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61.
《International Journal of Hydrogen Energy》2020,45(38):19304-19312
Reasonable design and preparation of non-noble metal electrocatalysts with predominant catalytic activity and long-term stability for oxygen evolution reaction (OER) are essential for electrocatalytic water splitting. Ni foam (NF) is highlighted for its 3D porous structure, impressive conductivity and large specific surface area. Herein, nano/micro structured dendritic cobalt activated nickel sulfide grown on 3D porous NF (Co–Ni3S2/NF) has been successfully synthesized by one-step hydrothermal method. Due to the ingenious incorporation of Co, Co–Ni3S2/NF electrode shows auspicious electrocatalytic performance for OER compared with Ni3S2/NF electrode. As a result, Co–Ni3S2/NF needs overpotential of only 274 and 459 mV at current density of 10 and 50 mA cm−2, respectively, while Ni3S2/NF requires overpotential of 344 and 511 mV. At potential of 2.0 V (vs. RHE), Co–Ni3S2/NF displays current density of 191 mA cm−2, while Ni3S2/NF just attains current density of only 135 mA cm−2. Moreover, Co–Ni3S2/NF demonstrates excellent stability for uninterrupted OER in alkaline electrolyte. The strategy of designing and preparing cobalt activated nickel sulfide grown on NF renders a magnificent prospect for the development of metal-sulfide-based oxygen evolution catalysts with excellent electrocatalytic performances. 相似文献
62.
为诠释柱状晶贵金属兼具优良超细丝加工性能及高电阻率的原因,采用水平连铸、水冷铜模铸造及石墨模铸造,分别获得了具有20 μm×60 μm的柱状晶、10 μm的等轴晶、以及5 μm的表面细晶+长径比约为3的柱状晶+30 μm的芯部等轴晶三晶区的三种Ag-28Cu-0.75Ni合金棒材,研究了晶粒形态、尺寸对Ag-28Cu-0.75Ni合金棒材超细丝加工性能及电阻率的影响。结果表明:与等轴晶和三晶区Ag-28Cu-0.75Ni合金棒材相比,柱状晶棒材由于其较低的位错密度(1.78×1015 m-2)及显微硬度变化率(33.3%)、铸态断口无解理台阶,表现了出最低的加工硬化率,且铸态轴向抗拉强度高达384.6 MPa,可实现100 m以上、直径0.05 mm超细丝高效不断丝加工;加工态及退火态的柱状晶Ag-28Cu-0.75Ni合金超细丝均表现出了较高的电阻率,经两次连续退火后电阻率高达3.68 μΩ.cm,与其较低的位错密度及加工硬化率有关。 相似文献
63.
Ammaru Ismaila Huanhao Chen Yan Shao Shaojun Xu Yilai Jiao Xueli Chen Xin Gao Xiaolei Fan 《中国化学工程学报》2020,28(9):2328-2336
Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals. In this context, catalytic steam reforming of glycerol (SRG) was proposed as a promising and sustainable alternative for producing renewable hydrogen (H2). Herein, the development of nickel (Ni) supported on ceria-modified mesoporous γ-alumina (γ-Al2O3) catalysts and their applications in catalytic SRG (at 550–750 °C, atmospheric pressure and weight hourly space velocity, WHSV, of 44,122 ml·g−1·h−1 (STP)) is presented. Properties of the developed catalysts were characterised using many techniques. The findings show that ceria modification improved Ni dispersion on γ-Al2O3 catalyst support with highly active small Ni particles, which led to a remarkable catalytic performance with the total glycerol conversion (ca. 99%), glycerol conversion into gaseous products (ca. 77%) and H2 yield (ca. 62%). The formation rate for H2 production (14.4 × 10−5 mol·s−1·g−1, TOF (H2) = 3412 s−1) was significantly improved with the Ni@12Ce-Al2O3 catalyst, representing nearly a 2-fold increase compared with that of the conventional Ni@Al2O3 catalyst. In addition, the developed catalyst also exhibited comparatively high stability (for 12 h) and coke resistance ability. 相似文献
64.
65.
《International Journal of Hydrogen Energy》2020,45(29):14728-14743
The main objective of the present work is to investigate the influence of nickel to cerium ratio on hydrogen exchanged Zeolite Socony Mobil-5 (HZSM-5) towards the catalytic upgrading of pine derived oxygenated pyrolysis vapours into aromatic hydrocarbon and phenol in pyrolysis oil via ex-situ fixed bed reactor. The presence of CeO2 could change electron density of Ni, promote the reduction of Ni species, accelerate the transfer of carbon species, and suppress the production of carbon deposits (17.53%–25.11%) compared with the parent HZSM-5 catalyst (28.95%); it also improved the hydrodeoxygenation ability of all xNiyCe/HZSM-5(nickel and cerium bimetal modified HZSM-5) catalysts, resulting increases in noncondensable gas content (from 31.46% to 52.99%–65.53%). Ni to Ce ratio of 1:1 and 1:2 produced highest aromatic hydrocarbon (32.14%) and phenols (55.51%) relative peak areas. The acid center of HZSM-5 and the metal acid center of the Ni:Ce = 1:1 catalyst obviously fine-tuned the formation of coke; and promoted hydrocarbon production. Moreover, high Ni content promoted alkylation of benzene at C6–C9 and increased C10+ PAHs relative peak area; high Ce content promoted the formation of olefin and Increasing the cleavage of C–O bonds and promoted hydrogenation or dehydrogenation, reduced polycyclic aromatic hydrocarbons and coke yield, and increased phenols and alkylphenols selectivity. 相似文献
66.
Ordered mesoporous Ni/Silica-carbon as an efficient and stable catalyst for CO2 reforming of methane
《International Journal of Hydrogen Energy》2019,44(10):4809-4820
Ordered mesoporous silica-carbon (MSC) were used as supports of Ni based catalysts for dry reforming of methane (DRM) reaction. The effects of preparation method and precipitant on the catalysts are investigated. The physical and chemical properties are discussed based on the H2-TPR, FTIR, XRD, TEM, H2-TPD and N2 adsorption/desorption characterization. It is found that the preparation method and choice of precipitants affect the catalysts significantly in terms of the properties and catalytic performance in DRM reaction. In detail, the catalysts prepared by the precipitation method show more highly dispersed Ni particles and further better catalytic activity than the impregnated catalyst. That is attributed to the forming Ni3Si2O5(OH)4 nanoflakes in the catalyst precursors with the existence of alkaline precipitants. And this Ni3Si2O5(OH)4 species bind the support more tightly than NiO in the impregnated Ni/MSC catalyst. Moreover, the choice of precipitants also influences the form of Ni3Si2O5(OH)4 species in the catalysts. Specially, the strong electrolytic capacity of NaOH gives the most Ni3Si2O5(OH)4 nanoflakes formed in Ni-MSC-1 catalyst, which results in the most highly Ni dispersity and further highest catalytic activity. Besides, the strong interaction between the Ni3Si2O5(OH)4 species and support are also advantageous to the resist sintering and formation of carbon deposition, that is related to the good catalytic stability of catalysts. 相似文献
67.
《International Journal of Hydrogen Energy》2019,44(16):8233-8242
To investigate the effect of support materials on catalytic performance in carbon dioxide reforming of coke oven gas, Ni-based catalysts supported on various metal oxides with various properties are prepared and evaluated. The support material affects the important properties related to the catalytic performance such as surface area, Ni dispersion, basicity, oxygen storage capacity, and interaction between Ni and support. Among the various catalysts on different metal oxides, Ni/MgOAl2O3 catalyst exhibits the highest CH4 conversion due to its high Ni dispersion, large surface area, and strong basicity. Hence, the Ni loading in the Ni/MgOAl2O3 catalyst is optimized. Ni loading performs the important roles to determine the Ni dispersion, the amount of Ni active sites, and basicity. 15 wt% Ni/MgOAl2O3 catalyst shows the highest catalytic activity even at a high gas hourly space velocity (GHSV) of 1,500,000 h−1, owing to the large amount of Ni active sites which related to Ni loading, Ni dispersion, and reduction degree. To confirm the stability of the 15 wt% Ni/MgOAl2O3 catalyst, catalytic reaction has been carried out for 50 h and noticeable catalytic deactivation is not observed for 50 h. 相似文献
68.
摘要:为研究溶解氧质量浓度对10Ni5CrMo钢在阴极极化条件下氢脆敏感性影响规律,对10Ni5CrMo钢进行了阴极极化下的电化学交流阻抗谱测试﹑并采用慢应变速率拉伸实验和断口分析方法研究了海水中溶解氧质量浓度变化和不同阴极极化下10Ni5CrMo钢的氢脆敏感性。结果表明:溶解氧质量浓度变化对10Ni5CrMo钢强度几乎没有影响;同一溶解氧质量浓度下,随极化电位负移,断裂时间、伸长率、断面收缩率明显降低,氢脆系数增加,氢脆敏感性显著提高,极化电位达到-1000mV时,氢脆系数已超过安全区允许的最高值25%,进入危险区;同一极化电位下,随着海水中溶解氧质量浓度减少,材料塑性变差,断裂时间、伸长率和断面收缩率不断降低,氢脆系数增加,氢脆敏感性提高。 相似文献
69.
《International Journal of Hydrogen Energy》2022,47(29):13803-13814
High-strength steel parts are electroplated with corrosion-resistant coatings and then subjected to hydrogen removal annealing to prevent hydrogen embrittlement. This approach has become the standard in the industry. However, it is not beneficial to energy conservation and emission reduction. Herein, a rare earth salt (Ce salt) additive is determined to be efficient for inhibiting hydrogen permeation during electroplating process. A modified Devanathan-Stachurski method was applied to investigate the hydrogen permeation behavior. Results demonstrated that the hydrogen permeation during direct current (DC) and pulsed current (PC) electrodeposition was considerably inhibited by the Ce salt additive. The amount of permeated hydrogen increased in the following order: PC electrodeposition with Ce<PC electrodeposition<DC electrodeposition with Ce<DC electrodeposition. Therefore, the environmentally friendly additive has great potential for energy saving and emission reduction in the electrodeposition or pickling industry. 相似文献
70.
《International Journal of Hydrogen Energy》2022,47(79):33765-33780
This work investigates selective Ni locations over Ni/CeZrOx–Al2O3 catalysts at different Ni loading contents and their influences on reaction pathways in ethanol steam reforming (ESR). Depending on the Ni loading contents, the added Ni selectively interacts with CeZrOx–Al2O3, resulting in the stepwise locations of Ni over CeZrOx–Al2O3. This behavior induces a remarkable difference in hydrogen production and coke formation in ESR. The selective interaction between Ni and CeZrOx for 10-wt.% Ni generates more oxygen vacancies in the CeZrOx lattice. The Ni sites near the oxygen vacancies enhance reforming via steam activation, resulting in the highest hydrogen production rate of 1863.0 μmol/gcat·min. In contrast, for 15 and 20-wt.% Ni, excessive Ni is additionally deposited on Al2O3 after the saturation of Ni–CeZrOx interactions. These Ni sites on Al2O3 accelerate coking from the ethylene produced on the acidic sites, resulting in a high coke amount of 19.1 mgc/gcat·h (20Ni/CZ-Al). 相似文献