Chapter Ten - Preparation, Characterization, and Catalytic Activity of Carbon Nanotubes-Supported Metal or Metal Oxide

Abstract

Several carbon nanotubes (CNTs)-supported metals or metal oxides as combustion catalysts, such as Pb/CNTs, Ag/CNTs, Pd/CNTs, NiPd/CNTs, PbO/CNTs, CuO/CNTs, Bi2O3/CNTs, MnO2/CNTs, CuO·PbO/CNTs, Cu2O·Bi2O3/CNTs, Bi2O3·SnO2/CNTs, Cu2O·SnO2/CNTs, NiO·SnO2/CNTs, and CuO·SnO2/CNTs, were prepared and characterized by X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectrometry SEM-EDS, transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR). The effects of catalysts on the properties of energetic materials, such as nitrocellulose (NC) absorbed nitroglycerin (NG) (NC-NG), hexogen (RDX), ammonium perchlorate (AP), and N-guanylurea-dianitramide (GUDN) were investigated, and the catalytic mechanisms were elucidated. Upon introduction of the CNTs-supported catalysts, thermal decompositions of these energetic materials were significantly enhanced. In addition, the catalysts were applied in the double–base (DB) propellants and the composite modified double-base (CMDB) propellants, and the combustion catalytic effects were studied. CuO/CNTs, Bi2O3/CNTs, Pb/CNTs, NiB/CNTs, and NiPd/CNTs were introduced into the DB propellants as catalysts, among which CuO/CNTs showed the best catalytic effect, the burning rate of CuO/CNTs-added DB propellant at 6MPa was increased by 115% in comparison with the pristine one Bi2O3·SnO2/CNTs, CuO·PbO/CNTs, Cu2O·Bi2O3/CNTs, CuO·SnO2/CNTs, and NiO·SnO2/CNTs were tested as combustion catalysts in CMDB propellants, and the catalytic effects of these catalysts on propellant combustion were evident, especially for CuO·PbO/CNTs. The addition of CuO·PbO/CNTs increased the burning rate of CMDB propellant at 6MPa by more than 100%. The synergistic effect of CNTs and metal oxide nanoparticles on the decomposition and combustion reactions of energetic materials were believed to be responsible for significantly enhanced combustion performance of CuO/CNTs- and CuO·PbO/CNTs-added propellants, which makes them promising for applications in solid rocket propellants.