One-step electrocatalytic synthesis of ammonia and acetone from nitrogen and isopropanol in an ionic liquid

2021 ◽  
Author(s):  
Qikun Zhang ◽  
Ya'nan Zhao ◽  
Liping Yu ◽  
Xiaoyang Zhang ◽  
Yiling Bei ◽  
...  

Electrocatalysis is an environmentally friendly synthesis method that overcomes thermodynamic limitations and enables some reactions usually requiring high temperature and high pressure to be realized under ambient conditions. The one-step...

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2055 ◽  
Author(s):  
Lin Qi ◽  
Chen-Yu Guo ◽  
Meng-Ge Huang Fu ◽  
Yan Zhang ◽  
Lu-meng Yin ◽  
...  

A new methodology for enhancing the solvent resistance of electrospun polyimide (PI) ultrafine fibrous mat (UFM) was investigated in the current work. For this purpose, a negative intrinsically photosensitive polyimide (PSPI) resin was prepared by the one-step high- temperature polycondensation procedure from 3,3’,4,4’-benzophenonetetracarboxylic dianhydride (BTDA) and α,α-bis(4-amino-3,5-dimethylphenyl)phenylmethane (PTMDA). The PI varnish, by dissolving the derived PI (BTDA-PTMDA) resin in N,N-dimethylacetamide (DMAc) at a solid of 20 wt %, was used as the starting material for the standard electrospinning (ES) and ultraviolet-assisted ES (UVAES) fabrications, respectively. The 365 nm wavelength of the high-pressure mercury lamp ultraviolet (UV) irradiation induced the photocrosslinking reaction in the PSPI mat. Solubility tests indicated that the PI UFM fabricated by standard ES procedure showed poor DMAc resistance, while the one by UVAES (PI-UV) exhibited excellent resistance to DMAc.


2007 ◽  
Vol 70 (9) ◽  
pp. 2168-2171
Author(s):  
JONG-KYUNG LEE ◽  
SARA MOVAHEDI ◽  
STEPHEN E. HARDING ◽  
BERNARD M. MACKEY ◽  
WILLIAM M. WAITES

To find the range of pressure required for effective high-pressure inactivation of bacterial spores and to investigate the role of α/β-type small, acid-soluble proteins (SASP) in spores under pressure treatment, mild heat was combined with pressure (room temperature to 65°C and 100 to 500 MPa) and applied to wild-type and SASP-α−/β− Bacillus subtilis spores. On the one hand, more than 4 log units of wild-type spores were reduced after pressurization at 100 to 500 MPa and 65°C. On the other hand, the number of surviving mutant spores decreased by 2 log units at 100 MPa and by more than 5 log units at 500 MPa. At 500 MPa and 65°C, both wild-type and mutant spore survivor counts were reduced by 5 log units. Interestingly, pressures of 100, 200, and 300 MPa at 65°C inactivated wild-type SASP-α+/β+ spores more than mutant SASP-α−/β− spores, and this was attributed to less pressure-induced germination in SASP-α−/β− spores than in wild-type SASP-α+/β+ spores. However, there was no difference in the pressure resistance between SASP-α+/β+ and SASP-α−/β− spores at 100 MPa and ambient temperature (approximately 22°C) for 30 min. A combination of high pressure and high temperature is very effective for inducing spore germination, and then inactivation of the germinated spore occurs because of the heat treatment. This study showed that α/β-type SASP play a role in spore inactivation by increasing spore germination under 100 to 300 MPa at high temperature.


2019 ◽  
Vol 116 (2) ◽  
pp. 211
Author(s):  
Shengli Wu ◽  
Xiaobo Zhai ◽  
Tiankai Song

A sintering burden blending model is an intelligent system used to obtain the optimal blending proportions of burdens with minimal sintering burden cost. In this study, micro-sintering and sinter pot tests were first carried out to clarify the quantitative relationship between the shatter index (SI) of the sinter and high-temperature characteristics (HTCs) of the ore blends. The result shows that the lowest assimilation temperature (LAT) plays a dual role in SI, whereas the index of liquid phase fluidity (ILF) and compressive strength of the bonding phase (CSB) have positive effects on SI. The effect of the ILF is the largest. Based on the one-step optimization method, suitable ranges of room-temperature characteristics (RTCs) of ore blends, obtained relationship between sinter strength and HTCs of ore blends, sintering theory, and bisection and simplex algorithms, the proposed sintering burden blending model is established. The validation for the model shows that it is effective at utilizing iron ore resources, maintaining high strength of the sinter, while reducing burden costs.


ChemInform ◽  
2009 ◽  
Vol 40 (22) ◽  
Author(s):  
Borislav Bogdanovic ◽  
Michael Felderhoff ◽  
Andre Pommerin ◽  
Ferdi Schueth ◽  
Nick Spielkamp ◽  
...  

1991 ◽  
Vol 44 (6) ◽  
pp. 771 ◽  
Author(s):  
JW Perich ◽  
RM Valerio ◽  
PF Alewood ◽  
RB Johns

A solid phase method is described for the synthesis of O- phosphoseryl-containing peptides by the use of polystyrene resin (Merrifield) as the peptide support and protected Boc-Ser(PO3R2)-OH derivatives for the incorporation of the phosphorylated seryl residue. The viability of this solid phase approach was demonstrated by the synthesis of HBr.H-Glu-Ser (PO3Et2)-Leu-OH in high yield by the use of Bo -Ser(PO3Et2)-OH in peptide synthesis and subsequent use of HBr/CF3CO2H for cleavage of the Ser(PO3Et2)-containing tripeptide from the resin support. Similarly, the dipeptide, CF3CO2H.H-Ser(P)- Leu -OH, was prepared in high yield by using Boc -Ser(PO3But2)-OH in peptide synthesis followed by the one-step deprotection of the Ser(PO3But2)- dipeptide resin by treatment with HBr/CF3CO2H (90 min). Alternatively, the O-phosphoseryl tripeptide , CF3CO2H.H-Glu-Ser(P)- Leu -OH was prepared by using either Ppoc -Ser(PO3Bzl2)-OH or Boc-Ser(PO3Ph2)-OH in peptide synthesis. The one-step deprotection of the Ser(PO3Bzl2)-containing tripeptide and cleavage of the peptide from the resin support was effected by high-pressure hydrogenolysis (palladium acetate). In the case of phenyl phosphate protection, the Ser(PO3Ph2)-containing peptide was cleaved from the resin support by high-pressure hydrogenolysis (palladium acetate) followed by cleavage of the phenyl phosphate groups by platinum-mediated hydrogenolysis (1.0 equiv. PtO2/phenyl group) in 50% CF3CO2H/AcOH.


1998 ◽  
Vol 547 ◽  
Author(s):  
J.-H. Park ◽  
P.M. Woodward ◽  
J.B. Parise ◽  
I. Lubomirsky ◽  
O. Stafsudd

AbstractA new perovskite was recovered from the high pressure-high temperature treatment of the α-TlSbO3 form of Na2SnTeO6 at 7 GPa and 950 °C for 30 minutes. Synchrotron x-ray powder diffraction data show the space group is P21/n with a=5.40361 (5), b=5.46152(5), c=7.69288(7) Å and ß=90.034(3)°. Using disk samples of both polymorphs, the dielectric properties were measured as a function of temperature. At ambient conditions, the perovskite form has a more than 1.5 fold enhancement in dielectric constant compared to the α-TlSbO3 form while the molar volume and the molecular polarizability decrease.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Chunhua Liang ◽  
Hui Liu ◽  
Jianmin Zhou ◽  
Xiaochun Peng ◽  
Haizhou Zhang

Maghemite (γ-Fe2O3) nanopowders were synthesized under aeration (oxidizing) conditions by aqueous synthesis in this study. The microstructures of the prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET-BJH. The XRD analysis and the chemical experiments showed that well-crystallized γ-Fe2O3 nanoparticles were successfully obtained with a mean particle size of approximately 17 nm. The prepared γ-Fe2O3 was spherical with a BET surface area of 14.357 m2/g and a total pore volume of 0.050 cm3/g. Varying the reaction conditions, such as pH, temperature, and reaction time, we obtained crystallized γ-Fe2O3 powders with different crystallization extent and different particle sizes. When the pH of the reaction suspension was increased, the reaction time was prolonged, and the reaction temperature was increased, the γ-Fe2O3 powders underwent superior crystallization and had larger particle sizes. All the obtained γ-Fe2O3 powders had significant photocatalytic activities under both UV and visible light irradiation for Orange I degradation, and the powders with better crystallization and larger particle size had relatively lower activities for Orange I photocatalytic degradation. The one-step aqueous synthesis method presented in this paper may provide an advantageous pathway to synthesize large quantities of this important iron oxide.


2009 ◽  
Vol 83-86 ◽  
pp. 810-817
Author(s):  
Elodie Lefort-Sorlier ◽  
Christophe Colin ◽  
Alfazazi Dourfaye

Continuous composition gradients of several millimetres were generated in commercial WC-Co cutters to improve their shock resistance. This important gradation was obtained in one-step by using the imbibition process. The effects of this thermal processing were analysed in terms of microhardness, cobalt concentration and WC grain size. A gradient of a 300 HV amplitude is measured in the 8 mm-height sample treated by the imbibition process in association with a boron-rich coating. This gradient was preserved after the HPHT (high pressure – high temperature) step used for the diamond table deposition on the WC-Co cutter. To our knowledge, such gradients have never before been reported and should certainly increase cutter service life.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7604
Author(s):  
Hasan Shabbir ◽  
Tomasz Tokarski ◽  
Ditta Ungor ◽  
Marek Wojnicki

In this work, we report the synthesis method of carbon quantum dots (CDs) using the one-step method for fast and effective metal ion determination. Ascorbic acid was used as an inexpensive and environmentally friendly precursor. High-pressure and high-temperature reactors were used for this purpose. Microscopic characterization revealed the size of CDs was in the range of 2–6 nm and they had an ordered structure. The photoluminescence properties of the CDs depend on the process temperature, and we obtained the highest PL spectra for 6 h of hydrothermal reaction. The maximum emission spectra depend poorly on synthesis time. Further characterization shows that CDs are a good contender for sensing Fe3+ in aqueous systems and can detect concentrations up to 0.49 ppm. The emission spectra efficiency was enhanced by up to 200% with synthesis time.


2019 ◽  
Vol 19 (11) ◽  
pp. 7436-7441
Author(s):  
Chu Zhang ◽  
Qi-Yu Wang ◽  
Ming-De Li ◽  
Guo-Dong Zhang

Sub-micrometer particles of β-Bi2O3 were successfully synthesized via a one-step self-propagating high-temperature synthesis (SHS) method for the first time. The experiments were carried out in the air at room temperature. The products were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In this study, three experiments were designed to optimize the heat source, Bi source and additive for the reaction system. Results showed that the system composed of Al, Bi2O3 and Al2O3 powders could synthesize monodisperse high-purity β-Bi2O3 spherical particles with the average diameter of 369 nm and the as-prepared products kept stable after being exposed in air for one month. Then, the influences of the ratio of the three components on system were investigated. Interestingly, it was found that a slight adjustment on the ratio of Al:Bi2O3:Al2O3 had significant effects on the reactions happening in a system. Specifically, when the amount of Al2O3 exceeds the molar ratio of 2:1:1 (Al:Bi2O3:Al2O3), it is difficult to ignite the reaction system; when the amount is less than 2:1:0.5, the reaction system becomes too violent to obtain pure products. However, there are no obvious differences on the morphology and structure of final products with the two ratios because of few changes in adiabatic temperature. Preparation of β-Bi2O3 by SHS technique enjoying many advantages, such as high efficiency, inexpensive experimental equipment and simple processes, would has a promising prospect for industrial application.


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