR), but it is still challenging to achieve high current density and selectivity in a wide potential window. Herein, Cu-decorated Bi/Bi2O3 nanofoam (P–Cu–BiNF) with a 3D porous network structure was prepared for the first time via a simple fast-reduction method. Characterizations indicate that the introduction of Cu can significantly regulate the microstructure and electronic states of Bi/Bi2O3. Consequently, the as-prepared P–Cu–BiNF exhibits excellent electrocatalytic performance toward the CO2RR. Remarkably, the faradaic efficiency of formate production can exceed 90% in a wide potential range from −0.78 to −1.08 V. Meanwhile, it can also deliver a high formate partial current density of up to 62.7 mA cm−2 at −1.18 V and long-term stability. This work provides a simple but effective way to synthesize advanced Bi-based materials with significantly improved electrocatalytic CO2RR performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Fan Wang,Wei Liu,Yongsong Ma,Di Chen,Peng Li,Huayi Yin,Wei Li,Dihua Wang
Silicon nanotubes (SNTs) are very attractive in the fields of energy, catalysis, and sensors, but a facile template- and/or catalyst-free preparation method is still absent. Herein, we study a controllable and cost-effective approach for preparing SNTs by electrochemically reducing layer-structured calcium silicate (CaSiO3) in molten CaCl2/NaCl without any template and catalyst. The underlying mechanism of the SNT formation is uncovered: the layer-structured CaSiO3 is first electrochemically exfoliated into SiOx (0 < x < 2) sheets while releasing CaO into the molten salts, and then the SiOx sheets are electrochemically reduced and simultaneously crimped into SNTs. The diameter (120–312 nm) and wall thickness (∼40 nm) of the SNTs can be tailorable by manipulating the reduction potential between −1.28 and −1.48 V (vs Ag/AgCl). Lastly, the electrolytic SNTs show a high lithium storage capacity of 3737 mAh g–1 at 0.2 A g–1, a high rate capability of 1371 mA h g–1 at 10 A g–1, and stable cycling with a capacity of 974 mAh g–1 after 600 cycles at 1 A g–1. Overall, the template- and catalyst-free electrochemical method provides a straightforward and facile way to prepare SNTs with a brand-new mechanism that can be applied to other tubular structure materials.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Bioresources and Bioprocessing
·
2015
·Vol. 2
·期 1
·1-9
·
IF 0
Huang Xiaomei,Cao Xuejun
Background Ursodeoxycholic acid (UDCA) is an important clinical drug in the treatment of liver disease. In previous work, ursodeoxycholic acid was prepared by traditional organic synthesis. The preparation of ursodeoxycholic acid through an electrochemical method with higher stereoselectivity and environmental friendliness is described herein. Results Dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and N -methyl-2-pyrrolidone (NMP) were used as stereoselectivity additives during electroreduction. With 107.5 mM DMSO in methanol containing potassium bromide and a continuous current of 20 mA, 936 Coulombs was passed into the electrolysis system, achieving 88.5 % conversion of 7-ketone lithocholic acid (7K-LCA), while the yield of UDCA reached 72.8 %. Cyclic voltammetry (CV) was used to explore the electrochemical behavior of the reaction, and the electrolysis results were consistent with the cyclic voltammograms. Conclusions Ursodeoxycholic acid can be prepared by electroreduction with high stereoselectivity. The method developed here offers a potential application for large-scale production of ursodeoxycholic acid and an interesting reference to asymmetric electrochemical reduction of the keto group.
研究领域:
药学
·
有机化学
✓ 已验证
产品关联
DOI
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Xueye Wang,Zhiwei Wang,Haiqin Chen,Zhichao Wu
Efficient removal of toxic metals using low-pressure membrane processes from contaminated waters is an important but challenging task. In the present work, a conducting microfiltration membrane prepared by embedding a stainless steel mesh in the active layer of a polyvinylidene fluoride membrane is developed to remove Cu(II) ions from contaminated waters. Results showed that the conducting membrane had favorable electrochemical properties and stability as cathode. Batch tests showed that Cu(II) removal efficiency increased with the increase of voltages and leveled off with the further enhancement of electric field. The optimal voltages were determined to be 1.0 V and 2.0 V for the influent Cu(II) concentrations of 5 mg/L and 30 mg/L, respectively. X-ray photoelectron spectroscopy and X-ray diffraction results demonstrated the presence of Cu(0) and Cu(OH) 2 on the membrane surface. The removal mechanisms involved the intrinsic adsorption of membrane, electrosorption of membrane, adsorption of deposited layer, chemical precipitation of Cu(OH) 2 and deposition of Cu(0) which were aided by electrophoresis and electrochemical oxidation-reduction. Long-term tests showed that the major contributors for Cu(II) removal were the deposition of Cu(0) by electrochemical reduction-oxidation (47.3% ± 8.5%) and chemical precipitation (41.1% ± 0.2%), followed by electrosorption, adsorption by the fouling layer and membrane intrinsic sorption.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yi Li,Yanghan Chen,Tao Chen,Guoqiang Shi,Lin Zhu,Ye Sun,Miao Yu
Ethanol (C2H5OH) is an economically ideal C2 product in electrochemical CO2 reduction. However, the CO2-to-C2H5OH conversion yield has been rather low and the underlying catalytic mechanism remains vague or unexplored in most cases. Herein, by decorating small Cu2S nanocrystals uniform ly on Cu nanosheets, three desirable features are integrated into the electrocatalyst, including a relatively high positive local charge on Cu (Cuδ+), abundant interfaces between Cuδ+ and zero-valence Cu0, and a non-flat, stepped catalyst surface, leading to the promoted affinity of *CO, decreased *COCO formation barrier, and thermodynamically preferred *CH2CHO-to-*CH3CHO conversion. As a result, a high partial current density of ∼20.7 mA cm–2 and a Faraday efficiency of 46% for C2H5OH are delivered at −1.2 V vs reversible hydrogen electrode in an H-cell containing a 0.1 M KHCO3 solution. This work proposes an efficient strategy for the high-yield CO2-to-C2H5OH conversion, emphasizing the promise for the industrial production of alcohol and related products from CO2.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Hui Gao,Gong Zhang,Dongfang Cheng,Yongtao Wang,Jing Zhao,Xiaozhi Li,Xiaowei Du,Zhi-Jian Zhao,Tuo Wang,Peng Zhang,Jinlong Gong
Electrochemical CO 2 reduction is a sustainable method for producing multicarbon alcohols. However, the selectivity of alcohols is limited owing to the favorable side reaction to convert the key intermediate of *CH 2 CHO into ethylene. This study describes the design of a Cu electrocatalyst with abundant step sites to suppress the deoxygenation of *CH 2 CHO to ethylene, thereby promoting alcohol production. A Faradic efficiency of 40.5% and partial current density of 56.3 mA/cm 2 for alcohols are achieved. Moreover, the alcohols/C 2 H 4 ratio in the products reaches approximately 2.2. In-situ infrared spectrum characterizations and theoretical calculations reveal that the step sites facilitate C–C coupling and direct the reaction pathway to promote the formation of alcohols by inhibiting the cleavage of the C–O bond in *CH 2 CHO. Therefore, the proposed strategy is efficient for designing active sites to steer reaction pathways in CO 2 electroreductions and produce alcohols.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2023
·
IF 3.6
Yapeng Kong,Yu Xiao,Xuemin Liang,Yangyang Fan,Liqiang Wang,Sheng Yang,Jilin He,Yuran Chen
We report a facile approach for the synthesis of nanoscale tantalum powder through the electro-deoxidation of Ta 2 O 5 cathode in molten Na 3 AlF 6 -K 3 AlF 6 -AlF 3 . The cathodic process begins with a solid-liquid reaction between Ta 2 O 5 and the electrolyte, resulting in the formation of M x TaO 2+ x F 1- x (M = Na, K) intermediates, which are then electrochemically reduced to tantalum directly. We developed a Ta 2 O 5 cathode with a new porous structure, which contains interconnected microporous, mesoporous and macroporous structures, possessing properties such as high surface area, high pore volume ratios, and excellent accessibility to active sites. This novel cathodic pore structure material enabled the formation of uniform-sized M x TaO 2+ x F 1- x particles with a regular cubic morphology by providing abundant nucleation sites and promoting uniform growth of intermediate. The electrochemical decomposition of these particles and the nucleation, growth mechanisms of tantalum product were also investigated. Our study demonstrates the rational design and synthesis of hierarchically porous cathode materials can facilitate the controllable synthesis of nanoscale metal powders by the FFC process, and may open up new opportunities for the development of other materials with desired morphology and particle size.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）