posted on 2024-01-19, 22:32authored byQiangqiang Lu, Yiwen Hu, Junqing Yang, Hongyu Yang, Lei Xiao, Fengqi Zhao, Hongxu Gao, Wei Jiang, Gazi Hao
Understanding the decomposition process of ammonium nitrate
(AN)
on catalyst surfaces is crucial for the development of practical and
efficient catalysts in AN-based propellants. In this study, two types
of nano-Fe2O3 catalysts were synthesized: spherical
particles with high-exposure (104) facets and flaky particles with
high-exposure (110) facets. Through thermal analysis and particle
size analysis, it was found that the nanosheet-Fe2O3 catalyst achieved more complete AN decomposition despite
having a larger average particle size compared to nanosphere-Fe2O3. Subsequently, the effects of AN pyrolysis on
the (110) and (104) facets were investigated by theoretical simulations.
Through studying the interaction between AN and crystal facets, it
was determined that the electron transfer efficiency on the (110)
facet is stronger compared to that on the (104) facet. Additionally,
the free-energy step diagrams for the reaction of the AN molecule
on the two facets were calculated with the DFT + U method. Comparative
analysis led us to conclude that the (110) facet of α-Fe2O3 is more favorable for AN pyrolysis compared
to the (104) facet. Our study seeks to deepen the understanding of
the mechanism underlying AN pyrolysis and present new ideas for the
development of effective catalysts in AN pyrolysis.