A new catalyst, H(3)PO(4)/MoO(3)/SiO(2), was prepared by modification of MoO(3)/SiO(2) using phosphoric acid. The characterization of the catalyst was performed using Infrared and Raman Spectroscopy, potentiometric titration and nitrogen adsorption-desorption methods. Molybdenum oxides were identified along with phosphomolybdic acid and polymolybdates on the modified surface. The suitability of the catalysts for toluene and chlorobenzene nitration in continuous process was examined. Toluene is effectively nitrated to dinitrotoluene (DNT) in one-stage process (96 wt.% of DNT in the product) and in mild conditions i.e. at room temperature and only with ten-fold excess of nitric acid. In chlorobenzene nitration only twelve-fold excess of nitric acid is needed to obtain as high yield as 95 wt.%. Most importantly, the novel catalysts we have developed, provide the opportunity for sulfuric acid- free nitration of aromatic compounds.
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http://dx.doi.org/10.1016/j.jhazmat.2011.08.031 | DOI Listing |
Talanta
January 2025
Ministry of Education (MOE) Key Laboratory of Bioinorganic and Synthetic Chemistry, Ministry of Education, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, PR China; School of Chemical Engineering and Technology, Sun Yat-sen University, and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 519082, Zhuhai, PR China; Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center Guangzhou), 100 Xianlie Middle Road, Guangzhou, 510070, PR China; Chemistry College, Center of Advanced Analysis and Gene Sequencing, Zhengzhou University, Kexue Avenue 100, Zhengzhou, 450001, PR China.
Macrocyclic polymer materials exhibit excellent selectivity and adsorption performance in pollutant adsorption due to unique host-guest recognition. Herein, three kinds of calixarene polymers (C4P, C6P and C8P) were synthesized through Sonogashira reaction, and were characterized through H NMR, FT-IR, SEM, and TEM. The water contact angle experiments revealed that three kinds of calixarene polymers were highly hydrophobic, and they all exhibited high enrichment efficiency for weak polar chloro-substituted benzene compounds (chlorobenzene, o-chlorotoluene, p-dichlorobenzene and o-dichlorobenzene) and BTEX (benzene, toluene, ethylbenzene and xylenes).
View Article and Find Full Text PDFEnviron Geochem Health
December 2024
School of Mechanical Engineering, Tongji University, Shanghai, 200092, China.
Environmental exposures to volatile organic compound (VOC) mixtures have received increasing attention, yet the risks are under studied. This study aimed to explore the risks of combined exposures to several commonly detected VOCs and to draw attention to the necessity of studying long-term and low-concentration environmental exposure patterns. In this study, we examined the effects of long-term and low-concentration exposures to VOCs like 1,2-dichlorobenzene, benzene, toluene and formaldehyde either alone or in combination on D.
View Article and Find Full Text PDFMolecules
November 2024
Department of Applied Chemistry, School of Chemistry, Xi'an Jiaotong University, No. 28, Xianning West Road, Xi'an 710049, China.
A series of Fe-Ba mixed oxides, including a pure Fe-containing sample as a reference, have been synthesized via a sol-gel process using Fe or Fe salts and BaSO as raw materials, with Pluronic P123 serving as a template. These oxides have been thoroughly characterized and subsequently utilized as catalysts for the chlorination of various organic molecules. Commercial hydrochloric acid, known for its relative safety, and environmentally friendly aqueous hydrogen peroxide were employed as the chlorine source and oxidant, respectively.
View Article and Find Full Text PDFSoft Matter
November 2024
School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
Video imaging was used to study large-slope folded telephone cord blister formation in solvent swollen films of polydimethylsiloxane (PDMS) elastomers. Chlorobenzene, chloroform, heptane and toluene were used to swell PDMS films with thickness values in the range 15 μm < < 223 μm supported on glass substrates. Measurements of the blister width, corrugation wavelength and blister growth speed were studied as a function of the film thickness for all four solvents.
View Article and Find Full Text PDFBioresour Technol
January 2025
Civil Engineering Department, University of Nebraska-Lincoln (Omaha Campus), Omaha, NE 68182, USA.
Aromatic volatile organic compounds (VOCs) are prevalent pollutants in chemically contaminated sites, posing threats to ecological safety and human health. To address the challenge of achieving low-carbon, low-cost, green, and sustainable in-situ remediation at these sites, a highly efficient synthetic bacterial consortium was constructed for biodegradation of selected pollutants (i.e.
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