FUEL
·
2022
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IF 8.035
Han-Bing Gao,Le-Le Qiu,Fa-Peng Wu,Jian Xiao,Yun-Peng Zhao,Jing Liang,Yong-Hui Bai,Fang-Jing Liu,Jing-Pei Cao
Catalytic hydrogenolysis of C O bonds in lignin provides a promising route to produce high value-added biofuels and chemicals. However, designing highly active and stable catalysts for this process is still a challenge. Herein, a series of Ni/Al 2 O 3 catalysts were synthesized by calcination and reduction of layered double hydroxide precursors, and their activities were evaluated in the catalytic conversion of lignin-derived compounds. Diphenyl ether was completely converted with a 100% monomeric selectivity (cyclohexane and cyclohexanol) over the optimized Ni/Al 2 O 3 -500 under the optimal conditions of 200 ℃, 0.5 MPa H 2 and 1.5 h, indicating the excellent catalytic activity in the cleavage of C O bonds of the catalyst. The excellent catalytic performances of Ni/Al 2 O 3 -500 were originated from its relatively large specific surface area, well-developed porosity, small crystallite size, high Ni 0 concentration and strong interaction between the active metal and support. The reusability experiments show that Ni/Al 2 O 3 -500 possesses a relatively high stability for six reuses. Moreover, various lignin model compounds can be completely converted to corresponding monomeric products over Ni/Al 2 O 3 -500, indicating the applicability of this ingenious catalyst. The application of the hydrotalcite-derived Ni-based catalysts with high activity and stability provides a promising approach for the efficient hydrogenolysis of lignin derivatives.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Junshuang Zhou,Ying Bian,Zhuoran Hao,Kuo Wei,Jiajia Xiao,Jing Wang,Yuanzhe Wang,Huiyang Gou,Faming Gao
Inhibiting the chlorine evolution reaction (CER) is of great significance for the design and development of oxygen evolution catalysts with high current density for seawater electrolysis. The KOH concentration plays a very important role in controlling the potential of chlorine evolution in seawater electrolysis. However, the effect of its concentration, especially the high one (for example, >1 M), on the OER activity of different catalysts has not been studied so far. Here, we found that the KOH concentration has different linear effects on the OER activity for different catalysts, and we first propose a novel concept named concentration activity coefficient (CAC) to express the linear relationship between the OER activity of the catalyst and the KOH concentration in seawater electrolysis. Based on CAC, we report a Co S-NiFe 2 O 4 catalyst with ultrahigh oxygen evolution activity in the 3 M KOH + seawater. This is due to the strong electronic interaction between Co and S-NiFe 2 O 4 . At current densities of 500 mA cm −2 and 1000 mA cm −2 , the overpotentials of Co S-NiFe 2 O 4 are 270 mV, and 287 mV, respectively, which are much lower than those of the existing electrocatalysts . More promising, the new catalysts also showed a splendid Tafel slope of 18.8 mV dec −1 and a long catalytic lifetime in concentrated alkaline electrolyte . Our findings provide a better understanding of the correlation between the KOH concentration and the OER activity and open new avenues for design and development of electrocatalysts for the next generation of high OER activity in seawater electrolysis.
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高影响因子
SOLID STATE SCIENCES
·
2022
·
IF 3.752
Yi Wang,Peng Jiang,M.A. Subramanian,Wenbin Cao
Single phase Al 2-2 x Ni x Ti 1+ x O 5 (0 ≤ x ≤ 0.4) solid solutions were successfully synthesized by solid-phase reaction. The color of the compounds varied from yellow ( x = 0.1) to turmeric ( x = 0.4) with increasing nickel content. X-ray photoelectron spectroscopy analysis confirmed that the oxidation state of Ni is +2. The UV–Vis absorption spectrum showed that the color of the sample comes from the d-d transition of Ni 2+ in octahedral coordination. Owing to excellent high temperature stability, the as-prepared oxide powders (10 wt%) were mechanically mixing with Al 2 O 3 by conventional ball milling to prepare colored alumina ceramics. When Al 2 O 3 is in excess, the blue NiAl 2 O 4 impurity phase appeared, contributing to an intense green color of the Al 2 O 3 ceramics composite. The Vickers micro hardness value of green alumina was higher than that of pure white alumina. The as-prepared samples were also dispersed in PMMA and bright yellow polymer composites were obtained, indicating great potential in polymer colorant.
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高影响因子
SYNTHETIC METALS
·
2023
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IF 4.4
Xinbo Zhao,Mingyu Bei,Fubin Liu,Fan Bu,Xiaohui Jiang,Liangmin Yu
Porous and layered structures can enhance interfacial polarization, and hierarchical porous composites have high dielectric loss, which can improve electromagnetic wave (EMW) absorption performance, but challenges remain. In this paper, flower-like Ni/C nanocomposites with different morphologies were obtained by adjusting the amount of solvent and heat treatment after the Ar atmosphere. The results show that Ni metals lead to magnetic loss and carbon nanotubes lead to conduction loss, and electromagnetic synergy promote enhance interfacial polarization. Moreover, the large specific surface area and hierarchical porous increase the propagation path of electromagnetic waves, resulting in scattering and multiple reflection of the EMW. Therefore, a minimum reflection loss of − 42.8 dB corresponding to an absorption bandwidth of 5.7 GHz was achieved for the Ni/C nanocomposites. This work shows that the MOF-based Ni/C composites can provide a great idea for the design and manufacture of wave-absorbing materials.
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FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Yu Chen,Zemin Zhao,Ze Li,Jieying Jing,Wenying Li
Hydrogenation saturation of phenanthrene was an effective method to acquire high energy density fuels. It is essential to design highly active and stable hydrogenation saturated catalyst to realize the above reaction. Herein, series of Ni-Co/NiAlOx catalysts were synthesized by reducing at different temperatures. Activity evaluation showed that the catalysts reduced at 560 °C (Cat-560) possessed a phenanthrene conversion amount of 8.0 mmol·g -1 active component·h −1 and 98% perhydrophenanthrene selectivity after running 6 h under 300 °C, 5 MPa. Furthermore, it was found that Cat-560 presented superior specific activity (4.3 mmol·kg −1 ·s −1 ) and TOF (41.1 × 10 −3 s −1 ) for symmetric octahydrophenanthrene hydrogenation (the rate determining reaction), and its specific activity was 3 times as high as that of the catalysts reduced at 520 °C The excellent hydrogenation performance of Cat-560 could be attributed to its special geometric and electronic structure. Characterization indicated that the Ni 2+ in Ni-Co/NiAlO X catalyst was mainly located in the nickel aluminum spinel octahedral sites, which was beneficial to the reduction of Ni and the formation of smaller Ni particles. Moreover, it was explored that the Ni d charge density of Cat-560 catalyst was −0.12 e, which was suitable for the adsorption and activation of phenanthrene and symmetric octahydrophenanthrene.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Jiaxing Wang,Shuping Zhang,Lei Ye,Yuanquan Xiong,Huiyan Zhang
Herein, the biochar-supported Ni catalysts was synthesized by carbothermal reduction and its catalytic activity for biomass-derived heavy components was investigated in a pyrolysis-catalysis two stage reactor at the catalytic cracking temperature of 700 °C. The change in catalytic activity of biochar-supported Ni catalyst was divided into three stages according to conversion efficiency of heavy components: rapid reduction stage (from 95.30% to 85.58%), stabilization stage (from 84.65% to 82.98%), and slow reduction stage of activity (from 81.21% to 76.98%), corresponding to rapid decreasing stage (from 88.95% to 63.53%), stable stage (from 62.1% to 57.55%), and slow increasing stage (57.66% to 60.17%) of the mass retention percentage of catalyst. The characterizations of catalyst after different cycles showed that the initial deactivation mainly caused by the sintering of Ni active sites. With the severe sintering of Ni nanoparticles , coke deposition became the main reason of later catalyst deactivation . Particularly, the carbon elimination reaction promoted by highly dispersed Ni particle was observed which contributed to enrich the mesoporous structure and retarded the deactivation of the catalyst. The research marks a further understanding of the interaction and deactivation mechanisms between biochar support and Ni active sites during catalytic cracking of biomass-derived heavy components.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2023
·Vol. 39
·期 4
·673-679
·
IF 3.1
Wang Teng,Hu Renquan,Wei Hao,Wei Zehui,Yan Meng,Yang Yong
Developing low-cost Ni-based amorphous/crystalline composites with well-defined nanostructures is expected to achieve a highly efficient oxygen evolution reaction(OER) by exposing more active sites and enhancing the electrical conductivity, but it still remains a synthetic challenge. Here, a crystalline/amorphous composite composed of crystalline Ni 3 Se 4 and amorphous Ni hydroxide with a multi-layered bowl-shaped nanostructure was synthesized by a simple one-step solvothermal method. By regulating the concentration of sulfate ions in the reaction solution, the single-layered nanosheets achieve a transformation into a multi-layered structure with more exposed active sites. In addition, the crystalline-amorphous heterostructure allows regulation of the interfacial electronic structures, and the decoration of Ni 3 Se 4 can effectively enhance the electrical conductivity of composites. Benefiting from the interfacial synergy between Ni 3 Se 4 and Ni hydroxide, the as-optimized Ni 3 Se 4 /Ni hydroxide as an OER catalyst displayed superior electrocatalytic activity with a low overpotential of 285 mV at a current density of 10 mA/cm 2 , a small Tafel slope of 68.3 mV/dec and remarkable stability in alkaline solution. This work offers a novel and effective method for the design of functional crystalline/amorphous composites for energy conversion and storage.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Hongwang Liu,Yining Zhang,Sibao Liu,Sha Li,Guozhu Liu
Ammonia is a promising hydrogen storage material due to its ease of storage and decomposition to CO x -free hydrogen. Herein, we report colloidal solution combustion synthesis (CSCS) to construct Ni-CeO 2 nanocomposite catalysts for efficient ammonia decomposition to generate hydrogen. Unlike conventional supported Ni/CeO 2 catalyst, the prepared Ni-CeO 2 nanocomposite catalyst exhibited nickel embedded in CeO 2 matrix with enhanced metal-support interaction. The physicochemical properties and metal-support interaction of the catalysts can be tuned by adjusting the amount of silica sol template. The resulted Ni-CeO 2 nanocomposite catalysts exhibited outstanding catalytic performance in terms of activity and stability. The hydrogen production rate reached 32.9 mmol g cat −1 min −1 at 500 °C, which is superior to other state-of-the-art Ni-based catalysts and even comparable or better than some reported Ru-based catalysts. The systematic characterizations demonstrated that the unique Ni-CeO 2 nanocomposite structure with enhanced metal-support interaction, not only provided a rich Ni-CeO 2 interface to stabilize small-sized Ni nanoparticles, but also had a high concentration of oxygen vacancy to strengthen electronic metal-support interaction, making nickel surface electron-rich. The integrated studies of kinetics, temperature-programmed surface reaction, and DFT calculations corroborated that this enhanced metal-support interaction including geometric and electronic effects, favored the enrichment of NH 3 on the catalyst surface and facilitated rate-determining N≡N bond formation step, thereby boosting the reaction rate. This study highlights the importance of designing new structural catalysts with enhanced metal-support interaction for boosting hydrogen production from ammonia decomposition.
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高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Ping-an Yang,Rui Cai,Haibo Ruan,Mingqi Zhao,Xin Huang,Nanqing Zhang,Rui Li,Yuxin Zhang,Jiufei Luo
One-dimensional iron–nickel (Fe–Ni) heterogeneous nanowires with superior electromagnetic wave (EMW) absorption were successfully prepared by a magnetic-field-assisted liquid-phase reduction method. The electromagnetic properties of the absorber were controllably tuned by changing the atomic molar ratio of Fe to Ni. The composite with an Fe:Ni atomic molar ratio of 1:1.5 exhibited the finest EMW absorption characteristics. With a matched thickness of 2.175 mm, the minimum reflection loss (RLmin) at 18 GHz can be as high as 26.106 dB. Also, the majority of the Ku-band is covered by the effective absorption bandwidth (EAB, RL ≤ −10 dB), which is up to 6.08 GHz at 2.6 mm with a filler content of 25%. The excellent absorber performance is due to one’s own rich heterogeneous interface to conciliate the dielectric and magnetic losses. The successful exploration of the one-dimensional heterogeneous structure EMW absorber provides important insights for the future sensible fabrication of absorbers with excellent EMW absorption capability.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 36
·17032-17041
·
IF 3.3
Yan Wang,Guiyang Xian,Chongmei Wu,Zhaolin Zhu,Yin Liu,Zhenying Liu,Ling Bing Kong
Ni@nitrogen-doped polyaniline-derived carbon composite (NC-n) was prepared through in situ polymerization and pyrolytic reduction for electromagnetic wave (EMW) absorption over 2–18 GHz. With polyaniline as the carbon source through carbonization, nitrogen doping was successfully realized, leading to enhanced interfacial polarization, dipole polarization, and defect polarization. In addition, the production of metallic nickel resulted in eddy current loss and magnetic resonance loss, enabling multiple absorption mechanisms. The impedance matching of the NC-n could be optimized by adjusting the composition, which results in a reduction in the reflection EMW at the surface of the materials. Specifically, a reflection loss of −61.93 dB was achieved at a thickness of 1.72 mm, together with an effective absorption bandwidth of 5.68 GHz (12.08–17.76 GHz) at 1.80 mm. This strategy can be used as a reference to design high performance composite EMW absorbers.
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FUEL
·
2022
·
IF 8.035
Xiaoxian Li,Min Lin,Rui Li,Qiang Lu,Mingde Yang,Yulong Wu
In this work, methods employing ethanol for dispersion as well as precursor combination by rotary evaporation were combined to produce Ni-based ZSM-22 catalysts. The catalytic activity in palmitic acid deoxygenation over Ni/Z22@E was enhanced compared with that of the wet-impregnated method. The conversion of palmitic acid reached 98.9 %, in which C16/C15 alkane was as high as 4.07. The Ni species on the surface of catalysts showed strong stability so that not susceptible to inactivation by coking or leaching. In addition, the mechanism and kinetics of the palmitic acid deoxygenation reaction were analyzed. The results showed that the ethanol dehydration reaction was the most difficult to occur, and the high C 16 alkanes selectivity can be attributed to the low activation energy of the hydrodeoxygenation (HDO) pathway. Both experimental and kinetics calculation results suggested that there may be a mechanistic change in the fatty acid deoxygenation reaction at around 240 °C that resulted in a large increase in the hydrodecarboxylation (HDX) pathway. Based on this, selected adjustments of the products were proposed for fatty alcohols below 220 °C, C 16 alkanes between 260 and 280 °C, and C 15 alkanes above 280 °C.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2022
·
IF 8.129
Hao Zhu,Fei Wang,Jianchun Jiang,Zeng Zhang,Yuchan Du,Junfeng Feng,Xiaoxiang Jiang
In order to deal with the deficiency of active sites in Ni catalyst, Ni Fe nanosheet (Ni-Fe/Al 2 O 3 -NS) catalyst was synthesized by using Ni-Fe-Al LDH as the precursor. The catalyst was further utilized in the lipid hydrotreatment for green diesel production. With a lamellar structure and large Ni loading (more than 60%), the Ni-Fe/Al 2 O 3 -NS catalyst possessed abundant Ni sties with high dispersion, large surface area, and strong acidity. Moreover, in Ni-Fe/Al 2 O 3 -NS the highly active Ni 3 Fe phase was formed, which promoted the decarbonylation route in hydrotreatment. The Ni-Fe/Al 2 O 3 -NS catalyst achieved 98.7% conversion with 98.1% alkane yield in oleic acid hydrotreatment under very mild conditions (220 °C, 2 MPa of hydrogen pressure, 3 h). The catalytic performance of Ni-Fe/Al 2 O 3 -NS was much higher than traditional Ni-Fe/Al 2 O 3 and other catalysts reported in current related studies.
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