Detail Studies of nanocrystalline magnesium oxide by adsorption of molecular probes and as a destructive adsorbent for chemical warfare agent mimics Bibliografi Author: Lucas, Erik Michael ; Klabunde, Kenneth J. (Advisor) Topik: CHEMISTRY; INORGANIC|CHEMISTRY; GENERAL Bahasa: (EN )    ISBN: 0-599-75865-1     Penerbit: KANSAS STATE UNIVERSITY     Tahun Terbit: 2000     Jenis: Theses - Dissertation Fulltext: 9970817.pdf (0.0B; 0 download) Abstract The Lewis acid sites and destructive adsorptive ability of a high surface area, aerogel produced, nanoparticle magnesium oxide powder (AP-MgO) were compared with that of microparticle (CP-MgO) and commercial MgO (CM-MgO). The characterization of Lewis acid sites was achieved by the adsorption of molecular probes. Destructive adsorption studies were performed on the mimics of dangerous compounds. Carbon monoxide adsorption, observed using a spring balance, showed that the number of CO molecules adsorbed on the surface of AP-MgO, 3.2/nm 2, to be greater than CP-MgO, 2.5/nm 2 or CM-MgO, 1.0/nm 2. The adsorption of the molecular probes, carbon monoxide and d3-acetonitrile, was monitored with infrared spectroscopy in a special low pressure cell with the oxide mounted on a tungsten grid. Carbon monoxide adsorption was performed at −170°C at pressures of 0.05–15.0 Torr as well as after evacuation. d3-Acetonitrile adsorption was performed at 25°C at pressures of 0.05–15.0 Torr. Results showed that AP-MgO has a greater number of comer, edge and defect sites than the CP and CM-MgO. They also showed that all adsorption sites had a larger acidity than the corresponding sites on CP and CM-MgO. The destructive adsorption of chemical warfare mimics was studied using 2-chloroethyl ethyl sulfide (a mimic of sulfur mustard), hexafluoropropylene (a mimic of perfluoroisobutylene) and chloroacetonitrile (a mimic of cyanogen chloride). 2-Chloroethyl ethyl sulfide was dehydrohalogenated to form ethyl vinyl sulfide and MgCl2. Reactions proceeded at 25°C, and vinyl production was monitored using infrared spectroscopy. Hexafluoropropylene and chloroacetonitrile destruction was monitored using pulse reactions at temperatures of 25°–500°C. Hexafluoropropylene destruction was best accomplished with AP-MgO at 450°, with 100% conversion to CO and MgF2 with some CO2 produced as a side product. AP-MgO and CP-MgO showed equal reactivities with chloroacetonitrile, and less than 20% conversion was realized at 300°C or lower. The destructive ability of AP-MgO actually decreased at 500°C, even showing lower conversion rates than CP-MgO for chloroacetonitrile. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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