Results in Physics
·
2019
·
IF 3.042
Baosong Li,Dandan Li,Tianyong Mei,Weiwei Zhang
Ni-W/ZrO 2 -CeO 2 composite coating has been fabricated via pulse electrodeposition. The structure, morphology, composition and the operating parameters of the nanocomposite coating were evaluated and optimized for the enhanced hardness and corrosion resistance. It illustrated that the deposited coatings are dense, crack-free with nodular or granular structure. The average current density of 4–6 A dm −2 , duty cycle of 70% is beneficial to the finer structure and higher content of nanoparticles in deposits. The average roughness, crystallite size and growth rate of the composite coating was examined. The hardness as a function of duty cycle, current density and deposition time were investigated. The optimal parameters for the improved performance of the composites were given. It was illustrated that the reinforcing particle phase had been uniformly co-deposited in the coating. The embedded ZrO 2 and CeO 2 particles could enhance the corrosion resistance and hardness of Ni-W metallic matrix. Ni-W/ZrO 2 -CeO 2 nanocomposite coatings possess higher performance in aggressive environment and exhibit great application values.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yuanxing Ning,Minghui Yao,Yuxing Li,Guangchun Song,Zhiming Liu,Qingping Li,Haiyuan Yao,Wuchang Wang
During the production and transportation of deep-water oil and gas, the low-temperature and high-pressure operating environment might induce hydrate formation and eventual blockage, which poses a serious threat to the flow assurance. Furthermore, the formation, aggregation and deposition characteristics of hydrate would become more complicated in the presence of asphaltene. Consequently, clarifying the effect of asphaltene on hydrate nucleation and growing process plays an important role in the safety production and flow assurance of deep-water oil and gas field. The kinetic characterizations of hydrate nucleation and growth in W/O systems containing asphaltene were investigated via experimental research, molecular dynamics simulations and mathematical modeling. Results revealed that the hydrate nucleation induction time increased with the increase of asphaltene content. The inhibition of hydrate nucleation by asphaltene in high-pressure (5 MPa) experiments was more pronounced than that in low-pressure (3 MPa). On the other hand, asphaltene restrained hydrate formation and the total gas consumption decreased with the increase of asphaltene content. The dynamic adsorption process of asphaltene at oil–water interface and the evolution of the surface coverage with time were elucidated by jointly solving the Ward-Tordai and Langmuir equation. Combined with the above aspects, the induction time model containing asphaltene was developed, which could provide a new perspective and methodology for deep-water flow assurance
研究领域:
石油工程
·
化学工程
·
分子动力学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 19
·9075-9084
·
IF 3.925
Yanping Li,Ya Liu,Li Wang,Hongsheng Lu
Polyacrylamide and its derivatives are widely used in oilfields due to their efficient viscosity building and drag-reducing properties. At present, the commonly used products of polyacrylamide include two types: polymer powder and polymer emulsions. However, the low dissolution rate of powdered products and the instability of polymer emulsions limit their application. Here, we constructed a pH-sensitive inverse polymer emulsion of poly(acrylamide-co-acrylic acid-co-2-acrylamide-2-methylpropyl sulfonic acid), showing a phase separation and phase inversion from W/O to O/W at pH < 6 and pH > 8 due to a pH-switchable surfactant N,N-dimethylcyclohexylamine/Oleic acid complex (DM–OA). The demulsification or phase inversion of the W/O polymer emulsion can release the polymer that was originally in the aqueous phase, and the released polymer can quickly dissolve in water to perform its function of viscosity building and friction reduction. Therefore, this pH-sensitive modified-polyacrylamide polymer emulsion shows a fast dissolution rate with a dissolution time of about 1 min and a long storage stability. The utilization of stimuli-responsive surfactants to construct pH-responsive water-soluble polymer W/O emulsions provides a new approach to the preparation of water-soluble polymer emulsion additives that can be quickly dissolved and stored for long periods of time in water-treatment, papermaking and oil recovery fields.
研究领域:
石油工程
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Qingxiang Kong,Yulei Li,Hang Ma,Qin Zhao,Linjing Yang,Ruidong Xu,Hong Guo
Hydrogen energy as a new type of clean energy has been widely used. Electrolysis is a highly effective method of producing hydrogen from water. Catalysts with low development costs and high efficiency are the focus of current research. A novel Ni–W–P/Mo catalyst for hydrogen evolution reaction (HER) was synthesized by electrodeposition based on a molybdenum mesh. The experimental results show that when the current density is 10 mA/cm2, the best overpotential of Ni–W–P/Mo in alkaline medium is 75 mV. Not only that, the Tafel slope (77 mV/dec) also proves its excellent dynamic performance. In addition, the 60 h stability test at a current density of 10 mA/cm2 indicates an excellent long-term stability performance. Compared with the catalysts reported in recent years, the HER performance of Ni–W–P/Mo is much better than that of most nonprecious metal catalysts. The uniform and regular molybdenum network provides a large area of support for the catalyst, which is conducive to the synthesis and reaction of the catalyst. By doping W, the electronic structure of the catalyst is regulated, and the water decomposition is promoted. The stability of the morphology is also an important factor in improving the activity of the catalyst. The amorphous catalyst synthesized by the electrodeposition method in this work provides a new idea for the research of catalytic materials for hydrogen production by electrolysis of water and has important significance for promoting the development of a hydrogen energy economy.
研究领域:
材料科学
·
电化学
·
能源研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2020
·
IF 3.442
Yuting Song,Wencheng Fang,Caixia Liu,Zhixia Sun,Fengyan Li,Lin Xu
Modification of semiconductor materials by polyoxometalates (POMs) is a promising strategy for increasing their photoelectrocatalytic (PEC) activity. In this work, we synthesized POM-modified CdS composite nanocrystals based on three kinds of Keggin-type mixed-addendum Mo/W POMs (Ag 3 PMo 3 W 9 O 40 , Ag 3 PMo 6 W 6 O 40 , and Ag 3 PMo 9 W 3 O 40 ). This is the first report on the semiconductor properties of the three Keggin-type mixed-addendum Mo/W POMs. Their PEC performances were studied by transient photocurrent responses, electrochemical impedance spectroscopy , and PEC oxidation of As(III) to As(V). The PEC performances of POM-modified CdS composite nanocrystals (CdS/Ag 3 PMo 3 W 9 O 40 , CdS/Ag 3 PMo 6 W 6 O 40 , and CdS/Ag 3 PMo 9 W 3 O 40 ) were superior to the performance of pure CdS nanocrystals. CdS/Ag 3 PMo 3 W 9 O 40 composite nanocrystals exhibited the highest efficiency for the PEC oxidation of As(III) to As(V), which was about 85% higher than that of the pure CdS nanocrystals. The present study provides insight into developing novel composite nanocrystals with Keggin-type mixed Mo/W POMs for efficient PEC oxidation.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2024
·
IF 1.7
Lin Guangqiang,Mao Chunfeng,Li Menghua,Wang Ziyi,Li Qinyi,Zhan Jiaqing,Liu Junsheng
In this study, Zn–W–Bi–O catalysts with a sandwich structure were prepared by mixing zinc tungstate and bismuth nitrate to form bismuth tungstate at the interface. The catalyst was composed of bismuth nitrate as the upper layer, zinc tungstate as the lower layer, and phase interface (bismuth tungstate) as the core. The generation of phase interfaces provides a new reaction mechanism for catalytic processes. Based on the different intermediate state changes in the reaction process, the Zn–W–Bi–O catalysis system can be divided into H-S Mechanism, B-R Mechanism, and P-G Mechanism. These reaction mechanisms will simultaneously react with H 2 O 2 to generate various transition states, which will cooperatively oxidize sulfur atoms to remove them. The structural characteristics and stability of Zn–W–Bi–O catalysts were determined. There are strong stability and catalytic efficiency for Zn–W–Bi–O catalysts. The desulfurization rate can be close to 100% under optimal conditions (Catalyst of 0.02 g, ionic liquids of 0.5 mL, H 2 O 2 of 0.2 mL, model oil of 5 mL, 80 °C). Zn-W-Bi-O-2 catalysts lead to 3 times improvement in ODS activity for the upper layer and 1.25 times improvement in ODS activity for the lower layer. The catalytic reaction mechanism was obtained by the structure-activity relationship.
研究领域:
化学工程
·
催化材料
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Changyan Ji,Zhi Huang,Xiuying Tian,Hengping He,Jin Wen,Yangxi Peng
A series of red emitting phosphors Mg 3 Y 2-x Ge 3 O 12 :xSm 3+ (0≤x ≤ 0.06) were successfully synthesized. Samples Mg 3 Y 2-x Ge 3 O 12 :Sm 3+ exhibited a cubic structure pertaining to the I a-3d (230) space group and the particle sizes range from 1 μm to 5 μm. The optical properties displayed that the optimum doping concentration of Sm 3+ is 4%. The phosphor Mg 3 Y 1.96 Ge 3 O 12 :0.04Sm 3+ not only exhibited a broad band gap of 5.54 eV but also showed a high color purity of 97.6%. In addition, the strongest emission intensity located at 566 nm belonged to the 4 G 5/2 → 6 H 5/2 transition when excited at 405 nm. Thermal quenching test revealed that the sample Mg 3 Y 1.96 Ge 3 O 12 :0.04Sm 3+ are excellent powders with splendid thermal stability, in which only 3.6% of the PL intensity is quenched at 473 K in comparison with that of 298 K. As a result, the W-LEDs based on Mg 3 Y 1.96 Ge 3 O 12 :0.04Sm 3+ yielded a high R a of 91.1, a low CCT of 4881 K, and CIE coordinates of (0.3476, 0.3466) in a 20 mA driven current. This research work provided important guidance for the synthesis of Sm 3+ doped red component with excellent luminesce properties and high thermal stability characteristics used in W-LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2022
·Vol. 14
·期 14
·e202200341
·
IF 5.497
Junxiu Zhao,Bo Hou,Heqin Guo,Litao Jia,Pengyu Niu,Congbiao Chen,Hongjuan Xi,Debao Li,Jianli Zhang
Graphical Surface hydroxyl groups of the support play a crucial role for WO x -support interaction. A strong interaction between WO x species and support can improve the dispersion of WO x species and generate more WO x -support interface Brønsted acid sites, which are beneficial for 1,3-propanediol synthesis in glycerol hydrogenolysis. For Pt-WO x -based catalysts, researchers pay much attention to study the influence of Pt-WO x interaction on glycerol hydrogenolysis, ignoring the interaction between WO x and support. Herein, four Pt/W/SiZr-T catalysts with different surface hydroxyl groups on support are prepared and characterized. The results show that bibridged (OH II ) and tribridged hydroxyl groups (OH III ) on SiZr-T supports could react with WO x species through forming Zr−O−W bands and retard the agglomeration of WO x species. The highly dispersed WO x species and Zr−O−W bands are the origination of inherent and in-situ generated Brønsted acid, which are beneficial for 1,3-propanediol synthesis. As a result, Pt/W/SiZr-70 exhibits outstanding performance due to abundant OH II and OH III on SiZr-70. The initial space time yield of 1,3-propanediol on Pt/W/SiZr-70 reaches 2.280 g 1,3-PDO ⋅ g cat −1 ⋅ h −1 , the highest among reported results. This r esearch reveals the role of WO x -support interaction on glycerol hydrogenolysis and provides a new direction to design Pt-WO x -based catalysts for selective hydrogenation reactions.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Shanshan Duan,Xun Wang,Ruipeng Ren,Yongkang Lv
One of the most effective methods of utilizing CH 4 and CO 2 resources is the dry reforming of methane (DRM). However, the small particle size and the metal-support interactions of Ni–W bimetallic catalysts are key factors affecting activity and carbon deposition . This article evaluates the effect of Ni–W bimetallic catalysts synthesized by different preparation methods on their catalytic performance in DRM reactions. The results show that the bimetallic catalyst prepared by the solid-state grinding method exhibits excellent catalytic performance and anti-carbon deposition performance. The conversion rate of CH 4 and CO 2 remain unchanged during 1450 min, which is 58% and 66%, respectively. Through various characterization methods, it has been proven that the bimetallic catalyst prepared by the solid-state grinding method effectively reduces the size of Ni particles and increases the number of exposed active sites. In addition, this method also enhances the metal-support interactions, which helps to improve the stability of the catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2018
·Vol. 120
·期 5
·1700471
·
IF 2.2
Lingyi Liu,Zhou Jin,Min Wang,Wangyang Shen,Zhenzhou Zhu,Zhan Wang,Lianliang Liu
Natural phenolic compounds have been drawn a wide attention to replace the synthesis antioxidants due to the food safety issues, while, natural phenolic compounds are usually polyhydroxy derivatives which exhibit hydrophilic capacity, limiting their applications directly in lipid systems. In this work, olive leaf phenolics (OLP) are extracted by ultrasound from five cultivars and the optimal cultivar is chosen to prepare W/O nano-emulsions of Sacha Inchi oil (SIO, containing more than 90% polyunsaturated fatty acids). The droplet size could reach 2.15 ± 0.13 nm and remaines stable without phase separation during 30-day storage. Oxidative stabilities of SIO containing 0.02%, 0.05%, and 0.1% OLP (w/w) are evaluated by Rancimat test and accelerated storage test. The release of OLP by preparation of W/O nano-emulsions is capable of controlling the oxidative progress of SIO, by prolonging the induction time, preventing the production of primary and secondary oxidative products and also the deterioration of polyunsaturated fatty acids and tocopherols. Practical Applications : Sacha Inchi oil (SIO) contains approximately 90% of polyunsaturated fatty acids (PUFAs) associated with poor oxidative stability. Olive leaf phenolics (OLP) are considered as a great and cheap source of natural phenolic compounds. This study aimes to select the optimum source of OLP from five cultivars and to prepare a W/O nano-emulsion of OLP. By diluting the W/O nano-emulsion of OLP into SIO, effect of different concentrations OLP on the oxidative stability of SIO is evaluated through thermal oxidative stability and storage oxidative stability in an accelerated storage test. Results indicate that the capacity of OLP to retard the SIO oxidation depends on the incorporated concentration, which means that it is doable to adopt OLP, an abundant and cheap material, to improve the stability of edible oil with high PUFAs in the industry. Olive leaf phenolics are extracted and detected to prepare an efficient and stable W/O nano-emulsion; By diluting W/O nano-emulsion into Sacha Inchi oil, oxidative stability of the high content PUFAs oil is improved.
研究领域:
食品科学
·
植物化学
·
抗氧化研究
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Guangzhou Hu,Wenying Fu,Yuxiao Lin,Yuanchao Yue,Maosen Wang,Pengbo Liu,Yinwei Li,Jianwei Li,Lu Wei,Xinsheng Zhao,Yongsheng Wei
Electrochemical water splitting to produce clean hydrogen (H2) and oxygen (O2) has emerged as an advanced technology to build a sustainable society. Low-cost electrocatalysts with excellent performance are required to improve the energy efficiency in overall water splitting. Here, a Co-W-B-P/CF catalyst with a nanoflower-like structure consisting of microspheres and nanoflakes was successfully synthesized using a one-step double-pulse electrodeposition approach. When used as a bifunctional electrocatalyst for overall water splitting, Co-W-B-P/CF presented the potentials of 1.57 and 1.86 V at current densities of 10 and 100 mA cm–2 in 1.0 M KOH solution, respectively. This was even comparable to that of the high-cost commercial catalyst Pt/C(−)//IrO2(+). Detailed electrochemical tests also showed that the kinetics, electron transfer, and intrinsic electrocatalytic activity of Co-W-B-P/CF in the HER (hydrogen evolution reaction) and the OER (oxygen evolution reaction) were dramatically improved due to the synergetic effect of co-doped B and P elements. Considering the excellent electrocatalytic performance of Co-W-B-P/CF, along with the simple synthesis method and low cost, bifunctional electrocatalyst Co-W-B-P/CF for overall water splitting is promising.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ChemNanoMat
·
2018
·Vol. 4
·期 5
·487-495
·
IF 3.173
Zhinian Li,Shenliang Wang,Wei Hong,Shihui Zou,Liping Xiao,Jie Fan
Graphical Smart screens : An intelligent approach was developed to screen Na−Mn−W/SiO 2 catalysts for the oxidative coupling of methane (OCM). Effective composition regions other than the standard composition were successfully excavated. The wide range of the optimal composition allowed a fluctuation of composition during the reaction, which secured its excellent stability in the OCM reaction. Optimizing the performance and understanding the mechanism of metal oxide catalysts in the oxidative coupling of methane (OCM) is one of the most important projects in industrial catalysis. Here, we report an intelligent approach to screen Na−Mn−W/SiO 2 catalysts for the OCM reaction via ink-jet printing and multidimensional group testing. The ink-jet-printing-assisted (IJP-A) synthetic methodology ensured a fast synthesis of 1536 catalysts that were evaluated in 24 tests via a multidimensional group testing strategy (m-GT). After two-round synthesis-and-screening processes, several excellent groups with different composition space were screened out. Among the excellent catalysts, the OCM performance of Na−Mn−W/SiO 2 catalyst with higher Na, Mn and W content (G3 and G7) was less sensitive to its constituent than that of Na−Mn−W/SiO 2 catalyst with lower Na, Mn and W content (G1). These results indicated the sensitivity of performance to its Na, Mn and W content decreased in larger Na, Mn and W spaces, consistent with the complex homogeneous/heterogeneous reaction mechanism and multi-active sites. A series of Na−Mn−W/SiO 2 formulas with good performance also provide a reasonable explanation to its excellent stability for the OCM reaction. In addition, this intelligent optimization in total space offers a pathway to study the multicomponent metal oxide catalyst in the OCM reaction.
研究领域:
化学工程
·
催化
·
材料科学
✓ 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）