A kinetic study of the thermal degradation of cetyltrimethylammonium bromide inside the mesoporous SBA-3 molecular sieve

The thermal degradation of cetyltrimethylammonium bromide (CTMAB) inside the mesoporous SBA-3 was studied under non-isothermal conditions. There are two distinct and complex kinetic processes which partly overlap, each consisting of one dominant and three minor individual processes. The two dominant processes can be described by the Sestak-Berggren model. The main decomposition step (the first dominant process) involves the overcoming of weak interactions between CTMAB and the silica network and proceeds with a lower Ea value (116 +/- 2 kJ mol(-1)) than the second dominant process (153 +/- 5 kJ mol(-1)), which can be explained by the size reduction of the pore openings due to the contraction of the SBA-3 unit cell caused by the removal of CTMAB.