Enhanced anti-migration performance of carbon nanotubes confined ferrocenyl compounds and their synergistic catalytic activity on the thermal decomposition of ammonium perchlorate

Abstract

To retard high-migration issues of the commercialized ferrocene-based burning rate catalysts (BRCs), six commercial ferrocenyl derivatives (FcR), including catocene, N, N-dimethylaminomethyl ferrocene, n-butylferrocene, tert-butylferrocene, n-octylferrocene and ferrocene, were filled into carbon nanotubes (CNTs) by ultrasonication. The CNTs incorporated ferrocene nanocomposites (FcR@CNTs) were characterized by TEM, SEM, BET, XPS, FTIR, Raman and XRD techniques, which indicated that the ferrocenes are successfully filled into the CNTs. The anti-migration and anti-volatility tests unveiled that the FcR@CNTs exhibit neglectable migration tendency after four weeks of aging at 50 °C and low volatility when tested at 70 °C for 24 h. The combustion catalytic results displayed that the FcR@CNTs nanocomposites play a vital role in promoting the thermal decomposition of ammonium perchlorate (AP), with the best one lowering the peak temperature of high-temperature decomposition stage (HTD) of AP by 114.2 °C and increasing its released heat by 160%. And it was found that the smaller the diameter of a CNT is, the lower the peak temperature of AP and the higher the released heat of AP. In addition, the decomposition mechanism of AP catalyzed by FcR@CNTs(L1) was studied by thermal decomposition kinetics, in-situ solid FTIR and TG-FTIR-MS methods. The results revealed that the nanocomposites can absorb more generated NH3 and HClO4 gases during AP decomposition with formation of superoxide anions (O2−), accelerating the oxidation of N2O to NO, and promoting the AP decomposition at lower temperature. Thus, a possible decomposition mechanism of AP catalyzed by FcR@CNTs is proposed.