scholarly journals Determination of Molybdenum Species Evolution during Non‐Oxidative Dehydroaromatization of Methane and its Implications for Catalytic Performance

ChemCatChem ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 473-480 ◽  
Author(s):  
Miren Agote‐Arán ◽  
Anna B. Kroner ◽  
Husn U. Islam ◽  
Wojciech A. Sławiński ◽  
David S. Wragg ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Species Evolution

scholarly journals Quantitative determination of residual silver distribution in nanoporous gold and its influence on structure and catalytic performance

2017 ◽  
Vol 352 ◽  
pp. 52-58 ◽  
Author(s):  
Christoph Mahr ◽  
Paromita Kundu ◽  
Anastasia Lackmann ◽  
Daniele Zanaga ◽  
Karsten Thiel ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Catalytic Performance ◽  
Nanoporous Gold

scholarly journals Oxidase-Like Catalytic Performance of Nano-MnO2 and Its Potential Application for Metal Ions Detection in Water

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Kai Sun ◽  
Qingzhu Liu ◽  
Rui Zhu ◽  
Qi Liu ◽  
Shunyao Li ◽  
...  
Keyword(s):  
Metal Ions ◽  
Potential Application ◽  
Cost Effective ◽  
Catalytic Performance ◽  
Single Electron Transfer ◽  
Environment Monitoring ◽  
Electron Transfer Process ◽  
Relative Errors ◽  
Metal Ions Detection

Certain nano-scale metal oxides exhibiting the intrinsic enzyme-like reactivity had been used for environment monitoring. Herein, we evaluated the oxidase-mimicking activity of environmentally relevant nano-MnO2 and its sensitivity to the presence of metal ions, and particularly, the use of MnO2 nanozyme to potentially detect Cu2+, Zn2+, Mn2+, and Fe2+ in water. The results indicated the oxidase-like activity of nano-MnO2 at acidic pH-driven oxidation of 2,6-dimethoxyphenol (2,6-DMP) via a single-electron transfer process, leading to the formation of a yellow product. Notably, the presence of Cu2+ and Mn2+ heightened the oxidase-mimicking activity of nano-MnO2 at 25°C and pH 3.8, showing that Cu2+ and Mn2+ could modify the reactive sites of nano-MnO2 surface to ameliorate its catalytic activity, while the activity of MnO2 nanozyme in systems with Zn2+ and Fe2+ was impeded probably because of the strong affinity of Zn2+ and Fe2+ toward nano-MnO2 surface. Based on these effects, we designed a procedure to use MnO2 nanozyme to, respectively, detect Cu2+, Zn2+, Mn2+, and Fe2+ in the real water samples. MnO2 nanozyme-based detecting systems achieved high accuracy (relative errors: 2.2–26.1%) and recovery (93.0–124.0%) for detection of the four metal ions, respectively. Such cost-effective detecting systems may provide a potential application for quantitative determination of metal ions in real water environmental samples.

scholarly journals Analysis of biological spectrum of Divcibare flora

2006 ◽  
pp. 143-154
Author(s):  
Ivana Popovic ◽  
Dragica Obratov-Petkovic
Keyword(s):  
Environmental Effects ◽  
Life Form ◽  
Balkan Peninsula ◽  
Study Region ◽  
Floristic Study ◽  
Study Results ◽  
Species Evolution ◽  
Basic Characteristics ◽  
Biological Spectrum

One of the essential analyses which is performed during the floristic study of a region is the analysis of the biological spectrum. The analysis of the biological spectrum of the flora includes the determination of the type of life form for each taxon described in the flora of the study region. If it is considered that life form is a specific structural-functional response to the environmental effects and the result of the adaptation during the species evolution, it is clear that the basic characteristics of the site are more or less reflected in any life form. This fact is confirmed by the analysis of the biological spectrum of Divcibare flora. The study results are in correlation with the results of the analysis of the biological spectrum of the flora of Serbia and the Balkan Peninsula.

scholarly journals Analysis of the biological spectrum of vascular flora of Ravni Srem flood forests

2011 ◽  
pp. 57-70
Author(s):  
Branislav Jurisic ◽  
Dragica Obratov-Petkovic ◽  
Ivana Bjedov ◽  
Nenad Bojat ◽  
Vladimir Stevanovic
Keyword(s):  
Functional Response ◽  
Environmental Effects ◽  
Life Form ◽  
Study Region ◽  
Vascular Flora ◽  
Floristic Study ◽  
Species Evolution ◽  
Basic Characteristics ◽  
Biological Spectrum

One of the essential analyses performed during the floristic study of a region is the analysis of the biological spectrum. The analysis of the biological spectrum of the flora includes the determination of the type of life form for each taxon described in the flora of the study region. If it is considered that life form is a specific structural-functional response to the environmental effects and the result of the adaptation during the species evolution, it is clear that the basic characteristics of the site are more or less reflected in any life form. This fact is confirmed by the analysis of the biological spectrum of the flora of Ravni Srem. The analysis of the Ravni Srem flora shows the domination of the hemicryptophytes and the subdomination of the phanerophytes with a considerable participation of the therophytes.

Evolution of iron species for promoting the catalytic performance of FeZSM-5 in phenol oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (39) ◽  
pp. 32789-32797 ◽  
Author(s):  
Lei Luo ◽  
Chengyi Dai ◽  
Anfeng Zhang ◽  
Junhu Wang ◽  
Chunshan Song ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Phenol Oxidation ◽  
Iron Species ◽  
Species Evolution

Facile modification of FeZSM-5 utilizing an organic directing agent (ODA) for iron species evolution toward better Fenton activity was developed.

Determination of the Presence of Composite Ions in Catalysts and Composite Ionic Liquids-Catalyzed Isobutane Alkylation

2011 ◽  
Vol 287-290 ◽  
pp. 1666-1670 ◽  
Author(s):  
Ying Nan Cong ◽  
Ying Liu ◽  
Rui Sheng Hu
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ir Spectroscopy ◽  
Catalytic Performance ◽  
Ir Absorption ◽  
Absorption Bands ◽  
Alkyl Groups ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A novel and efficient method was established to investigate isobutane/2-butene alkylation. In this method FT-IR spectroscopy was used to determine the presence of the composite ion (AlCuCl5-) in the composite ionic liquid (CIL). The trimethylpentane selectivity of the composite ionic liquid for isobutane/2-butene alkylation was also estimated by monitoring the shift of IR absorption bands in the range 1636–1685 cm-1. A detailed study of the alkylation of isobutane /2-butene in CIL media has been conducted using 1-alkyl-3-methylimidazolium halide/X aluminum chloride-y cuprous (I) chloride ([CnMIM]Cl/xAlCl3-yCuCl) encompassing various alkyl groups (n=4:B, butyl-, n=6:H, hexyl-, and n=8: O, octyl-)respectively. The ionic liquids showed higher selectivities of C8 as well as the TMP/DMH ratios in alkylates. The better catalytic performance of CIL can be attributed to the presence of the composite ion in it, and the catalytic performance of the chloroaluminate ionic liquid can be indicated by the 1685 cm-1band of FT-IR spectroscopy.

Facile immobilization of lipase based on Pickering emulsion via a synergistic stabilization by palygorskite–enzyme

Clay Minerals ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 293-298
Author(s):  
Dong Li ◽  
Min Shen ◽  
Guofan Sun ◽  
Huiran Jin ◽  
Peng Cai ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Immobilized Lipase ◽  
Aqueous Dispersion ◽  
Pickering Emulsion ◽  
Catalytic Performance ◽  
Pickering Emulsions ◽  
Emulsion Droplets ◽  
Level Of Activity ◽  
High Level

AbstractA Pickering emulsion was prepared via synergistic stabilization of a lipase and palygorskite particles. The optimum conditions for the stabilization of the Pickering emulsion, such as the concentrations of the palygorskite particles and lipase, were explored. The morphology of emulsion droplets was examined using digital optical microscopy and polarizing optical microscopy. The palygorskite–lipase co-stabilized Pickering emulsions were investigated by determination of the adsorption rate, pH and zeta potential of the aqueous dispersion, as well as by determining the contact angle values of the lipase solution on a palygorskite disc that was immersed in toluene. The catalytic performance of the immobilized lipase in the Pickering emulsion was studied via the investigation of its thermal stability, storage stability and reusability. The immobilized lipase showed greater stability than the free lipase. The lipase immobilized by Pickering emulsion retained a high level of activity even after seven periods of recycling.

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