Silicon-substituted microporous aluminophosphate AlPO4-11 zeolite crystals (SAPO-11) were synthesized by a hydrothermal method. The dipropylamine (DPA) molecules were incorporated in the one-dimensional channels of SAPO-11 as organic templates. The DPA molecules can be pyrolyzed at high temperature, and form 0.3 nm single-walled carbon nanotubes (SWNTs). The detailed carbonization process of DPA molecules has been investigated by using Fourier transform infrared measurements (FTIR), mass spectrometry, fhermogravimeter (TG), and micro-Raman spectroscopy. During the pyrolysis process, the DPA molecules decompose into propylene and ammonia at 673 K, and then the C—H bonds of C3H6 start to break when temperature is above 698 K. The 0.3 nm SWNTs are formed sequentially in the channels of SAPO-11 crystals at about 723 K.
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