查找使用阿拉丁产品的科研文献

A Polyurethane Organic Framework for Flexible Al–Air Batteries

Songmao Zhang,Yichun Wang,Yawen Li,Manhui Wei,Keliang Wang

Flexible Al–air batteries with hydrogels are regarded as a promising power source owing to their high specific capacity, their high ionic conductivity, and having no leakage. However, the mechanical properties of the hydrogels remain unresolved. Here, we present a polyurethane organic framework (POF) employing a polyurethane skeleton as an internal support for poly(acrylic acid) (PAA) hydrogel, where the POF can exhibit high strength and toughness, and an Al–air battery using the POF can output good electrochemical properties. The results demonstrate that the tensile stress of 30 ppi POF is 49.5 kPa owing to the stress-transfer mechanism, while that of PAA is only 3.1 kPa. Compared to that of the PAA hydrogel, the discharging capacity of Al–air batteries with 20 ppi POF can be increased by 79 mAh cm–2 at a current density of 1 mA cm–2, which can be attributed to corrosion inhibition and the surface roughness change of the POF during the discharging process. This work will deliver a selectable strategy for a trade-off between mechanical and electrochemical properties.

Highly reactive Al–Cr2O3 coating for electric-explosion applications

Daixiong Zhang,Qing Xiang,Xueming Li

As a nanoenergetic material with high energy density, nanothermite coatings composed of metal and oxidant have potential applications in electric-explosion devices. In this study, a novel highly reactive Al–Cr2O3 coating was successfully fabricated via electrophoretic deposition (EPD) technology. Moreover, with the advantage of high fabrication rate by employing high concentration of Al and Cr2O3 nanoparticles, an electric-explosion device with successful explosion could be easily obtained via assembling an Al–Cr2O3 coating onto Cu electric-explosion bridges in only 1 minute, which is much more efficient than other coating technologies. More importantly, considering the successful preparation of other reactive coatings in previous work, we also believe that EPD is a promising general strategy for rapidly preparing electric-explosion device with many other nanoenergetic material coatings such as nanothermite and bimetallic reactive composites.

Microstructured Al/Fe2O3/Nitrocellulose Energetic Fibers Realized by Electrospinning

Rui Li,Hongmei Xu,Hailong Hu,Guangcheng Yang,Jun Wang,Jinpeng Shen

Promoted CF4 Decomposition via Enhanced Tricoordinated Al Active Sites

Xiaojian Wang,Hang Zhang,Yingkang Chen,Jialin Zheng,Heping Chen,Kang Liu,Junwei Fu,Zhang Lin,Liyuan Chai,Min Liu

Tetrafluoromethane (CF4), as a typical perfluorocarbon (PFC), has a remarkable global warming potential (GWP) of 7390 and an ultralong lifetime of 50 000 years, making its effective treatment crucial for mitigating environmental impact. Catalytic hydrolysis is a promising way for its effective decomposition, in which Al-based materials have been widely used as efficient catalysts. However, the deficiency of strong Lewis acidic-tricoordinated Al (AlIII) sites strongly limits their catalytic performance. In this work, efficient CF4 decomposition was achieved via promoting AlIII sites over ZnAl2O4 through a facile acid treatment strategy. Among various acid treatments, it was found that H2SO4 treated ZnAl2O4 could achieve 100% CF4 decomposition under a relatively low temperature of 600 °C and kept above 70% removal for over 160 h running. The 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra demonstrated that the proportion of AlIII was increased from ∼0% of the pristine one to 7.5% after H2SO4 treatment. Pyridine-infrared (Py-IR) spectroscopy and NH3 temperature-programmed desorption (NH3-TPD) and CF4-TPD tests indicated that the amount of acid sites and the adsorption capacity of CF4 were dramatically improved after acid treatment. This work proposes a new strategy to improve CF4 decomposition.

Catalytic Depolymerization of a Lignin-Rich Corncob Residue into Aromatics in Supercritical Ethanol over an Alumina-Supported NiMo Alloy Catalyst

Yunfei Bai,Kai Cui,Yushuai Sang,Kai Wu,Fei Yan,Fuhang Mai,Zewei Ma,Zhe Wen,Hong Chen,Mengmeng Chen,Yongdan Li

A one-pot process for the depolymerization of lignin-rich corncob residue (LRCR) is investigated in supercritical ethanol over an alumina-supported NiMo (NiMo/Al) alloy catalyst. The LRCR, as a major byproduct in the corncob enzymatic hydrolysis process, was completely liquefied and effectively transformed into aromatic compounds without the formation of tar or char under optimal reaction conditions. The reaction temperature, time, solvent, and initial hydrogen pressure have significant effects on the depolymerization of LRCR. The highest overall aromatic yield of 255.4 mg/g of LRCR with 57.9 wt % alkylphenols (e.g., 4-ethylphenol, 2,5-diethylphenol, and 2,6-diisopropylphenol) was achieved with an initial 27.6 bar (gauge) of hydrogen in supercritical ethanol at 320 °C for 7.5 h. The depolymerization of LRCR is also examined over Ni/γ-Al2O3, Mo/γ-Al2O3, and the physical mixture of these two catalysts. The NiMo/Al alloy catalyst exhibits much higher activity than that of other catalysts, and a synergistic effect between Ni and Mo active species is proposed. Furthermore, X-ray powder diffraction results show that the Mo1.24Ni0.76 alloy is expected to be an important active species for the depolymerization reaction.

Multi-catalytic active site biochar-based catalysts for glucose isomerized to fructose: Experiments and density functional theory study

Kang Xiheng,You Zi,Huang Yongheng,Peng Jian,Zhang Junhua,Ragauskas Arthur J.,Zhang Zhanying,Song Xueping

This work provides an innovative method for preparing different isomerization catalysts by impregnating different proportions of MgCl 2 and AlCl 3 and combining different K compounds on cellulose-derived biochar, followed by pyrolysis. Results show MgO and Al(OH) 3 existing in 4 Mg- 1 Al-C catalyst can obtain better catalytic effect on glucose isomerization than the singe of Al presenting in 0 Mg- 1 Al-C catalyst. Moreover, the synergism effects of the multi-catalytic active sites such as β- , γ-Al(OH) 3 , KCl, MgO, and K 4 H 2 (CO 3 ) 3 in Mg-Al-KHCO 3 -C catalyst can further lead to an increase in glucose isomerization, compared to the 4 Mg- 1 Al-C catalyst. The X-ray diffraction results present that the value of O/Al in Mg-Al-KHCO 3 -C catalyst is as high as 13.38, which provides many unsaturated acidic catalysis sites and benefits the glucose isomerization. Simultaneously, the TPD results reveal that the main active sites (MgO, Al(OH) 3 , and K 4 H 2 (CO 3 ) 3 ) in Mg-Al-KHCO 3 -C catalyst can provide weakly acidic and basic sites and avoid strongly acidic and basic sites to excessively attack the glucose. Based on the DFT analysis, the results indicate that the MgO has a great effect on the ring-opening reaction to form acyclic glucose, while Al(OH) 3+ has a great effect on promoting acyclic glucose hydrogen transfer isomerized to form fructose. Compared to other carbon-based metal catalysts, the prepared Mg-Al-KHCO 3 -C has excellent catalytic performance, which gives a higher fructose yield (38.7%) and selectivity (87.72%) and glucose conversion (44.12%) at 100 °C in 30 min. In this study, we develop a highly efficient Mg-Al-K-biochar catalyst for glucose isomerization and provide an efficient method for cellulose valorization.

Synthesis of porous Al doped ZnO nanosheets with high adsorption and photodecolorizative activity and the key role of Al doping for methyl orange removal

Xiaohua Sun,Weilong Luo,Linlin Chen,Linjie Zheng,Chao Bao,Panpan Sun,Niu Huang,Yihua Sun,Liang Fang,Lei Wang

Porous Al doped ZnO (AZO) nanosheets have been prepared as an efficient multifunctional water treatment material. Their fundamental properties were characterized by various spectroscopic testing methods. The AZO nanosheets displayed very rapid adsorption rate and high adsorption capacity for methyl orange (MO) dye. The kinetics and equilibrium of adsorption process were found to follow the pseudo-second-order kinetic and Langmuir isotherm models, respectively. Furthermore, the AZO nanosheets exhibited superior photodecolorizative activity compared with the commercial P25 TiO2 nanoparticles. It was found that Al doping increased the zeta potential of AZO nanosheets and then significantly enhanced the adsorption capacity for MO dye and, at the same time, retarded the recombination of photoexcited electron–hole pairs, and prolonged the lifetime of the photo-generated carriers, and then improved the semiconductor photocatalytic activity. In addition, the visible-light-driven dye photosensitized degradation was also an important reason for enhanced photodecolorizative activity. Therefore, AZO nanosheets are a potential multifunctional water treatment material combining highly efficient adsorption and photocatalytic degradation.

The Effect of Annealing on Electrochemical Performances of an Al–Sn–Ga–Mg Alloy as an Anode for Al–air Batteries in Alkaline Electrolytes

Zhaohui Han,Yang Xu,Shenggang Zhou,Lei Xu,Peixian Zhu

In this study, an Al-0.08Sn-0.08Ga-0.5Mg alloy was annealed at 200 °C–400 °C for 10 h. The microstructure and corrosion morphology of the Al anode were observed by scanning electron microscopy (SEM), and the effects of different annealing temperatures on the electrochemical properties of the Al anodes were studied by the hydrogen evolution rate, open circuit potential, Tafel curves, EIS and constant current discharge. The results show that the annealing treatment had a certain effect on the number and size of precipitates on the alloy surface, which improved the electrochemical activity and corrosion resistance of the Al alloy. Additionally, the Al–Sn–Ga–Mg alloy anode material has an excellent discharge performance in the actual use process when the annealing temperature is 350 °C, the related performance parameters were greatly improved compared with other annealing temperature conditions. The capacity density is 2670.99 mAh·g−1, and the energy density is 3379.15 mWh·g−1.

High-performance Al-doped Cu/ZnO catalysts for CO2 hydrogenation to methanol: MIL-53(Al) source-enabled oxygen vacancy engineering and related promoting mechanisms

Guiming Xie,Xingyang Bai,Yi Man,Pengju Ren,Rongrong Jin,Runduo Zhang,Kostya (Ken) Ostrikov,Zhou-jun Wang,Qingyuan Yang

Innovative catalyst design and in-depth mechanism understanding are imperative for industrialization of CO 2 hydrogenation to methanol. Herein, Al-doped Cu/ZnO catalysts, Cu/Al-ZnO-x (x = 1/32, 1/16 and 1/8, denoting Al/Zn molar ratio), were creatively synthesized using MIL-53(Al) as Al sources and reactive templates. The Cu/Al-ZnO-1/16 catalyst exhibited the highest methanol production rate among the Cu/Al-ZnO-x catalysts, which was 1.93 times as active as the conventional Cu/Al-ZnO-1/16-C catalyst using Al(NO 3 ) 3 ·9H 2 O as Al source. Structural characterizations reveal that the use of MIL-53(Al) led to higher S BET , more uniform Al distribution, more abundant oxygen vacancies, more appropriate metal-support interactions and larger amount of medium basic sites. Mechanism studies demonstrate that Al doping would markedly induce oxygen vacancy formation on Cu-ZnO interfaces and thus significantly boost methanol synthesis activity. This work offers a facile approach to develop efficient methanol synthesis catalysts and provides new insights into the nature of Al promotion in Cu/ZnO-based catalysts.

Electrochemical Performance of Al-1Zn-0.1In-0.1Sn-0.5Mg-xMn (x = 0, 0.1, 0.2, 0.3) Alloys Used as the Anode of an Al-Air Battery

Wenfeng Zhang,Tongrui Hu,Tao Chen,Xiaowei Yang,Yunfeng Zhu,Tainian Yang,Liquan Li

In this work, Al-1Zn-0.1In-0.1Sn-0.5Mg-xMn (x = 0, 0.1, 0.2, 0.3) alloys are prepared and used as the anode of an Al-air battery (AAB). We use scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) and optical microscopy (OM) to analyze the microstructures of the alloys. The hydrogen evolution rate, electrochemical performance (including polarization curves), electrochemical impedance spectroscopy (EIS), and battery performance of the samples are examined in the 4 M NaOH electrolyte. The experimental data display that the average grain size is significantly refined after adding manganese into the Al-1Zn-0.1In-0.1Sn-0.5Mg alloy, with a decrease in grain size from over 100 μm to about 10 μm. The improved activity of the aluminum anode in the AAB can be attributed to the introduction of manganese. The Al-1Zn-0.1In-0.1Sn-0.5Mg-0.1Mn alloy possesses the optimal overall performance with a lower self-corrosion rate (0.128 mL∙cm−2∙min−1), the highest working potential (1.630 V) and energy density (2415 mWh·g−1), a higher capacity (1481 mAh·g−1) and anodic utilization (49.75%).Keywords:aluminum alloy;aluminum-air battery;self-corrosion;grain size;electrochemical performance

β-Diketiminate Aluminum Dihydride is a Valuable Precursor for the Preparation of Acyclic and Cyclic Systems

Shuai-Cong Huo,Yao Li,Peng-Fei Ji,De-Xiang Zhang,Zhi-Jiao Zhang,Ying Yang,Herbert W. Roesky

Treatments of β -diketiminate aluminum dihydride LAlH 2 (L=HC[C(Me)N(Ar)] 2 , Ar=2,6- i Pr 2 C 6 H 3 ) with (2-chlorophenyl)methanol, 2,3-dimethylbutane-2,3-diol, 2,2-dimethylpropane-1,3-diol, 2,2-bis(bromomethyl)propane-1,3-diol, and p -diphenol resulted in the formation of compounds containing the C−O−Al−O−C linkages, including the acyclic LAl[( μ -O)CH 2 ( o -Cl−C 6 H 4 ) 2 ] 2 ( 1 ), the five-membered ring LAl[( μ -O)CMe 2 ] 2 ( 2 ), the six-membered ring LAl[( μ -O)CH 2 ] 2 CMe 2 ( 3 ) and LAl[( μ -O)CH 2 ] 2 C(CH 2 Br) 2 ( 4 ), and the macrocyclic [LAl( μ -O) 2 ( p -C 6 H 4 )] 4 ( 5 ), respectively. These practices prove that β -diketiminate aluminum dihydride is a valuable precursor for the preparation of acyclic and cyclic systems. 1 – 5 were characterized by melting point, 1 H and 13 C NMR, FT-IR, and single-crystal X-ray diffraction studies.

A garnet-structured (Y, Ca)3(Al, Mg)2(Al, Si)3O12:Ce3+ phosphor-in-glass engineering for use in high color rendering white LEDs

Tu Huan,Zhao Guoying,Hou Jingshan,Liu Yufeng,Zhou Yan,Zhang Ganghua,Sun Hong-Tao,Li Ji-Guang,Fang Yongzheng

White light emitting diodes (LEDs) suffer from two most common drawbacks: the deficiency of the red component and the poor thermal stability of silicone. Ce 3+ -doped garnet phosphors with tailor-made luminescence properties can be achieved by variations in {A}, {B}, and {C} cation sites. Herein, a simultaneous ion co-substitution design strategy has been adopted to synthesize a series of (Y, Ca) 3 (Al, Mg) 2 (Al, Si) 3 O 12 garnet phosphors and corresponding phosphor-in-glass (PiG) films. The co-substitution is finely restricted to the assigned sites. The emission peak is shifted from 529 to 565 nm, which is beneficial to obtain low color temperatures and high color rendering using a single phosphor for white LEDs. By employing the as-synthesized phosphor, the corresponding PiG films were fabricated by the low temperature co-sintering technology using the SiO 2 –B 2 O 3 –ZnO–Na 2 O glass system characterized with excellent thermal stability and moisture resistance. The morphological and elemental analyses demonstrated that the as-made phosphor powders were uniformly distributed in the glass host without any interfacial reactions. Finally, modular white LEDs with a high color rendering (Ra = 82.7) is achieved through the as-synthesized PiG film on an InGaN blue chip. This study may open up a facile approach to obtain high quality luminescence based on the mono-luminescence center, avoiding excitation energy wastage and low quantum efficiency aroused by multi-luminescence centers or color compensation phosphors in glass.